1995 GMC Sierra Owners Manual

If YOU have a diesel engine, you will also find a low coolant light on your instrument panel. lf Steam Is Coming From Your Engine

A CAUTION:

if you see or

you badly, even if

Steam from an overheated engine can burn you just open the hood. Stay away from the engine hear steam coming from it. Just turn it off and get everyone away from the vehicle until it cools down. Wait until there is no sign of steam or coolant before opening the hood. If you keep driving when your engine is overheated, the liquids in it can catch fire. You or others could be badly burned. Stop your engine if it overheats, and get out of the vehicle until the engine is cool.

NOTICE: If your engine catches fire because you keep driving with no coolant, your vehicle can be badly damaged. The costly repairs would not be covered by your warranty.

5-10

If No Steam Is Coming From Your Engine If you get the overheat warning but see or hear no steam, the problem may not be too serious. Sometimes the engine can get a little too hot when you:

0 Climb a long hill on a hot day. 0 Stop after high speed driving. 0 Idle for long periods in traffic.

Tow a trailer. See “Driving on Grades’’ in the Index.

If you get the overheat warning with no sign of steam, try this for a minute or so:

1. If you have an air conditioner, turn it off. 2. Turn on your heater to full hot at the highest fan speed and open the

window as necessary.

3. If you’re in a traffic jam, shift to NEUTRAL (N); otherwise, shift to the

highest gear while driving - AUTOMATIC OVERDRIVE (@) or DRIVE (3) for automatic transmissions.

If you no longer have the overheat warning, you can drive. Just to be safe, drive slower for about ten minutes. If the warning doesn’t come back on, you can drive normally. If the warning continues, pull over, stop, and park your vehicle right away. If there’s still no sign of steam, push the accelerator until the engine speed is about twice as fast as normal idle speed. Bring the engine speed back to normal idle speed after two or three minutes. Now see if the warning stops. But then, if you still have the warning, turn ofSthe engine and get everyone out of the vehicle until it cools down. You may decide not to lift the hood but to get service help right away.

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Cooling System - Gasoline Engines

When you decide it’s safe to lift the hood, here’s what you’ll see: A. Coolant recovery tank B. Engine fan(s) C. Radiator pressure cap

I A CAUTION:

If your vehicle has air conditioning, the auxiliary electric fan under the hood can start up even when the engine is not running and can injure you. Keep hands, clothing and tools away from any underhood electric fan.

If the coolant inside the coolant recovery tank is boiling, don’t do anything else until it cools down.

5-12

The coolant level should be a 1 or above the COLD mark. If it isn’t, you may have a leak in the radiator hoses. heater hoses, radiator. water pump or somewhere else in the cooling system.

A CAUTION:

Heater and radiator hoses, and other engine parts, can be very hot. Don’t touch them. If you do, you can be burned. Don’t run the engine if there is a leak. If you run the engine, it could lose all coolant. That could cause an engine fire, and you could be burned. Get any leak fixed before you drive the vehicle.

NOTICE: Engine damage from running your engine without coolant isn’t covered by your warranty.

If there s e e m to be no leak. start the engine again. See if the fan speed increases when idle speed is doubled by pushing the accelerator pedal down. If it doesn’t, your vehicle needs service. Turn off the engine.

How to Add Coolant to the Coolant Recovery Tank If you haven’t found a problem yet, but the coolant level isn’t at or above the COLD mark, add a SO/SO mixture of c.lea12 water (preferably distilled) and a proper antifreeze at the coolant recovery tank. (See “Engine Coolant” in the Index for more information about the proper coolant mix.)

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NOTICE: In cold weather, water can freeze and crack the engine, radiator, heater core and other parts. Use the recommended coolant.

5-14

When the coolant in the coolant recovery tank is at or above the COLD mark. start your vehicle. If the overheat warning continues, there’s one more thing you can try. You can add the proper coolant mix directly to the radiator, but be sure the cooling system is cool before you do it.

A CAUTION:

Steam and scalding liquids from a hot cooling system can blow out and burn you badly. They are under pressure, and turn the radiator pressure cap - even a little - they can come out at high speed. Never turn the cap when the cooling system, including the radiator pressure cap, is hot. Wait for the cooling system and radiator pressure cap to cool if you ever have to turn the pressure cap.

if you

5- 15

How to Add Coolant to the Radiator r

1.

You can remove the radiator pressure cap when the cooling system, including the radiator pressure cap and upper radiator hose, is no longer hot. Turn the pressure cap slowly to the left until it first stops. (Don't press down while turning the pressure cap.) If you hear a hiss, wait for that to stop. A hiss means there is still some pressure left.

:_.

.w

2. Then keep turning the pressure cap, but now push down as you turn it. Remove the pressure cap.

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3. Fill the radiator with the proper mix, up to the base of the filler neck.

4. Then fill the

coolant recovery tank to the COLD mark.

5. Put the cap back

on the coolant recovery tank, but leave the radiator pressure cap off.

5-17

I L

F

6. Start the engine

and let it run until you can feel the upper radiator hose getting hot. Watch out for the engine fan(s).

7. By this time the coolant level inside the radiator filler neck may be lower. If the level is lower, add more of the proper mix through the filler neck until the level reaches the base of the filler neck.

I _

8. Then replace the pressure cap. At any time during this procedure if

coolant begins to flow out of the filler neck, reinstall the pressure cap. Be sure the arrows on the pressure cap line up like this.

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Cooling System - Diesel Engines

When you decide it‘s safe to lift the hood, here’s what you’ll see: A. Coolant surge tank pressure cap B. Engine fan(s)

C. Radiator A CAUTION:

If your vehicle has air conditioning, the auxiliary electric fan under the hood can start up even when the engine is not running and can injure you. Keep hands, clothing and tools away from any underhood electric fan.

If the coolant inside the coolant surge tank is boiling, don’t do anything else until it cools down.

The coolant level should be at or above the COLD mark. If it isn’t, you may have a leak in the radiator hoses, heater hoses, radiator, water pump or somewhere else in the cooling system.

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I A CAUTION:

Heater and radiator hoses, and other engine parts, can be very hot. Don’t touch them. If you do, you can be burned. Don’t run the engine if there is a leak. If you run the engine, it could lose all coolant. That could cause an engine fire, and you could be burned. Get any leak fixed before you drive the vehicle.

I NOTICE:

Engine damage from running your engine without coolant isn’t covered by your warranty.

If there seems to be no leak, start the engine again. See if the fan speed increases when idle speed is doubled by pushing the accelerator pedal down. If it doesn’t, your vehicle needs service. Turn off the engine. How to Add Coolant to the Coolant Surge Tank

I NOTICE:

The diesel engine has a specific coolant fill procedure. Failure to follow this procedure could cause your engine to overheat and be severely damaged.

If you haven’t found a problem yet, but the coolant level isn’t at the COLD mark, add a 50/50 mixture of cleun water (preferably distilled) and a proper antifreeze at the coolant surge tank, but be sure the cooling system, including the coolant surge tank pressure cap, is cool before you do it. (See “Engine Coolant” in the Index for more information about the proper coolant mix.)

5-20

A CAUTION:

Steam and scalding liquids from a hot cooling system can blow out and burn you badly. They are under pressure, and if you turn the coolant surge tank pressure cap - even a little - they can come out at high speed. Never turn the cap when the cooling system, including the coolant surge tank pressure cap, is hot.

’ Wait for the cooling system and coolant surge tank pressure cap

to cool if you ever have to turn the pressure cap.

A CAUTION:

Adding only plain water to your cooling system can be dangerous. Plain water, or some other liquid like alcohol, can boil before the proper coolant mix will. Your vehicle’s coolant warning system is set for the proper coolant mix. With plain water or the wrong mix, your engine could get too hot but you wouldn’t get the overheat warning. Your engine could catch fire and you or others could be burned. Use a 50/50 mix of clean water and a proper antifreeze.

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NOTICE: In cold weather, water can freeze and crack the engine, radiator, heater core and other parts. So use the recommended coolant.

A CAUTION:

You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol and it will burn if the engine parts are hot enough. Don't spill coolant on

a hot engine.

1. You can remove the coolant surge tank pressure cap when the cooling

system, including the coolant surge tank pressure cap and upper radiator hose, is no longer hot. Turn the pressure cap slowly to the left until it first stops. (Don't press down while turning the pressure cap.) If you hear a hiss, wait for that to stop. A hiss means there is still some pressure left.

