check engine GMC C-SERIES 1999 Owner's Guide

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6-25 Checking Coolant
Coolant Recovery Tank
(Gasoline Engines
-- Specialty Hood)
Coolant Recovery Tank
(Gasoline Engines
-- Sloped Hood)
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6-28
Power Steering Fluid
See your Maintenance Schedule for when to check your
power steering fluid.
How To Check Power Steering Fluid
Check your power steering fluid only when the engine is
warm. If the engine isn't warm, you probably won't get
an accurate reading.
Vehicles with diesel engines
have a sight glass. If you
can see fluid in the glass,
you have enough.Other models have a cap with a dipstick. If you have
one, unscrew the cap and check the dipstick. It should be
between ADD and FULL (if the engine is warm).
If you need to add some, put in only enough of the
correct fluid to bring the level up to the FULL mark (if
you have the dipstick) or so you can see fluid in the
glass, if you have a sight glass.
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6-30
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.

Fill your washer fluid tank only
three
-quarters full when it's very cold.
This allows for expansion if freezing occurs,
which could damage the tank if it is
completely full.

Don't use engine coolant (antifreeze) in
your windshield washer. It can damage
your washer system and paint.
Brakes
Brake Fluid
If your vehicle has
hydraulic brakes, there's
a brake master cylinder.
The brake master cylinder
reservoir is here. Refer to
the Maintenance Schedule
to determine when to check
your brake fluid.
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6-31
CAUTION:
Don't add brake fluid before you check the level.
If you do, you could get too much brake fluid.
Brake fluid could spill on the hot engine and it
can catch fire. You could be burned and your
vehicle could be damaged.
Checking Brake Fluid
Apply the brake pedal several times with the ignition
off. Then clean one of the reservoir caps and the area
around the cap, and remove it. The fluid level should be
even with the bottom ring of the filler opening.
If it's low, add enough fluid
to fill the reservoir to the
proper level.
What to Add
Use the proper fluid listed in your Maintenance
Schedule. Use new brake fluid from a sealed
container only.
Always clean the brake fluid reservoir cap and the area
around the cap before removing it. This will help keep
dirt from entering the reservoir.
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6-45 Fuel Filter (Diesel Engines)
The ACDelco
fuel filter is located in the component
box. See your Maintenance Schedule for recommended
service intervals.
Primary Fuel Filter and Water Separator
(Option)
If you have a Caterpillar

diesel engine, you may
have this spin
-on filter.
It is in the component box
on the driver's side behind
the fender.
It has a clear plastic drain bowl at the bottom. Check the
drain bowl occasionally for any water or particles. To
drain the bowl, shut off the engine. Then partially open
the drain valve at the bottom of the filter. See ªEngine
Oilº in the Index for proper disposal procedures.
Secondary Fuel Filter and Water
Separator/Heater (Option)
If you have a Caterpillar

diesel engine, you may have
this spin
-on filter and fuel
separator/heater. It is
mounted on the passenger's
side of the engine.
It has a metal drain bowl at the bottom. Occasionally, check
the bowl for any water or particles. To check or drain the
bowl, shut off the engine. Then push up on the spring loaded
drain valve until clear fuel is flowing from the valve. The
particles or water will drain out first. See ªEngine Oilº in the
Index for proper disposal procedures.
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6-46 Automatic Ether Injection System (Option)
If your diesel engine vehicle
has this feature, the ether
cylinder is on the upper
right rear side of the engine
compartment.
To change an empty ether cylinder, follow these steps.
1. Loosen the 5/16 inch screw head on the
cylinder
-to-bracket clamp.
2. Spread the clamp apart.3. Clean any dirt from the neck of the cylinder and the
top of the valve before you take out the cylinder.
4. Check the inside of the valve for any foreign matter.
Clean the valve as necessary.
5. Cover the valve to protect it from dirt and take out
the cylinder.
6. Install a new gasket whenever you take out the
cylinder. Use only one gasket and spread a light film
of clean oil on it before installation.
7. Put in the new cylinder. Turn it clockwise until it just
starts to contact the gasket.
8. Tighten the cylinder another half turn (180 degrees).
Don't over
-tighten.
9. Retighten the cylinder clamp.
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6-48 Muffler/Catalytic Converter Assemblies
(Diesel Engines)
Some vehicles equipped with a Caterpillar
diesel engine
utilize a catalytic converter
-muffler assembly. If your
vehicle is equipped with a catalytic converter
-muffler,
some special procedures may need to be followed when
servicing your vehicle. Consult your GM Truck dealer
who is an authorized Caterpillar

engine dealer
for service.
To determine your vehicle's muffler type, examine the
muffler outer housing. If your system is a catalytic
converter
-muffler type, the housing will be stamped
with the CAT logo.
Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your tire warranty and where to obtain service, see
your GM Warranty booklet for details.
CAUTION:
Poorly maintained and improperly used tires
are dangerous.

