1999 GMC C-SERIES brake fluid

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7-17 99,000 Miles (165 000 km)

Engine oil and filter service. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(2)(6)
100,000 Miles (166 000 km)

Change power steering fluid (or every 36 months,
whichever occurs first). (13)

Front axle service (or every 36 months, whichever
occurs first). (38)

Rear axle service
-- Eaton, Rockwell, Spicer Axles
(or every 12 months, whichever occurs first). (1)(37)

Exhaust brake service (if equipped). Check for
excessive spindle free play and smooth operation.
Lubricate ball joint cap.

Accelerator control cable replacement (diesel) (or
every 36 months, whichever occurs first). (19)

Air brake service (or every 12 months, or
3,600 hours, whichever occurs first). (44)
150,000 Miles (240 000 km)

Cooling system service (or every 60 months since
last service, whichever occurs first). (3)(35)
200,000 Miles (320 000 km)

Remove, disassemble, clean and inspect the air brake
trailer supply valve (or every 2 years, or 7,200 hours,
whichever occurs first).
250,000 Miles (400 000 km)

Wheel bearings service -- Eaton Axle (oil-filled) (or
every 36 months, whichever occurs first). (2)(23)

Rear axle service
-- Eaton, Rockwell, Spicer Axles
(or every 36 months, whichever occurs first). (2)(37)

Manual transmission fluid replacement (or every
60 months, whichever occurs first).
300,000 Miles (480 000 km)

Remove, disassemble, clean and inspect the air brake
air dryer (or every 3 years, or 10,800 hours,
whichever occurs first). Replace dessicant on
Bendix
-Westinghouse units.
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7-18 Footnotes

= The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to the
completion of the vehicle's useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the maintenance
be recorded.
(1) = If your vehicle has an Allison automatic
transmission, your GM Owner's Manual is
supplemented by an Allison Transmission Operator's
Manual. Always refer to these manuals for related
maintenance services.
(2) = Check the fluid level in the manual transmission.
(3) = An Emission Control Service.
(4) = A Noise Emission Control Device.
(5) = Applies only to vehicles sold in the United States.
(6) = Check fluid level in brake master cylinder, clutch
master cylinder (if equipped), power steering pump,
axle, transmission and hydraulic spring parking brake
pump (if equipped). A low fluid level in the brake
master cylinder can indicate worn brake linings and
should be checked accordingly.(7) = Inspect brake lines and hoses for proper hook
-up,
binding, leaks, cracks, chafing, etc. Inspect disc brake
pads for wear and rotors for surface condition. Check
brake pedal for excessive free play or travel (or every
6 months, whichever occurs first) and have serviced if
needed. Check brakes more often if driving habits and
conditions result in frequent braking.
(8) = Inspect hydraulic parking brake drum and linings
for wear or cracks and check linkage and adjustment.
Check spring brake actuator and pump for leaks.
Note: The spring brake section of the actuator is
non
-serviceable.
(9) = This vehicle has an Engine Oil Life Monitor. This
monitor will show you when to change the engine oil
and filter
-- usually between 3,000 miles (5 000 km) and
7,500 miles (12 500 km) since your last oil change.
Under severe conditions, the indicator may come on
before 3,000 miles (5 000 km). Never drive your vehicle
more than 7,500 miles (12 500 km) or 12 months
without an oil and filter change.
The system won't detect dust in the oil. So if you drive
in a dusty area, be sure to change your oil and filter
every 3,000 miles (5 000 km) or sooner if the Change
Oil Light comes on. Remember to reset the Oil Life
Monitor whenever the oil is changed. For more
information, see ªChange Oil Lightº in the Index.
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7-19
(10) = Check clutch pedal for free travel. Press pedal
by hand until resistance is felt. Free travel should be
maintained at 1.5 to 2 inches (38 to 51 mm) measured
at the clutch pedal pad. Make checks at 3,000 miles
(5 000 km) and 6,000 miles (10 000 km) and then every
6,000 miles (10 000 km) thereafter.
(11) = Inspect rear axle air shift motor for fluid leaks.
Remove plug to check fluid level. Inspect air lines and
hoses for proper hook
-up, binding, leaks, etc. Inspect at
3,000 miles (5 000 km) and 24,000 miles (40 000 km)
and then every 24,000 miles (40 000 km) thereafter.
(12) = Chassis Lubrication Service: Lubricate all grease
fittings in front suspension, front axle and steering
linkage. DO NOT lubricate kingpin bushings with air
pressure equipment; instead, use a hand grease gun to
ensure complete purge and eliminate sealer cap
distortion. Lubricate transmission and shift linkage,
hood latches and hood hinges, parking brake lever pivot,
clevis pins and linkage, disc brake caliper rails, clutch
linkage and release bearing (if equipped), propeller shaft
slip joint, universal joint, brake camshaft bracket, slack
adjusters, pedal shaft, clutch cross shaft and clutch pedal
springs. Lubricate suspension, axle and steering linkage
more often when operating under dusty or muddy
conditions and in excessive off
-road use.(13) = Check steering system:

Look for damaged, loose or missing parts. Also
look for parts showing signs of wear or lack of
lubrication. Replace parts as needed. Also check
steering gear mounting bolts, pitman arm nut, gear
housing upper cover and side cover attaching bolts,
steering column mounting bolts and cardan
joint clamp bolts; tighten if necessary.
(See service manual.)

Inspect power steering hoses, tubes and fittings for
leaks. Hoses and lines must not be twisted, kinked or
tightly bent. Make sure clips, clamps, supporting
tubes and hoses are in place and properly secured.

Check steering gear for leakage around pitman shaft
and housing. If leakage is evident (lubricant
oozing out, not just oily film), leak should be
corrected immediately.
(14) = Check front and rear suspension. Look for
damaged, loose or missing parts or parts showing signs
of wear or lack of lubrication. Replace parts as needed.
(15) = Adjust tire pressures as indicated on the
Certification/Tire label for optimum tire life. See ªTiresº
in the Index for further details. Check tires for excessive
or abnormal wear or damage. Also check for damaged
wheels. Replace wheels and/or tires as needed.
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7-21
(25) = Check thermostatically controlled air cleaner
installation to make certain that all ducts are connected and
correctly installed. Also, check valve for proper operation.
(26) = Evaporative Control System Service (if equipped):
Check all fuel and vapor lines and hoses for proper
connections and correct routing (or every 24 months,
whichever occurs first). Replace parts as needed.
(27) = Replace air cleaner filter (or every 24 months,
whichever occurs first). Replace filter more often if
driving in dusty conditions. Ask your dealer for the
proper replacement intervals for your driving conditions.
(28) = Replace spark plugs. Inspect wires for damage.
Check the wire boot and boot heat shield fit at spark
plugs and coil. Replace parts as needed.
(30) = Check the fuel tank, fuel cap and fuel lines for
damage which could cause leakage. Inspect fuel cap for
correct sealing ability and any indications of damage.
Check fuel cap gasket for even filler neck imprint.
Replace parts as needed.
(31) = Check EGR system as described in the service
manual. See ªService and Owner Publicationsº in the Index.
(32) = Inspect Electronic Vacuum Regulator Valve
(EVRV) filter for excessive contamination or plugging.
If needed, clean filter with solution of soap and water,
let dry and install.(33) = Check the PCV system for proper operation and
clean PCV valve. Replace hoses as needed.
(34) = Replace PCV valve and blow out the PCV valve
hose with compressed air. Replace hoses as needed.
(35) = Drain, flush and refill cooling system. See
ªRecommended Fluids and Lubricantsº in the Index for
what to use. Inspect hoses. Clean radiator, condenser,
pressure cap and neck. Pressure test cooling system and
pressure cap. For Caterpillar
 diesel engines, always refer
to the Caterpillar Diesel Engine Operation & Maintenance
Manual for coolant recommendations and change intervals.
(37) = Rear axle service: Change the lubricant. See
ªRecommended Fluids and Lubricantsº in the Index.
(38) = Front axle service: Re
-pack upper kingpin
roller bearing.
(39) = Air brake service:

Inspect brake lines and hoses for proper hook
-up,
binding, leaks, cracks, chafing, etc. Inspect drum
brake linings for wear or cracks. Inspect other brake
parts at each wheel, including drums, wheel cylinders
and piston heat shields and boots. Check brake pedal
for excessive free play or travel (or every 6 months,
whichever occurs first) and have serviced if needed.
Check brakes more often if driving habits and
conditions result in frequent braking.
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7-24 At Least Twice a Year
Restraint System Check
Make sure the safety belt reminder light (if equipped)
and all your belts, buckles, latch plates, retractors and
anchorages are working properly. Look for any other
loose or damaged safety belt system parts. If you see
anything that might keep a safety belt system from
doing its job, have it repaired. Have any torn or frayed
safety belts replaced.
Wiper Blade Check
Inspect wiper blades for wear or cracking. Replace blade
inserts that appear worn or damaged or that streak or
miss areas of the windshield. Also see ªWiper Blades,
Cleaningº in the Index.
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,
damp weather more frequent application may be
required. (See ªRecommended Fluids and Lubricantsº
in the Index.)Body Lubrication Service
Lubricate all surfaces such as door checks, door lock
bolts, lock strike plates, door hinge bushings and
dovetail bumper wedges. Where oil holes are provided,
a dripless oil can be used. The seat adjusters, seat track,
door weatherstrips and rubber hood bumpers should also
be lubricated.
Part C tells you what to use. More frequent lubrication may
be required when exposed to a corrosive environment.
Parking Brake Check
Park on a fairly steep hill and hold the vehicle with the
parking brake only. This checks holding ability.
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7-27
Door Latches Check
Check that doors close, latch and lock tightly. Check for
broken, damaged or missing parts that might prevent
tight latching.
Hood Latches Check
Check that the hood closes firmly. Check for broken,
damaged, loose or missing parts that might prevent tight
latching. Make sure the secondary latch (if equipped)
keeps the hood from opening all the way when the
primary latch is released.
Fluid Leaks Check
Check for fuel, coolant, oil or other fluid leaks by
looking at the surface beneath the vehicle after it has
been parked for a while.
Underbody Inspection
Corrosive materials used for ice, snow removal and dust
control can collect on the underbody. If these materials
are not removed, accelerated corrosion (rust) can occur
on underbody parts such as fuel lines, frame, floor pan
and exhaust system. At least every spring, flush these materials from the underbody with plain water. Take
care to clean well any areas where mud and other debris
can collect. Sediment packed in closed areas of the
frame should be loosened before being flushed.
Engine Cover Check
Check that the cab's engine cover and seal (if equipped)
are not torn or damaged. Be sure that the cover is bolted
down firmly to the floor.
At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
specified in Part C.
Underbody Flushing Service
At least every spring, use plain water to flush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
Tractor Protection (Breakaway) Valve Check
On air brake models, remove, disassemble, clean and
inspect the tractor protection (breakaway) valve.
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7-28
Part C: Recommended Fluids
and Lubricants
NOTE: Fluids and lubricants identified below by
name, part number or specification may be obtained
from your dealer.
USAGE
FLUID/LUBRICANT
Engine Oil
(Gasoline
Engine)Engine Oil with the American
Petroleum Institute Certified For
Gasoline Engines ªStarburstº
symbol of the proper viscosity. To
determine the preferred viscosity
for your vehicle's engine, see
ªEngine Oilº in the Index.
Engine Oil
(Caterpillar
Diesel Engine)See the Caterpillar
Operation &
Maintenance Manual for Engine
Oil recommendations.
Engine Coolant
(GM Gasoline
Engine)50/50 mixture of clean, drinkable
water and use only GM
Goodwrench

DEX-COOL
or
Havoline
DEX-COOL

Coolant. See ªEngine Coolantº in
the Index.
USAGEFLUID/LUBRICANT
Engine Coolant
(Caterpillar
Diesel Engine)See the Caterpillar
Operation &
Maintenance Manual for Engine
Coolant recommendations.
Hydraulic Brake
SystemDelco Supreme 11
Brake Fluid
(GM Part No. 12377967 or
equivalent DOT
-3 Brake Fluid).
Windshield
Washer SolventGM Optikleen
Washer Solvent
(GM Part No. 1051515)
or equivalent.
Clutch Bearing
LubricantClutch Bearing Lubricant (GM
Part No. 12345777 or equivalent)
or NLGI #3 consistency.
Exhaust Brake
Ball Joint Cap
LubricantHigh-Temperature Grease (GM
Part No. 1051344 or equivalent) or
NLGI #3 consistency.
Spring Parking
Brake Hydraulic
PumpDEXRON
-III Automatic
Transmission Fluid.
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7-29
USAGEFLUID/LUBRICANT
Brake Caliper
Housing, Caliper
Support Spring
and Caliper
Support KeyAeroshell #5 Grease (GM Part
No. 12377969 or equivalent).
Air Brake
System Alcohol
EvaporatorCommercial grade of Methyl
Alcohol as specified in
GM 6015
-M.
Power Steering
SystemGM Power Steering Fluid
(GM Part No. 1052884
- 1 pint,
1050017
- 1 quart, or equivalent).
Manual
TransmissionSynthetic Manual Transmission
Fluid (GM Part No. 12345724) is
the recommended lubricant to use.
USAGEFLUID/LUBRICANT
Automatic
TransmissionSee the Allison Transmission
Operator's Manual for correct
Transmission Fluid.
Chassis
LubricationChassis Lubricant (GM Part
No. 12377985 or equivalent) or
lubricant meeting requirements
of NLGI # 2, Category LB
or GC
-LB.
Wheel Bearing
GreaseWheel Bearing Lubricant meeting
requirements of NLGI # 2,
Category GC or GC
-LB (GM
Part No. 1051344 or equivalent).
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