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2. Then keep

turning the cap, but now push down as you turn it. Remove the pressure cap.

3. After the engine cools, open the air bleed valve on the thermostat housing.

A CAUTION:

You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol, and parts are hot enough. Don't spill coolant on a hot engine.

it will burn if the engine

4. Fill with the proper mix. Add coolant until you see a steady stream of

coolant coming from the bleed valve.

5. Close the bleed valve. 6. Rinse or wipe the spilled coolant from the engine and compartment.

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7. Then fill the coolant surg,e tank with the proper mix. up to the COLD mark.

8. With the coolant surge tank pressure cap off, start the engine and let it

run until you can feel the upper radiator hose getting hot. Watch out for the engine fan(s). By this time, the coolant level inside the coolant surge tank may be lower. If the level is lower, add more of the proper mix to the coolant surge tank until the level reaches the COLD mark.

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Engine Fan Noise Your vehicle has a clutched engine cooling fan. When the clutch is engaged, the fan spins faster to provide more air to cool the engine. In most every day driving conditions the fan is spinning slower and the clutch is not fully engaged. This improves fuel economy and reduces fan noise. Under heavy vehicle loading, trailer towing and/or high outside temperatures, the fan speed increases as the clutch more fully engages. So you may hear an increase in fan noise. This is normal and should not be mistaken as the transmission slipping or making extra shifts. It is merely the cooling system functioning properly. The fan will slow down when additional cooling is not required and the clutch partially disengages. You may also hear this fan noise when you start the engine. It will go away as the fan clutch partially disengages. If a Tire Goes Flat It’s unusual for a tire to “blow out” while you’re driving, especially if you maintain your tires properly. If air goes out of a tire, it’s much more likely to leak out slowly. But if you should ever have a “blowout,” here are a few tips about what to expect and what to do: If a front tire fails, the flat tire will create a drag that pulls the vehicle toward that side. Take your foot off the accelerator pedal and grip the steering wheel firmly, Steer to maintain lane position, then gently brake to a stop well out of the traffic lane. A rear blowout, particularly on a curve, acts much like a skid and may require the same correction you’d use in a skid. In any rear blowout, remove your foot from the accelerator pedal. Get the vehicle under control by steering the way you want the vehicle to go. It may be very bumpy and noisy, but you can still steer. Gently brake to a stop, well off the road if possible. If a tire goes flat, the next part shows how to use your jacking equipment to change a flat tire safely.

5-25

Changing a Flat Tire If a tire goes flat, avoid further tire and wheel damage by driving slowly to a level place. Turn on your hazard warning flashers.

A. Flat Tire B. Blocked Tire

The following steps will tell you how to use the jack and change a tire. The equipment you’ll need is behind the passenger’s seat. Turn the wing nut counterclockwise and remove the jack cover, if there is one. Your spare tire is stowed under the truck bed, at the rear.

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Jack and Jacking Tool Storage - Two and Four Door Models

1. Nut 2. Jack 3. Jack Handle Extension 4. Wheel Wrench Jack and Jacking Tool Storage - Extended Cab Models

5. Jack and Tool Storage Box 6. Ratchet 7. Jack Handle 8. Tool Retainer

1. Nut 2. Jack and Tool Cover 3. Jack Handle Extension 4. Tool Retainer

5. Jack and Tool Storage Box 6. Ratchet 7. Wheel Wrench 8. Jack 9. Jack Handle

5-27

Jack and Jacking Tool Storage - Chassis Cab Models Jacking Tool Storage - Chassis Cab Models

-1 -1

3 3

1. Nut 2. Jack Handle Extension 3. Wheel Wrench 4. Jack and Tool Storage Box

5. Ratchet 6. Jack Handle 7. Tool Retainer 8, Jack

To Remove the Spare Tire The spare tire, if you have one, is full size like the other tires on your vehicle.

5-28

Spare Tire Stowage - Under-Body Carrier

I . Hoist Assembly 2. Ratchet 3. Wheel Wrench 4. Hoist Shaft

5. Valve Stem, Pointed Down 6. Spare Tire 7. Retainer 8. Hoist Cable

The spare tire is stowed under the vehicle in an under-body carrier. Remember. never remove or restow a tire from an under-body carrier while the vehicle is supported only by a jack. If you have a chassis cab, refer to the information from the body supplier/installer for the location of your spare tire.

5-29

UP Marking

DOWN Marking

One side of the ratchet has an UP marking. The other side has a DOWN marking.

Attach the ratchet to the wheel wrench with the DOWN marking facing you.

Put the other end of the wheel wrench through the rear bumper access hole, located at the passenger side edge of the license plate. Be sure the wheel wrench connects into the hoist shaft.

5-30

Turn the ratchet counterclockwise to lower- the spare tire. Keep turning the ratchet until the spare tire can be pulled o u t from under the vehicle.

When the tire h a s been lowered. till the retainer at the end o f the cable and pull it through the wheel opening.

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Changing the Tire

Start with the jack, the jack handle and the ratchet. If the flat tire is on the rear of the vehicle, you’ll need the jack handle extensions also.

Attach the jack handle (and jack handle extension, if needed) to the jack.

With the U p marking on the ratchet facing you, rotate the ratchet clockwise. That will lift the jack head a little.

Before you start, put the spare tire near the flat tire. Remove the wheel trim and loosen the wheel nuts. The next part wi!l show you how to do these things properly.

5-32

Kemoving Wheel Trim

If your vehicle has wheel nut caps, use the wheel wrench and ratchet t o remove them. Turn the wheel wrench counterclockwise. with DOWN facing you, to remove the wheel nut caps. Then take off the hub cap.

If the wheel also has a trim ring. use the wheel wrench to pry along the edge and remove it.

If the wheel has a smooth center piece or a center piece with recessed nuts, place the wheel wrench in the slot on the wheel and gently pry out.

5-33

Now, use the ratchet and wheel wrench to loosen all the wheel nuts. Turn the wheel wrench counterclockwise, with DOWN facing you, to loosen the wheel nuts. Don’t remove the wheel nuts yet.

If the flat tire is on the rear of the vehicle, put the jack handle extension on the jack handle. Position the jack under the vehicle.

1 A CAUTION:

Getting under a vehicle when it is jacked up is dangerous. If the vehicle slips off the jack, you could be badly injured or killed. Never get under a vehicle when it is supported only by a jack.

NOTICE: Raising your vehicle with the jack improperly positioned will damage the vehicle or may allow the vehicle to fall off the jack. Be sure to fit the jack lift head into the proper location before raising your vehicle.

5-34

Front rosluon

Rear Position

With UP on the ratchet facing you, raise the vehicle by rotating the ratchet and wheel wrench clockwise. Raise the vehicle far enough off the ground so there is enough room for the spare tire to fit.

Remove all the wheel nuts and take off the flat tire,

A CAUTION:

Rust or dirt on the wheel, or on the parts to which it is fastened, can make the wheel nuts become loose after a time. The wheel could come off and cause an accident. When you change a wheel, remove any rust or dirt from the places where the wheel attaches to the vehicle. In an emergency, you can use a cloth or a paper towel to do this; but be sure to use a scraper or wire brush later, if you need to, to get all the rust or dirt off.

5-35

Remove any rust or dirt from the wheel bolts, mounting surfaces and spare wheel. Place the spare on the wheel mounting surface.

A CAUTION:

Never use oil or grease on studs or nuts. If you do, the nuts might come loose. Your wheel could fall off, causing a serious accident.

Replace the wheel nuts with the rounded end of the nuts toward the wheel.

Tighten each wheel nut by hand until the wheel is held against the hub.

Front Position

Rear Position

Lower the vehicle by rotating the ratchet and wheel wrench counterclockwise. Lower the jack completely.

5-36

Tighten Clockwise

Tightening Sequence

4 0

Tighten the nuts firmly in a criss-cross sequence as shown. Rotate the wheel wrench clockwise.

A CAUTION:

Incorrect wheel nuts or improperly tightened wheel nuts can cause the wheel to become loose and even come off. This could lead to an accident. Be sure to use the correct wheel nuts. If you have to replace them, be sure to get the right kind. Stop somewhere as soon as you can and have the nuts tightened with a torque wrench to the proper torque.

For proper torque, see “Wheel Nut Torque” in the Index. Put the wheel trim back on. For vehicles with plastic wheel nut caps, tighten the caps until they are finger tight, then tighten them an additional one-half turn with the ratchet and wheel wrench. Remove any wheel blocks. Remember, the jack, jacking equipment and tire must be properly stored in their original storage position before you begin driving again. The next part, “Storing the Tire and Jack,” will show you how.

