automatic transmission GMC C-SERIES 1999 Owner's Manual

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6-18
CAUTION:
Gasoline Engines Only: Operating the engine
with the air cleaner/filter off can cause you or
others to be burned. The air cleaner not only
cleans the air, it stops flame if the engine
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/filter off.
NOTICE:
Gasoline Engines Only: If the air cleaner/filter 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/filter
in place when you're driving.
Your vehicle may also be equipped with an optional
Filterminder gage. See ªWarning Lights, Gages and
Indicatorsº in the Index.
Automatic Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
checked. See your Allison Automatic Transmission
Operator's Manual to find out when to change your
transmission fluid and filters.
How to Check and What to Use
The Allison Automatic Transmission Operator's Manual
that came with the vehicle shows how to check the
automatic transmission fluid and what fluid to use.
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.
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6-19 Automatic Transmission External Filter
Your automatic transmission spin-on type filter requires
periodic replacement. It is mounted just behind the
radiator on the outside of the passenger's side frame rail.
Consult the Allison Automatic Transmission Operator's
Manual that came with the vehicle for proper
change intervals.
Automatic Transmission External Filter
With Service Trans Filter Indicator Light
(Option)
This automatic transmission spin-on type filter is
mounted to the left of the transmission. It requires
replacement when the SERVICE TRANS FILTER
indicator light on the instrument panel comes on or
every three years, whichever occurs first.
Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
checked. See your Maintenance Schedule to find out
when to change your transmission fluid and filters.
How to Check and What to Use
The Eaton Fuller Transmission Operator's Manual that
came with the vehicle shows how to check the manual
tranmsmission fluid and what fluid to use.
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.
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6-36
Electric/Hydraulic Parking
Brake Fluid
If you have an electric/hydraulic parking brake, a good
time to check the fluid level is when you check the fluid
levels under the hood.
If you need to add fluid, use Dexron III automatic
transmission fluid (GM Part Number 12345881).
How to Check and Add Fluid
First, apply the parking brake. To check the fluid level,
look at the MAX and MIN lines on the side of the
reservoir. If the level is below the MAX line, add fluid.
To add fluid, clean away any dirt around the reservoir
cap. Remove the reservoir cap and add enough fluid to
bring it up to the MAX level.
NOTICE:
Always use proper fluid (automatic transmission
fluid), not brake fluid. Failure to use the proper
fluid can cause leaks and damage hoses and seals.
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6-74
Replacement Bulbs
It is recommended that you use an AC
type bulb
whenever you need to replace one.
Before you replace any bulbs, be sure that all lamps are
off and the engine isn't running.
Capacities and Specifications
Replacement part numbers listed in this section are
based on the latest information available at the time of
printing. They are subject to later change. If a part listed
here isn't the same as the part in your vehicle when it
was built, or if you have any questions, please contact
your GM Truck dealer.
Engine Identification and Data
Engine RPO LG5 LP4/L21
Engine Type 7.2L L6 7.4L V8
Fuel System HEUI SPFI
Firing Order
1
-5-3-6-2-41-8-4-3-6-5-7-2
Wheel Nut Torque
Refer to ªTightening the Wheel Nutsº in this section for
wheel nut torque information.
Cooling System Capacity
Model Quarts (Liters)
7.2L 32.0 (30.0). . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
with automatic transmission 30.0 (28.4). . . . . . . . . .
7.4L 25.0 (23.7). . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
with automatic transmission 23.0 (22.7). . . . . . . . . .
Above capacities (volumes) are approximate.
Crankcase Capacity
Capacities (volumes) shown are for normal refill. Add
oil as indicated when the oil filter element is changed.
Capacities given are approximate
-- keep level within
the operating range. Do not operate with fluid level
below the ADD line.
Engine
Capacity
-- Quarts (Liters)
7.2L 21 (19.0)*
7.4L 8 (7.5)
*Additional oil is required with auxiliary oil filter
systems. Make sure to add enough extra oil to fill the
auxiliary oil filter system. For vehicles equipped with
the LUBERFINER 750
-C, add 14 quarts (13.25 L).
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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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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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7-25
Starter Switch Check
CAUTION:
When you are doing this check, the vehicle could
move suddenly. If it does, you or others could be
injured. Follow the steps below.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake (see ªParking
Brakeº in the Index if necessary) and the
regular brakes.
NOTE: Do not use the accelerator pedal, and be
ready to turn off the engine immediately if it starts.
3. On automatic transmission vehicles, try to start the
engine in each gear. The starter should work only in
PARK (P), if equipped, or NEUTRAL (N). If the
starter works in any other position, your vehicle
needs service.Automatic Transmission Shift Indicator Check
Check that the indicator points to the gear chosen.
Steering Check
Be alert for any changes in steering action, abnormal
front tire wear or steering wheel position. An inspection
or service is needed when the steering wheel is harder to
turn or has too much free play, or if there are strange
sounds when turning or parking.
Brake System Check
Be alert to illumination of the low air warning lamp or
for the tone alarm, or changes in braking action, such as
repeated pulling to one side, unusual sounds when
braking or increased brake pedal travel. Make sure air
brake system reservoirs are drained daily with full
system air pressure, and check system for leaks. Any of
these conditions could indicate the need for brake
system inspection and/or service.
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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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9-1
Section 9 Index
A
ir
Brake System Warning Light 2-59 . . . . . . . . . . . . . . . . . . . .
Cleaner 6-17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaner Filter 6-77 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compressor Filter 6-77 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conditioning 3-5, 6-77 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conditioning Refrigerants 6-77 . . . . . . . . . . . . . . . . . . . . . .
Dryer 6-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filter Restriction Indicator 6-17 . . . . . . . . . . . . . . . . . . . . . .
Suspension 2-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air Brake Systems 6-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air Dryer 6-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Alcohol Injector 6-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Moisture Ejector 6-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Alcohol Injector 6-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Alignment and Balance, Tire 6-51 . . . . . . . . . . . . . . . . . . . . . .
AM-FM Stereo 3-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AM-FM Stereo with Remote Cassette Tape Player 3-10 . . . . .
Antenna 3-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Antifreeze 6-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Anti-Lock
Brakes 4-7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake System Warning Light 2-61, 4-7 . . . . . . . . . . . . . . . .
Appearance Care 6-59 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appearance Care Materials 6-66 . . . . . . . . . . . . . . . . . . . . . . . Apply Park Brake Warning Light 2
-60 . . . . . . . . . . . . . . . . . .
Ashtray 2-47 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Audio Systems 3-7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic Transmission Fluid 6-18 . . . . . . . . . . . . . . . . . . . . .
Automatic Transmission Shift Indicator Check 7-25 . . . . . . . .
Auxiliary Power Jacks 2-48 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Axle, Rear 6-20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Airshift Control 2-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Differential Lock Control 2-41 . . . . . . . . . . . . . . . . . . . . . . .
Fluid Capacity 6-76 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shift Motor 6-20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tw o-Speed Electric Shift Control 2-17 . . . . . . . . . . . . . . . .
Towing 5-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery 6-42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery, Jump Starting 5-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake
Adjustment 6
-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air Brake Systems 6-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air Parking Brake 2-26 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electric/Hydraulic Parking Brake 2-25 . . . . . . . . . . . . . . . .
Electric/Hydraulic Parking Brake Fluid 6-36 . . . . . . . . . . . .
Exhaust 2-16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid 6-30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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