Overloading your tires can cause
overheating as a result of too much friction.
You could have an air
-out and a serious
accident. See ªLoading Your Vehicleº in
the Index.

Underinflated tires pose the same danger as
overloaded tires. The resulting accident
could cause serious injury. Check all tires
frequently to maintain the recommended
pressure. Tire pressure should be checked
when your tires are cold.

Overinflated tires are more likely to be cut,
punctured or broken by a sudden
impact
-- such as when you hit a pothole.
Keep tires at the recommended pressure.

Worn, old tires can cause accidents. If your
tread is badly worn, or if your tires have
been damaged, replace them.
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6-68
Electrical System
Add-On Electrical Equipment
NOTICE:
Don't add anything electrical to your vehicle
unless you check with your dealer first. Some
electrical equipment can damage your vehicle
and the damage wouldn't be covered by your
warranty. Some add
-on electrical equipment can
keep other components from working as
they should.
Headlamp Wiring
The headlamp wiring is protected by a circuit breaker in
the light switch. An electrical overload will cause the
lights to go on and off, or in some cases to remain off.
If this happens, have your headlamp wiring checked
right away.
Windshield Wiper Fuses
The windshield wiper motor is protected by a circuit
breaker inside the motor and a circuit breaker in the fuse
block. If the motor overheats, the wipers will stop until
the motor cools. If the overload is caused by an
electrical problem, be sure to get it fixed.
Fusible Links
A fusible link is a short piece of wire several gage sizes
smaller than the circuit it protects. It will melt in an
overload situation, opening the circuit.
Your starter relay and other circuits have these fusible
links. The size is printed on the insulation. If the insulation
is burned beyond recognition, consult your GM dealer for
the proper size. Replace a fusible link with one of the
same size and insulation type. Fusible link insulation is a
special purpose high
-temperature material.
The hydraulic brake booster motor feed circuit and
starter relay circuit are protected by a fusible link.
Vehicles with a diesel engine have a fusible link for the
intake heater feed circuit. Vehicles equipped with an
electronically controlled diesel engine also have a
fusible link for the engine control unit.
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6-72
Maxi-Fuse Block
When a circuit goes out, first check the instrument panel
circuit breaker block. If no circuit breakers are out there,
the problem could in the maxi
-fuse block.
This block uses blade
-type fuses. It's on the upper
passenger side of the engine compartment at the rear.
To access the maxi-fuse block, gently squeeze both
sides of the cover to unlatch the tabs at the top. Then,
unsnap both attachments at the bottom and remove
the cover.
Power is fed through these fuses to devices such as the
headlamp switch, ignition switch feed circuits and the
auxiliary brake pump (hydraulic brake vehicles).
Be sure to replace maxi
-fuses with maxi-fuses of the
same rating. Do not use maxi
-fuses of higher amperage
than those indicated on the maxi
-fuse block.
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6-75
Extending the recommended oil change interval requires
the use of an infrared oil analysis program which shows
the condition of the oil and its additives. For more
information, consult your GM Truck dealer, who is an
authorized Caterpillar

engine dealer.
Transmission Capacity
Capacities (volumes) shown are approximate. For
manual transmissions, the correct oil level is to the
bottom of the fluid fill plug opening. The oil capacity
will vary, due to the angle of the transmission, with the
vehicle. For automatic transmissions, see the Allison
Automatic Transmission Operator's Manual for oil
check and maintenance information.
Manual Transmission Pints (Liters)
RT6609 12.0 (5.7). . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RT6610 12.0 (5.8). . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RTO6610 12.0 (5.8). . . . . . . . . . . . . . . . . . . . . . . . . . . RT6613 16.0 (7.5). . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RT7608LL 19.5 (9.3). . . . . . . . . . . . . . . . . . . . . . . . . .
RT8609 15.0 (7.0). . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FS4205A, FS4205B, FS4205C 12.5 (5.9). . . . . . . . . .
5205A, FS5205C 12.5 (5.9). . . . . . . . . . . . . . . . . . . . .
FS5306 18.0 (8.5). . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FS6305A, FS6305B 19.0 (9.0). . . . . . . . . . . . . . . . . . .
FS6306 19.5 (9.2). . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FS7206 20.0 (9.5). . . . . . . . . . . . . . . . . . . . . . . . . . . . .
T8607B 36.0 (17.0). . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic Transmission Pints (Liters)
AT542 (for oil pan filter change) 30.0 (14.0)*. . . . . . .
AT545 (for oil pan filter change) 40.0 (19.0)*. . . . . . .
MT643 (for oil pan filter change) 13.0 (24.5)*. . . . . .
MT653 (for oil pan filter change) 36.0 (17.0)*. . . . . .
*Add two pints (one liter) when changing spin
-on filter.
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