5-37

I A ,CAUTION:

Storing a jack, a tire or other equipment in the passenger compartment of the vehicle could cause injury. In a sudden stop or collision, loose equipment could strike someone. Store all these in the proper place.

Stowing the Tire - Under-Body Carrier Stow the flat tire under the r w r of the vehicle in spare tire carrier. To stow the flat tire:

1 .

A I

3.

4.

5.

Put the tire on the ground a t the rear of the vehicle with the valve stern pointed down. Pull the wheel retainer through thc wheel opening. Attach the ratchet t o the urheel n'rench with the UP marking Facing you. Put the other end of the whcel wrench through the rcar bumper access hole, located at the passenger side edge of the license plate. Be sure the wheel wrench connects into the hoist shaft. Turn the ratchet clockwise to raise the tire. Keep turning the ratchet until the tire is all the way up. You will hear two "clicks" when the tire is secure. Pull on the tire t o nuke sure it is tightly secured.

Stowing the Jack and Jacking Tools Return the jack, ratchet, wheel wrench and jack extensions to their location behind the passenger's seat. Stow thc jack and jacking tools as shown in the illustrations earlier in this part. Secure the items and replace the jack cover, if there is one.

5-38

If You’re Stuck: In Sand, Mud, Ice or Snow What you don’t want to do when your vehicle is stuck is to spin your wheels too fast. The method known as ”rocking” can help you get out when you’re stuck, but you nlust use caution.

A CAUTION:

If you let your tires spin at high speed, they can explode and you or others could be injured. And, the transmission or other parts of the vehicle can overheat. That could cause an engine compartment fire or other damage. When you’re stuck, spin the wheels as little as possible. Don’t spin the wheels above 35 mph (55 km/h) as shown on the speedometer.

I NOTICE:

Spinning your wheels can destroy parts of your vehicle as well as the tires. If you spin the wheels too fast while shifting your transmission back and forth, you can destroy your transmission.

For information about using tire chains on your vehicle, see “Tire Chains” in the Index. Rocking your vehicle to get it out: First. turn your steering wheel left and right. That will clear the area around your front wheels. Then shift back and forth between REVERSE (R) and a forward gear (or with a manual transmission, between FIRST (1 ) or SECOND (2) gear and REVERSE), spinning the wheels as little as possible. Release the accelerator pedal while you shift, and press lightly on the accelerator pedal when the transmission is in gear. If that doesn’t get you out after a few tries, you may need to be towed out. Or, you can use your recovery hooks, if your vehicle has them. If you do need to be towed out. see “Towing Your Vehicle” in the Index.

5-39

Using the Recovery Hooks

Your vehicle may be equipped with recovery hooks. The recovery hooks are provided at the front of your vehicle. You may need to use them if you're stuck off-road and need to be pulled to some place where you can continue driving.

I A CAUTION:

The recovery hooks, when used, are under a lot of force. Always pull the vehicle straight out. Never pull on the hooks at a sideways angle. The hooks could break off and you or others could be injured from the chain or cable snapping back.

5-40

NOTICE: Never use the recovery hooks to tow the vehicle. Your vehicle could be damaged and it would not be covered by warranty.

5-41

Notes

5-42

Service & Appearance Care

Section

Here you will find information about the care of your vehicle. This section begins with service and fuel information, and then it shows how to check important fluid and lubricant levels. There is also technical information about your vehicle, and a part devoted to its appearance care. Service Your GM dealer knows your vehicle best and wants you to be happy with it. We hope you’ll go to your dealer for all your service needs. You’ll get genuine GM parts and GM-trained and supported service people. We hope you‘ll want to keep your GM vehicle all GM. Genuine GM parts have one of these marks:

Doing Your Own Service Work If you want to do some of your own service work, you’ll want to get the proper GM Service Manual. It tells you much more about how to service your vehicle than this manual can. To order the proper service manual, see “Service Publications” in the Index.

6-1

You should keep a record with all parts receipts and list the mileage and the date of any service work you perform. See “Maintenance Record” in the Index.

A CAUTION:

You can be injured if you try to do service work on a vehicle without knowing enough about it,

Be sure you have sufficient knowledge, experience, and the proper replacement parts and tools before you attempt any vehicle maintenance task. Be sure to use the proper nuts, bolts and other fasteners, “English” and “metric” fasteners can be easily confused. If you use the wrong fasteners, parts can later break or fall off. You could be hurt.

NOTICE: If you try to do your own service work without knowing enough about it, your vehicle could be damaged.

Fuel (Gasoline Engine) If your vehicle has a diesel engine, see “Diesel Fuel Requirements and Fuel System” in this Section. For vehicles with gasoline engines, please read this. Use regular unleaded gasoline rated at 87 octane or higher. It should meet specifications ASTM D48 14 in the United States and CGSB 3.5-92 in Canada. These fuels should have the proper additives, so you should not have to add anything to the fuel. In the United States and Canada, it’s easy to be sure you get the right kind of gasoline (unleaded). You’ll see UNLEADED right on the pump. And only unleaded nozzles will fit into your vehicle’s filler neck. Be sure the posted octane is at least 87. If the octane is less than 87, you may get a heavy knocking noise when you drive. If it’s bad enough, it can damage your engine. If you’re using fuel rated at 87 octane or higher and you still hear heavy knocking, your engine needs service. But don’t worry if you hear a little pinging noise when you’re accelerating or driving up a hill. That’s normal and you don’t have to buy a higher octane fuel to get rid of pinging. It’s the heavy, constant knock that means you have a problem.

6-2

What about gasoline with blending materials that contain oxygen (oxygenates), such as MTBE or alcohol? MTBE is “methyl tertiary-butyl ether.” Fuel that is no more than 15% MTBE is fine for your vehicle. Ethanol is ethyl or grain alcohol. Properly-blended fuel that is no more than 10% ethanol is fine for your vehicle. Methanol is methyl or wood alcohol.

NOTICE: Fuel that is more than 5% methanol is bad for your vehicle. Don’t use it. It can corrode metal parts in your fuel system and also damage plastic and rubber parts. That damage wouldn’t be covered under your warranty. And even at 5% or less, there to must be “cosolvents” and corrosion preventers in this fuel help avoid these problems.

Gasolines for Cleaner Air Your use of gasoline with deposit control additives will help prevent deposits from forming in your engine and fuel system. That helps keep your engine in tune and your emission control system working properly. It’s good for your vehicle, and you’ll be doing your part for cleaner air. Many gasolines are now blended with oxygenates. General Motors recommends that you use gasolines with these blending materials, such as MTBE and ethanol. By doing so, you can help clean the air, especially in those parts of the country that have high carbon monoxide levels. In addition, some gasoline suppliers are now producing reformulated gasolines. These gasolines are specially designed to reduce vehicle emissions. General Motors recommends that you use reformulated gasoline. By doing so, you can help clean the air, especially in those parts of the country that have high ozone levels. You should ask your service station operators if their gasolines contain deposit control additives and oxygenates, and if they have been reformulated to reduce vehicle emissions. Diesel Fuel Requirements and Fuel Sysrem Some states and provinces have restrictions on the purchase of diesel fuel for light-duty vehicles and require you to buy permits or pay special taxes. Some of these restrictions apply only to residents, and others apply to both residents and visitors. These restrictions can change. To learn the current restrictions in any state or province, contact your auto club, the police or other officials.

6-3

Fuel Requirements

NOTICE: Diesel fuel or fuel additives not recommended in this manual could damage your fuel system and engine. Your warranty wouldn’t cover this damage. And:

Diesel fuel that has been mixed with engine oil could damage your engine and emission controls. Always check with your service station operator to make sure his diesel fuel has not been mixed with engine oil. If you ever run out of diesel fuel, it can be difficult to restart your engine. “Running Out of Fuel,” later in this section, tells you how to get it started again. To avoid all this, try never to let your tank get empty.

What Fuel to Use For best results, use Number 2-D diesel fuel year-round (above and below freezing conditionsj as oil companies blend Number 2-D fuel to address climate differences. Number 1-D diesel fuel may be used in very cold temperatures (when it stays below 0°F or -18°C); however, it will produce a power and fuel economy loss. The use of Number I-D diesel fuel in warm or hot climates may result in stalling, poor starting when the engine is hot and may damage the fuel injection system. Diesel fuel may foam when you fill your tank. This can cause the automatic pump nozzle to shut off, even though your tank isn’t full. If this happens, just wait for the foaming to stop and then continue to fill your tank.

A CAUTION:

Heat coming from the engine may cause the fuel to expand and force the fuel out of your tank. If something ignites the fuel, a fire could start and people could be burned. To help avoid this, fill your fuel tank only until the automatic Don’t try to “top it off.”

nozzle shuts off.

6-4

Canadian Fuels Diesel-powered trucks are now equipped with emission control systems that require the use of diesel fuel with low-sulfur (.05% by weight) content. Both low- and higher-sulfur fuels will be available in Canada. Only low-sulfur diesel fuels are available in the United States. It is important that diesel-powered trucks are refueled with low-sulfur fuel. Use of fuels with higher-sulfur content will affect the function of the emission components and may cause reduced performance, excessive smoke and unpleasant odor.

Cold Weather Operation Follow the instructions listed previously under the heading “What Fuel to Use.” If you’re driving in very toold temperatures and can’t get a “winterized” Number 2-D that has been adapted to cold weather or a Number 1-D, you can use one gallon of kerosene for every two gallons of diesel fuel. Once you add the kerosene, run your engine for several minutes so the fuels will mix. Add kerosene only when the temperature falls below 0°F (-1 S”C), because the fuel economy of kerosene isn’t as good as that of diesel fuel.

NOTICE: Never use home heating oil or gasoline in your diesel engine. They can cause engine damage.

In cold weather, your fuel filter may become clogged (waxed). To unclog it, warm the filter to between 32°F and 50°F (OOC to 10°C). You won’t need to replace it. Water in Fuel Sometimes, water can be pumped into your fuel tank along with your diesel fuel. This can happen if a service station doesn’t regularly inspect and clean its fuel tanks, or if it gets contaminated fuel from its suppliers. If this happens, a WATER IN FUEL light will come on. If it does, the excess water must be drained. Your dealer can show you how to do this.

6-5

WATER

IN FUEL

This light also should come on briefly when you start your engine, as a check. If it doesn’t, have it fixed so it will be there to let you know if you ever do get water in your fuel.

If the light comes on at any other time, use this chart.

If you drive when this warning light is on, you can damage your fuel injection system and your engine. If the light comes on right after you refuel, it means water was pumped into your fuel tank. Turn off your engine immediately. Then, have the water drained at once.

“WATER IN FUEL” LIGHT CHART Problem

Action

Light comes on intermittently. Light stays on: 1. At temperatures above freezing.

2. At temperatures below freezing.

3. Immediately after refueling - large amount of water possibly pumped into fuel tank.

Recommended Drain water from fuel filter.

Drain fuel filter immediately. If no water can be drained and light stays on, see your dealer for assistance. Drain fuel filter immediately. If no water can be drained-water may be frozen. Open the air bleed valve to check for fuel pressure. If no fuel pressure is present, replace the fuel filter. Fuel tank purging required. See your dealer for assistance.

6-6

Hesitation or “flat” performance at high speed or during hard acceleration may be an indication of premature fuel filter plugging due to dirty or contaminated fuel. The fidter element may need to be changed if this happens. See your dealer for assistance. To drain water:

1. Stop and park the vehicle in a safe place. Turn off the engine and apply

the parking brake.

2. Remove the fuel tank cap. 3. Place a fuel-resistant container under the filter drain hose.

4. With the engine

off, open the water drain valve 2 to 3 turns. When standing in front of the vehicle, the valve is located on the right side of the thermostat housing.

5. 6. 7.

Start the engine and allow it to idle until clear fuel is observed. Stop the engine and close the water drain valve. Remove the fuel-resistant container and properly dispose of the contaminated fuel. To find out how to properly dispose of contaminated diesel fuel see “What to Do with Used Oil” in the “Engine Engines)” part, later in this section. Install the fuel tank cap.

8. If the WATER IN FUEL light comes on again after driving a short distance or the engine runs rough or been pumped into the fuel tank. The fuel tank should be purged.

large amount of water has probably

Oil (Diesel

stalls-a

6-7

NOTICE: If there is water in your diesel fuel and the weather humid, fungus and bacteria can grow in the damage your fuel system. You'll need a diesel fuel biocide to sterilize your fuel system. Your dealer can advise you if you ever need this. If your fuel tank needs to be purged to remove water, see your dealer or a qualified technician. Improper purging can damage your fuel system.

fuel. They can

is warm or

Running Out of Fuel (Diesel Engines) If the engine stalls and you think that you've run out of fuel, do this:

First, open the fuel filter air bleed valve. Briefly crank the engine and have someone watch the bleed valve. If there is air, then you are probably out of fuel.

To restart your engine:

I . If you're parked on a level surface, add at least two gallons of fuel.

However, if you're parked on a slope, you may need to add up to five gallons of fuel.

2. With the air bleed valve open, turn your ignition key to START for 10

to 15 seconds to crank (but not start) your engine. Wait one minute between intervals of cranking to allow the starter motor to cool. Overheating the starter motor could damage it. Keep doing this until you can just see some clear fuel at the air bleed valve. (If, during this step, the engine starts, turn the ignition off and close the valve before restart.)

6-8

A CAUTION:

Diesel fuel is flammable. It could start a fire if it gets on hot engine parts. You could be burned. Don't let too much fuel flow from the air bleed valve, and wipe up any spilled fuel with a cloth.

3. Close the air bleed valve. 4. Turn the ignition key to START for 10 to 15 seconds at a time until

your engine starts.

Fuel Filter Replacement (Diesel Engines) If you want to change the fuel filter yourself, here's how to do it:

A CAUTION:

Diesel fuel is flammable. It could start a fire if something ignites it, and you could be burned. Don't let it get on hot engine parts, and keep matches or other ignition sources away.

First. drain any water from the filter following the procedure for draining water listed previously. Your vehicle's engine should be off until the end of the following procedure.

1. Apply the parking brake. 2. Take off the fuel tank cap. This releases vacuum in the tank.

3. Unscrew and

remove the ring nut from the top of the filter head.

6-9

4. Lift the element out of the filter head.

5. If there is any dirt

on the element sealing surface of the filter head, clean it off.

6. Line up the

widest slot in the top of the new element with the widest key on then top of the filter head. Push the element in until the mating surfaces touch.

7. 8.

9. 10.

Replace and tighten the ring nut to the top of the filter head With the air bleed valve open, turn your ignition key to START for 10 to 15 seconds. Wait one minute for your starter to cool. Do this until you can see clear fuel coming from the air bleed valve. Close the air bleed valve and replace the fuel cap. Start your engine and let it idle for five minutes. Check your fuel filter and air bleed valve for leaks.

6- 10

Fuels in Foreign Countries (Gasoline Engines) If you plan on driving in another country outside the U.S. or Canada, unleaded fuel may be hard to find. Do not use leaded gasoline. If you use even one tankful, your emission controls won’t work well or at all. With continuous use, spark plugs can get fouled, the exhaust system can corrode, and your engine oil can deteriorate quickly. Your vehicle’s oxygen sensor will be damaged. All of that means costly repairs that wouldn’t be covered by your warranty. To check on fuel availability, ask an auto club, or contact a major oil company that does business in the country where you’ll be driving. You can also write us at the following address for advice. Just tell us where you’re going and give your Vehicle Identification Number (VIN). General Motors Overseas Distribution Corporation, North American Export Sales (NAES) 1908 Colonel Sam Drive Oshawa, Ontario L l H 8P7 Filling Your Tank

The fuel cap is behind a hinged door on the left side of your vehicle.

A CAUTION:

Gasoline vapor is highly flammable. It burns violently, and that if you’re near gasoline can cause very bad injuries. Don’t smoke or refueling your vehicle. Keep sparks, flames, and smoking materials away from gasoline.

6-11

While refueling, hang the cap inside the fuel door.

To take off the cap, turn it slowly to the left (counterclockwise).

A CAUTION:

-~

If you get gasoline on yourself and then something ignites it, you could be badly burned. Gasoline can spray out on you if you 1 open the fuel filler cap too quickly. This spray can happen if

your tank is nearly full, and is more likely in hot weather. Open the fuel filler cap slowly and wait for any “hiss” noise to stop. Then unscrew the cap all the way.

Be careful not to spill gasoline. Clean gasoline from painted surfaces as soon as possible. See “Cleaning the Outside of Your Vehicle” in the Index. When you put the cap back on, turn it to the right until you hear a clicking noise.

1 NOTICE:

If you need a new cap, be sure t.0 get the right type. Your dealer can get one for you. If you get the wrong type, it may not fit or have proper venting, and your fuel tank and emissions system might be damaged.

6- 12

Checking Things Under the Hood Hood Release

To open the hood, first pull the handle inside the vehicle.

Then go to the front of the vehicle and pull up on the secondary hood release, located just to the passenger side of the center of the grill. Lift the hood.

Your vehicle, if it has air conditioning, may have a auxiliary engine fan in addition to the belt driven fan.

6- 13

A CAUTION:

If your vehicle has air conditioning, the auxiliary engine fan under the hood can start up and injure engine is not running. Keep hands, clothing and tools away from any underhood electric fan.

you even when the

A CAUTION:

Things that burn can get on hot engine parts and start These include liquids like gasoline or diesel fuel, brake fluid, windshield washer and other fluids, and plastic rubber. You or others could be burned. Be careful not to drop or spill things that will burn onto a hot engine.

a fire. oil, coolant,

or

Before closing the hood, be sure all filler caps are on properly. Pull down the hood and close it firmly. Cleaning Your Diesel Engine

I NOTICE:

If you spray or pour water or any other liquid on your engine when it is warm or hot, or when it is running, you could cause serious damage to it. If you ever clean the engine, clean it only when it is cold.

Noise Control System The following information relates to compliance with Federal noise emission standards for vehicles with a Gross Vehicle Weight Rating (GVWR) of more than 10,000 pounds (4 536 kilograms). The Maintenance Schedule booklet provides information on maintaining the noise control system to minimize degradation of the noise emission control system during the life of your vehicle. The noise control system warranty is given in your Warranty booklet. These standards apply only to vehicles sold in the United States.

6-14

Tampering With Noise Control System Prohibited Federal law prohibits the following acts or the causing thereof

1. The removal or rendering inoperative by any person, other than for

purposes of maintenance, repair or replacement, of any device or element of design incorporated into any new vehicle for the purpose of noise control, prior to its sale or delivery to the ultimate purchaser or while it is in use; or

2. The use of the vehicle after such device or element of design has been

removed or rendered inoperative by any person.

Among those acts presumed to constitute tampering are the acts listed below. Insulation:

Removal of noise shields or underhood insulation.

Engine:

0 Removal or rendering engine speed governor (if so equipped) inoperative so as to allow engine speed to exceed manufacturer specifications.

Fan and Drive:

Removal of fan clutch (if so equipped) or rendering clutch inoperative.

0 Removal of fan shroud (if so equipped).

Air Intake:

0 Removal of air cleaner silencer.

Reversing air cleaner cover.

Exhaust:

0 Removal of muffler and/or resonator. 0 Removal of exhaust pipes and exhaust pipe clamps.

6- 15

Engine Oil (Gasoline Engines) It’s a good idea to check your engine oil every time you get fuel. In order to get an accurate reading, the oil must be warm and the vehicle must be on level ground.

Turn off the engine and give the oil a few minutes to drain back into the oil pan. If you don’t, the oil dipstick might not show the actual level.

To Check Engine Oil Pull out the dipstick and clean it with a paper towel or cloth, then push it back in all the way. Remove it again, keeping the tip down.

6- 16

When to Add Oil If the oil is at or below the ADD mark, then you’ll need to add some oil. But you must use the right kind. This part explains what kind of oil to use. For crankcase capacity, see ”Capacities and Specifications” in the Index.

NOTICE: Don’t add too much oil. If your engine has so much oil that the oil level gets above the upper mark that shows the proper operating range, your engine could be damaged.

The engine oil filler cap is located on the driver’s side engine valve cover. Just fill it enough to put the level somewhere in the proper operating range. Push the dipstick all the way back in when you’re through.

What Kind of Oil to Use Oils of the proper quality for your vehicle can be identified by looking for the “Starburst” symbol. The “Starburst” symbol indicates that the oil has been certified by the American Petroleum Institute (API), and is prefenced for use in your gasoline engine.

If you change your own oil, be sure you use oil that has the “Starburst” symbol on the front of the oil container. If you have your oil changed for you, be sure the oil put into your engine is American Petroleum Institute certified for gasoline engines.

6- 17

.

You should also use the proper viscosity oil for your vehicle, as shown in the following chart: LIGHT DUTY EMISSIONS - GASOLINE ENGINES

FOR BEST FUEL ECONOMY AND COLD STARTING, SELECT THE LOWEST SAE VISCOSITY GRADE 011 FOR THE EXPECTED TEMPERATURE RANGE.

HOT

WEATHER

LOOK

FOR THIS SYMBOL

r31.

L c,

SAE IOW-30

SAE SW-30 PREFERRED

WEATHER

DO NOT USE SAE 2OW-50 OR ANY OTHER GRADE OIL NOT RECOMMENDED

As shown in the chart, SAE 5W-30 is best for your vehicle. However, you can use SAE IOW-30 if it’s going to be 0°F (-I 8°C) or above. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity oils, such as SAE 2OW-SO.

6-18

HEAVY DUTY EMISSIONS - GASOLINE ENGINES

RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS

FOR BEST FUEL ECONOMY AND COLD STARTING, SELECT THE LOWEST SAE VISCOSITY GRADE OIL FOR THE EXPECTED TEMPERATURE RANGE.

~~~

HOT

WEATHER

LOOK

FOR THIS SYMBOL

SAE 10W-30 PREFERRED above 0°F

(‘1 8°C)

SA€ 5W-30

COLD

WEATHER

00 NOT USE SA€ 2OW-50 OR ANY OTHER GRADE OIL NOT RECOMMENDED

As shown in the chart, SAE 10W-30 is best for your vehicle. However, you can use SAE SW-30 if it’s going to be colder than 60°F (16°C) before your next oil change. When it‘s very cold, you should use SAE 5W-30. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity oils, such as SAE 2OW-50.

6- 19

NOTICE: Use only engine oil with the American Petroleum Institute Certified For Gasoline Engines “Starburst” symbol. Failure to use the proper oil can result in engine damage not covered by your warranty.

GM Goodwrench@ oil (in Canada, GM Engine Oil) meets all the requirements for your vehicle.

Engine Oil Additives Don’t add anything to your oil. Your GM dealer is ready to advise if you think something should be added. When to Change Engine Oil See if any one of these is true for you:

Most trips are less than 5 to 10 miles (8 to 16 km). This is particularly important when outside temperatures are below freezing. Most trips include extensive idling (such as frequent driving in stop and go traffic). Most trips are through dusty areas. You operate your vehicle in dusty areas or off-road frequently. You frequently tow a trailer.

If any one of these is true for your vehicle, then you need to change your oil and filter every 3,000 miles (5 000 km) or 3 months - whichever comes first. Light Duty Emissions: If none of them is true, change the oil and filter every 7,500 miles (12 500 km) or 12 months - whichever comes first. Heavy Duty Emissions: If none of them is true, change the oil and filter every 6,000 miles (10 000 km) or 12 months - whichever comes first.

6-20

Engine Coolant Heater An engine coolant heater can be a big help if you have to park outside in very cold weather, 0°F (-1 8OC) or colder. If your vehicle has this option, see “Engine Coolant Heater’’ in the Index.

What to Do with Used Oil Did you know that used engine oil contains certain elements that may be unhealthy for your skin and could even cause cancer? Don’t let used oil stay on your skin for very long. Clean your skin and nails with soap and water, or a good hand cleaner. Wash or properly throw away clothing or rags containing used engine oil. (See the manufacturer‘s warnings about the use and disposal of oil products.) Used oil can be a real threat to the environment. If you change your own oil, be sure to drain all free-flowing oil from the filter before disposal. Don’t ever dispose of oil by putting it in the trash, pouring it on the ground, into sewers, or into streams or bodies of water. Instead. recycle it by taking it to a place that collects used oil. If you have a problem properly disposing of your used oil, ask your dealer, a service station or a local recycling center for help. Engine Oil (Diesel Engines) It’s a good idea to check your engine oil level every time you get fuel. In order to get an accurate reading, the oil must be warm and the vehicle must be on level ground.

Turn off the engine and give the oil a few minutes to drain back into the oil pan. If you don’t, the oil dipstick might not show the actual level.

6-21

To Check Engine Oil Pull out the dipstick and clean it with a paper towel or a cloth, then push it back in all the way. Remove it again, keeping the tip down.

When to Add Oil If the oil is at or below the ADD line, then you’ll need to add some oil. But you must use the right kind. This part explains what kind of oil to use. For crankcase capacity, see “Capacities and Specifications” in the Index.

I NOTICE:

Don’t add too much oil. If your engine has so much oil that the oil level gets above the proper operating range, your engine could be damaged.

The engine oil filler cap is located on a filler tube at the front of the engine. Just fill it enough to put the level somewhere in the proper operating range. Push the dipstick all the way back in when you’re through.

6-22

What Kind of Oil to Use Look for these two things:

CF-4/SH CF-4/SH is the best oil for your vehicle. However. if you can not find C F 4 S H oil, you may use C F 4 S G or CE/SH or CE/SG oil. These may be listed as shown or in reverse order, for example SHKF-4. Other letters may also be listed, such as SH/CD, CE, C F 4 . These letters show American Petroleum Institute (API) levels of quality.

NOTICE: If you use oils that don’t have these designations, you can cause engine damage which is not covered by your warranty.

6-23

DIESEL ENGINES

RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS

SELECT THE SAE GRADE OIL BASE0 ON THE EXPECTED TEMPERATURE RANGE

BEFORE NEXT OIL CHANGE

WEATHER

HOT - -

:'

I- 100

/c3'

- -+16

+ 60

+ 32

- 3 0

- - -16 - - -29

-20

WEATHER

FOR LOOK THIS @

SYMBOL

- SAE

30

SAE 1 5 W 4 PREFERRED above 0°F

(-1 8°C)

SAE 1OW-30

00 NOT USE SAE 2OW-50 OR ANY OTHER GRADE OIL NOT RECOMMENDED

a SAE 15W-40

As shown in the viscosity chart, SAE 15W-40 is best for your vehicle. However, you can use SAE IOW-30 if it's going to be colder than 32°F (0°C) before your next oil change. When it's very cold, below 0°F (-18"C), you should use SAE low-30 to improve cold starting. Also, SAE 30 may be used at temperatures above freezing, 32°F (0°C). These numbers on the oil container show its viscosity, or thickness. Do not use other viscosity oils such as SAE 10W-40 or SAE 20W-50.

6-24

This doughnut-shaped logo (symbol) is used on most oil containers to help you select the correct oil. You should look for this on the oil container, and use only those oils that display the logo. GM Goodwrench‘ oil (in Canada, GM Engine Oil) meets all the requirements for your vehicle. Engine Oil Additives Don’t add anything to your oil. Your GM dealer is ready to advise if you think something should be added.

When to Change Engine Oil See if any one of these is true for you:

0 Most trips are less than 5 to I O miles (8 to 16 km). This is particularly

important when outside temperatures are below freezing.

0 Most trips include extensive idling (such as frequent driving in stop and

e 00 traffic).

0 You operate your vehicle in dusty areas or off-road frequently. 0 You frequently tow a trailer or use a carrier on top of your vehicle.

If any of these is true for your vehicle, then you need to change your oil and filter every 2,500 miles (4 000 km) or 3 months - whichever comes first. If none of them is true, change the oil and filter every 5,000 miles (8 000 km) or 12 months - whichever comes first. What to Do with Used Oil Did you know that used engine oil contains certain elements that may be unhealthy for your skin and could even cause cancer? Don‘t let used oil stay on your skin for very long. Clean your skin and nails with soap and water, or a good hand cleaner. Wash or properly throw away clothing or rags containing used engine oil. (See the manufacturer’s warnings about the use and disposal of oil products.) Used oil can be a real threat to the environment. If you change your own oil, be sure to drain all free-flowing oil from the filter before disposal. Don’t ever dispose of oil by putting it in the trash, pouring it on the ground, into sewers, or into streams or bodies of water. Instead, recycle it by taking it to a place that collects used oil. If you have a problem properly disposing of your used oil, ask your dealer, a service station or a local recycling center for help.

6-25

Air Cleaner

To avoid the possibility of un-filtered air being drawn into the engine, make sure the air cleaner cover is o n straight and the wing nuts are properly tightened. If there is an arrow on the air cleaner cover, it should point to the front of the engine. Refer to the Maintenance Schedule to determine when to replace the air filter. See “Scheduled Maintenance Services” in the Index.

A CAUTION:

Operating the engine with the air cleaner off can cause you or others to be burned. The air cleaner not only cleans the air, it stops flame if the engjne backfires. If it isn’t there, and the engine backfires, you could be burned. Don’t drive with it off, and be careful working on the engine with the air cleaner off.

I NOTICE:

If the air cleaner is off, a backfire can cause a damaging engine fire. And, dirt can easily get into your engine, which will damage it. Always have the air cleaner in place when you’re driving.

To remove the air cleaner filter on a gasoline engine or a 6.5 liter naturally aspirated diesel engine, turn the wing nuts to the left. Remove the cover and change the filter.

6-26

To remove the air cleaner filter on a 6.5 liter turbocharged diesel engine, first remove the rubber elbow. Remember to observe the caution about turbocharger blades on the rubber elbow.

Then, unhook the cover retaining clips and push the rear of the cover toward the engine.

Automatic Transmission Fluid When to Check and Change A good time to check your automatic transmission fluid level is when the engine oil is changed. Refer to the Maintenance Schedule to determine when to change your fluid. See "Scheduled Maintenance Services'' in the Index.

How to Check Because this operation can be a little difficult, you may choose to have this done at your GM dealer Service Department. If you do it yourself, be sure to follow all the instructions here, or you could get a false reading on the dipstick.

NOTICE: Too much or too little fluid can damage your transmission. Too much can mean that some of the fluid could come out and fall on hot engine parts or exhaust system parts, starting a fire. Be sure to get an accurate reading if you check your transmission fluid.

6-27

Wait at least 30 minutes before checking the transmission fluid level if you have been driving:

When outside temperatures are above 90°F (32°C). At high speed for quite a while. In heavy traffic - especially in hot weather. While pulling a trailer.

To get the right reading. the fluid should be at normal operating temperature, which is 180°F to 200°F (82°C to 93°C). To check transmission fluid hot: Get the vehicle warmed up by driving about 15 miles (24 km) when outside temperatures are above 50°F (10°C). If it's colder than 50°F (lO"C), drive the vehicle in DRIVE (3) until the engine temperature gage moves and then remains steady for ten minutes. Then follow the hot check procedures. To check transmission fluid cold: A cold check is made after the vehicle has been sitting for eight hours or more with the engine off and is used only as a reference. Let the engine run at idle for five minutes if outside temperatures are 50°F (10°C) or more. If it's colder than 50°F (IOOC), you may have to idle the engine longer. Should the fluid level be low during a cold check, you must perform a hot check before adding fluid. This will give you a more accurate reading of the fluid level.

To check the fluid hot or cold

Park your vehicle on a level place. Keep the engine running. With the parking brake applied, place the shift lever in PARK (P). With your foot on the brake pedal, move the shift lever through each gear range, pausing for about three seconds in each range. Then, position the shift lever in PARK (P). Let the engine run at idle for three minutes or more.

6-28

Then, without shutting off the engine, follow these steps:

1. Flip the handle up and then pull out the dipstick and wipe it with a

clean rag or paper towel.

2. Push it back in all the way, wait three seconds and then pull it back out

again.

3. Check both sides of the dipstick, and read the lower level. The fluid level must be in the COLD area for a cold check or in the HOT area or cross-hatched area for a hot check.

4. If the fluid level is in the acceptable range, push the dipstick back in all

the way; then flip the handle down to lock the dipstick

in place.

6-29

How to Add Fluid Refer to the Maintenance Schedule to determine what kind of transmission fluid to use. See “Recommended Fluids and Lubricants” in the Index. Add fluid only after checking the transmission fluid HOT. (A COLD check is used only as a reference.) If the fluid level is low, add only enough of the proper fluid to bring the level up to the HOT area for a hot check. It doesn’t take much fluid, generally less than a int. Don ’t overfill. We recommend you use only fluid labeled DEXRON -111, because fluid with that label is made especially for your automatic transmission. Damage caused by fluid other than DEXRON@-I11 is not covered by your new vehicle warranty.

0 After adding fluid, recheck the fluid level as described under “How to

Check.”

0 When the correct fluid level is obtained, push the dipstick back in all

the way; then flip the handle down to lock the dipstick in place.

Manual Transmission Fluid When to Check A good time to have it checked is when the engine oil is changed. However, the fluid in your manual transmission doesn’t require changing.

How to Check Because this operation can be a little difficult, you may choose to have this. done at your GM dealer Service Department. If you do it yourself, be sure to follow all the instructions here, or you could get a false reading.

NOTICE: Too much or too little fluid can damage your transmission. Too much can mean that some of the fluid could come out and fall on hot engine parts or exhaust system parts, starting a fire. Be sure to get an accurate reading if you check your transmission fluid.

Check the fluid level only when your engine is off, the vehicle is parked on a level place and the transmission is cool enough for you to rest your fingers on the transmission case.

6-30

Then, follow these steps:

1. Remove the filler plug. 2. Check that the lubricant level is up to the bottom of the filler plug hole. 3. If the fluid level is good, install the plug and be sure it is fully seated. If the fluid level is low, add more fluid as described in the next steps.

How to Add Fluid Here’s how to add fluid. Refer to the Maintenance Schedule to determine what kind of fluid to use. See “Recommended Fluids and Lubricants” in the Index.

1. Remove the filler plug. 2. Add fluid at the filler plug hole. Add only enough fluid to bring the

fluid level up to the bottom of the filler plug hole.

3. Install the filler plug. Be sure the plug is fully seated. Hydraulic Clutch The hydraulic clutch linkage in your vehicle is self-adjusting. A slight amount of play (1/4 inch to 1/2 inch) in the pedal is normal.

6-31

When to Check and What to Use

Refer to the Maintenance Schedule to determine how often you should check the fluid level in your clutch master cylinder reservoir and d for the proper fluid.

See “Owner Checks and Services” and “Recommended Fluids and Lubricants” in the Index.

How to Check The proper fluid should be added if the level does not reach the bottom of the diaphragm when it’s in place in the reservoir. See the instructions on the reservoir cap. Rear Axle When to Check and Change Lubricant Refer to the Maintenance Schedule to determine how often to check the lubricant and when to change it. See ”Scheduled Maintenance Services’‘ in the Index. How to Check Lubricant

If the level is below the bottom of the filler plug hole, you’ll need to add some lubricant. Add enough lubricant to raise the level to the bottom of the filler plug hole.

6-32

What to Use Refer to the Maintenance Schedule to determine what kind of lubricant to use. See “Recommended Fluids and Lubricants” in the Index. C3 (3500 H.D.) Trucks Equipped with Dana Rear Axle Additional rear axle scheduled maintenance is required on 3500 H.D. models equipped with Dana rear axles when they are driven under the following conditions:

0 Extreme loading (at or near GVWR) or trailer towing, and:

Operation above 45 mph for extended periods of time

Vehicles used i n any of these conditions require the rear axle lubricant (SAE 8OW-90 - GL-5) be changed every 3 months or 3,000 miles, whichever comes first. To reduce required maintenance, SAE 75W-140 synthetic gear lubricant may be used. With the use of synthetic SAE 75W-140 lubricant, the fluid change intervals may be increased to 30,000 miles. Before using SAE 75W-140, it is important to drain and flush the axle with clean mineral based (non-synthetic) axle lubricant. Fluid capacity is 4.12 qts. (3.9L). Four- Wheel Drive Most lubricant checks in this section also apply to four-wheel-drive vehicles. However, they have two additional systems that need lubrication.

Transfer Case

When to Check Lubricant Refer to the Maintenance Schedule to determine how often to check the lubricant. See “Periodic Maintenance Inspections” in the Index.

6-33

How to Check Lubricant

If the level is below the bottom of the filler plug hole, you’ll need to add some lubricant. Add enough lubricant to raise the level to the bottom of the filler plug hole.

What to Use Refer to the Maintenance Schedule to determine what kind of lubricant to use. See “Recommended Fluids and Lubricants”

in the Index.

Front Axle

When to Check and Change Lubricant Refer to the Maintenance Schedule to determine how often to check the in lubricant and when to change it. See “Scheduled Maintenance Services” the Index.

How to Check Lubricant

If the level is below the bottom of the filler plug hole, you’ll need to add some lubricant.

6-34

If the differential is at operating temperature (warm), add enough lubricant to raise the level to the bottom of the filler plug hole. If the differential is cold, add enough lubricant to raise the level to 1/2 inch ( 12 mm) below the filler plug hole.

What to Use Refer to the Maintenance Schedule to determine what kind of lubricant to use. See “Recommended Fluids and Lubricants” in the Index. Engine Coolant The following explains your cooling system and how to add coolant when it is low. If you have a problem with engine overheating, see “Engine Overheating” in the Index. The proper coolant for your vehicle will:

Give freezing protection down to -34°F (-37°C).

0 Give boiling protection up to 262°F (128°C).

Protect against rust and corrosion. Help keep the proper engine temperature. Let the warning gages work as they should.

What to Use Use a mixture of one-half cleun water (preferably distilled) and one-half antifreeze that meets “GM Specification 6038-M,” which won’t damage aluminum parts. You can also use a recycled coolant conforming to “GM Specification 6038-M.” Use GM Coolant Supplement (Sealer) with a complete coolant flush and refill. If you use this mixture. you don’t need to add anything else.

A CAUTION:

Adding only plain water to your cooling system can be dangerous. Plain water, or some other liquid like alcohol, can boil before the proper coolant mix will. Your vehicle’s coolant warning system is set for the proper coolant mix. With plain water or the wrong mix, your engine could get too hot but you wouldn’t get the overheat warning. Your engine could catch fire and you or others could be burned. Use a 50/50 mix of clean water and a proper antifreeze.

6-35

NOTICE: If you use an improper coolant mix, your engine could overheat and be badly damaged. The repair cost wouldn’t be covered by your warranty. Too much water in the mix can freeze and crack the engine, radiator, heater core and other parts.

Some conditions. such as air trapped in the cooling system. can affect the coolant level i n thc radiator. Check the coolant level when the engine is cold and follow the steps under “Adding Coolant“ for the proper way to add coolant. If you have to add coolant more than lour timcs a ycar, have your dealer check your cooling system.

NOTICE: If you use the proper coolant, you don’t have to add extra inhibitors or additives which claim to improve the system. These can be harmful.

Adding Coolant - Gasoline Engine

The coolant reco\wy tank is located on the passenger side a t the rear comer of the engine compartment.

To Check Coolant When your engine is cold, the coolant level should be at the COLD mark, or a little higher. When your engine is warm, the level should be up to the HOT mark, or a little higher.

6-36

To Add Coolant If you need more coolant, add the proper mix at the coolant recovery tank.

A CAUTION:

a r n i n g the radiator pressure cap when the engine and radiator are hot can allow steam and scalding liquids to blow out and burn you badly. With the coolant recovery tank, you will almost never have to add coolant at the radiator. Never turn the radiator pressure cap - even a little - when the engine and radiator are hot.

Add coolant mix at the recovery tank, but be careful not to spill it.

A CAUTION:

You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol, and it will burn if the engine parts are hot enough. Don’t spill coolant on a hot engine.

Adding Coolani - Diesel Engine

The coolant surge tank is located on the passenger side at the rear corner of the engine compartment.

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To Check Coolant

A CAUTION:

Turning the surge tank pressure cap when the engine and radiator are hot can allow steam and scalding liquids to blow out and burn you badly. Never turn the surge tank pressure cap - even a little - when the engine and radiator are hot.

When your engine is cold, the coolant level should be at the COLD mark, or a little higher.

If this light comes on, it means you’re low on engine coolant.

To Add Coolant If you need more coolant, add the proper mix ut the surge t m k , but only when the engine is cool. If the surge tank is empty, see “Engine Overheating” in the Index for the proper fill procedure.

A CAUTION:

You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol, and it will burn if the engine parts are hot enough. Don’t spill coolant on a hot engine.

When replacing the pressure cap, make sure it is tight.

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Radiator Pressure Cap - Gasoline Engine

The radiator pressure cap must be tightly installed with the arrows on the cap lined up with the overflow tube on the radiator filler neck.

NOTICE: Your radiator cap is a 15 psi (105 kPa) pressure-type cap and must be tightly installed to prevent coolant loss and possible engine damage from overheating. Be sure the arrows on the cap line up with the overflow tube on the radiator Surge Tank Pressure Cap - Diesel Engine The surge tank pressure cap must be tightly installed with the arrows on the cap lined up with the top tube of the coolant surge tank.

filler neck.

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NOTICE: Your surge tank pressure cap is a unique 15 psi (105 kPa) pressure-type cap for use with surge tank cooling systems only. It must be tightly installed to prevent coolant loss and possible engine damage from overheating. Be sure the arrows on the cap line up with the top tube of the coolant surge tank.

Thermostat Engine coolant temperature is controlled by a thermostat in the engine coolant system. The thermostat stops the radiator until the coolant reaches a preset temperature. When you replace your thermostat, an AC@ thermostat is recommended. Power Steering Fluid

flow of coolant through the

How To Check Power Steering Fluid When the engine compartment is cool, unscrew the cap and wipe the dipstick with a clean rag. Replace the cap and completely tighten remove the cap again and look at the fluid level on the dipstick. The level should be at the FULL COLD mark. Add enough fluid to bring the level up to the mark. A fluid loss in this system could indicate a problem. Have the system inspected and repaired.

it. Then

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What to Add Refer to the Maintenance Schedule to determine what kind of' tluid to use See "Recommended Fluids and Lubricants" i n the Index.

NOTICE: When adding power steering fluid or making a complete fluid change, always use the proper fluid. Failure to use fluid can cause leaks and damage hoses and seals.

the proper

Hydro-Boost Brake System (Hydraulic Pump) The power steering pump is also used as the Hydro-boost pump. Refer to "Power Steering System'' in this section when checking fluid level or adding fluid. Windshield Washer Fluid

What to Use When you need windshield washer fluid, be sure to read the manuhcturer's instructions before use. If you will be operating your vehicle in an area where the temperature m a y fall below freezing, use a fluid that has sufficient protection against freezing.

To Add

Open the cap labeled WASHER FLUID ONLY. Add washer fluid until the tank is full.

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NOTICE:

When using concentrated washer fluid, follow the manufacturer’s instructions for adding water. Don’t mix water with ready-to-use washer fluid. Water can cause the solution to freeze and damage your washer fluid tank and other parts of the washer system. Also, water doesn’t clean as well as washer fluid.

0 Fill your washer fluid tank only 3/4 full when it’s very cold.

if it is This allows for expansion, which could damage the tank completely full.

0 Don’t use radiator antifreeze in your windshield washer. It

can damage your washer system and paint.

Brake Master Cylinder Your brake master cylinder is here. It is filled with DOT-3 brake fluid.

There are only two reasons why the brake fluid level in your master cylinder might go down. The first is that the brake fluid goes down to an acceptable level during normal brake lining wear. When new linings are put in, the fluid level goes back up. The other reason is that fluid is leaking out of the brake system. If it is, you should have your brake system fixed, since a leak means that sooner or later your brakes won’t work well, or won’t work at all. So, it isn‘t a good idea to “top off’ your brake fluid. Adding brake fluid won’t correct a leak. If you add fluid when your linings are worn, then you’ll have too much fluid when you get new brake linings. You should add

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(or remove) brake fluid, as necessary, only when work is done on the brake

hydraulic system. A CAUTION:

If you have too much brake fluid, it can spill on the engine. The fluid will burn if the engine is hot enough. You or others could be burned, and your vehicle could be damaged. Add brake fluid only when work is done on the brake hydraulic system.

Refer to the Maintenance Schedule to determine when to check your brake fluid. See “Periodic Maintenance Inspections” in the Index.

To Check Brake Fluid You can check the brake fluid without taking off the cap. Just look at the windows on the brake fluid reservoir. The fluid levels should be above MIN. If they aren’t, have your brake system checked to see if there is a leak. After work is done on the brake hydraulic system, make sure the levels are above MIN and below the top of each window.

What to Add When you do need brake fluid, use only DOT-3 brake fluid - such as (GM Part No. 1052535). Use new brake fluid from a Delco Supreme 11 sealed container only, and always clean the brake fluid reservoir cap before removing it.

NOTICE:

Don’t let someone put in the wrong kind of fluid. For example, just a few drops of mineral-based oil, such as engine oil, in your brake system can damage brake system parts so badly that they’ll have to be replaced. Brake fluid can damage paint, so be careful not to spill brake fluid on your vehicle. If you do, wash it off immediately. See “Appearance Care” in the Index.

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Brake Wear Your vehicle has front disc brakes and rear drum brakes. If you have a C 3500 HD model, it has four-wheel disc brakes. Disc brake pads have built-in wear indicators that make a high-pitched warning sound when the brake pads are worn and new pads are needed. The sound may come and go or be heard all the time your vehicle is moving (except when you are pushing on the brake pedal firmly).

I A CAUTION:

The brake wear warning sound means that sooner or later your brakes won’t work well. That could lead to an accident. When you hear the brake wear warning sound, have your vehicle serviced.

NOTICE: Continuing to drive with worn-out brake pads could result in costly brake repair.

Some driving conditions or climates may cause a brake squeal when the brakes are first applied or lightly applied. This does not mean something is wrong with your brakes. If you have rear drum brakes, they don’t have wear indicators, but if you ever hear a rear brake rubbing noise, have the rear brake linings inspected. Also, the rear brake d r u m should be removed and inspected each time the tires are removed for rotation or changing. When you have the front brakes replaced, have the rear brakes inspected, too. Brake linings should always be replaced as complete axle sets. Brake Pedal Travel See your dealer if the brake pedal does not return to normal height, or if there is a rapid increase in pedal travel. This could be a sign of brake trouble.

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Brake Adjustment Every time you make a brake stop, your disc brakes adjust for wear. If your brake pedal goes down farther than normal, your rear drum brakes may need adjustment. Adjust them by backing up and firmly applying the brakes a few times. Replacing Brake System Parts The braking system on a modeffl VEShicle is complex. Its many parts have to be of top quality and work well together if the vehicle is to have really good braking. Vehicles we design and test have top-quality GM brake parts in them, as your vehicle does when it is new. When you replace parts of your braking system - for example, when your brake linings wear down and you have to have new ones put in - be sure you get new genuine GM replacement parts. If you don't, your brakes may no longer work properly. For example, if someone puts in brake linings that are wrong for your vehicle, the balance between your front and rear brakes can change - for the worse. The braking performance you've come to expect can change in many other ways if someone puts in the wrong replacement brake parts. Front Shock Absorbers The front shock absorbers of your vehicle do many things. They help the vehicle ride smoothly and also control the travel of the suspension system. When the shock absorbers are serviced, any replacement shock absorbers must be the same as the original equipment shock absorbers in both extended length and strength.

I NOTICE:

If you use shock absorbers that are not the same as the original shock absorbers, the shock absorbers or suspension system could be damaged.

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Windshield Wiper Blade Inserts

To replace the windshield wiper blade insert, lift the wiper arm and rotate the blade until it is facing away from the windshield.

Unlatch the end of the insert from the holding clips. Remove the insert and slide a new one in place. Make sure the blade is secured in the clips. Air Conditioning Every now and then have your dealership check your air conditioning system to be sure it has not lost any cooling ability. If you think the system is not working properly, have your dealership check it out as soon as possi bleb The air conditioning will not work when the temperature is below 40°F (4°C). Fluid Leak Check After the vehicle has been parked for a while, inspect the surface under the vehicle for water, oil, fuel or other fluids. Water dripping from the air conditioning system after it has been used is normal. If you notice fuel leaks or fumes, the causes should be found and corrected at once. Lock Cylinders To be sure your locks operate properly, they must be lubricated. Your vehicle’s maintenance schedule will tell you how often to lubricate them. See “Recommended Fluids and Lubricants” in the Index for the proper lubricant to use. You should not use penetrating oils because they could wash out the factory installed lubricant and cause the lock to bind. De-icers which contain alcohol could also wash away the lubricant, so be sure to lubricate the lock after using a de-icer of this type.

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Battery Every new GM vehicle has a Delco Freedom@ battery. You never have to add water to one of these. When it’s time for a new battery, we recommend a Delco Freedom@ battery. Get one that has the replacement number shown on the original battery’s label.

Vehicle Storage If you’re not going to drive your vehicle for 25 days or more. take off the black, negative (-) cable from the battery. This will help keep your battery from running down.

A CAUTION:

Batteries have acid that can burn you and gas that can explode. You can be badly hurt if you aren’t careful. See “Jump Starting’’ in the Index for tips on working around a battery without getting hurt.

Contact your dealer to learn how to prepare your vehicle for longer storage periods. Bulb Replacement Before you replace any bulbs. be sure that a l l the lamps are off and the engine isn’t running.

Sealed Beam Headlamps

I . Remove the four