1999 GMC C-SERIES steering

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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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7-25
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.
ProCarManuals.com

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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).
ProCarManuals.com

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8-8
CURRENT PUBLICATIONS FOR 1999 GMC
SERVICE MANUALS
Service Manuals have the diagnosis and repair information
on engines, transmission, axle, suspension, brakes,
electrical, steering, body, etc.
RETAIL SELL PRICE: $90.00
TRANSMISSION, TRANSAXLE, TRANSFER CASE
UNIT REPAIR MANUAL
This manual provides information on unit repair service
procedures, adjustments and specifications for the
1999 GM transmissions, transaxles and transfer cases.
RETAIL SELL PRICE: $50.00
SERVICE BULLETINS
Service Bulletins give technical service information needed
to knowledgeably service General Motors cars and trucks.
Each bulletin contains instructions to assist in the
diagnosis and service of your vehicle.OWNER'S INFORMATION
Owner publications are written directly for Owners and
intended to provide basic operational information about the
vehicle. The owner's manual will include the Maintenance
Schedule for all models.
In-Portfolio: Includes a Portfolio, Owner's Manual and
Warranty Booklet.
RETAIL SELL PRICE: $15.00
Without Portfolio: Owner's Manual only.
RETAIL SELL PRICE: $10.00
CURRENT & PAST MODEL ORDER FORMS
Service Publications are available for current and past
model GM vehicles. To request an order form, please
specify year and model name of the vehicle.
PLEASE COMPLETE THE ORDER FORM SHOWN ON
THE FOLLOWING PAGE AND MAIL TO:
Helm, Incorporated
P.O. Box 07130
Detroit, MI 48207OR ORDER TOLL FREE: 1-800-551-4123
Monday-Friday 8:00 AM ± 6:00 PM Eastern Time
For Credit Card Orders Only (VISA±MasterCard±Discover)
1999 GMC SERVICE PUBLICATIONS ORDERING INFORMATION
The following publications covering the operation and servicing of your vehicle can be purchased by filling out
the Service Publication Order Form in this book and mailing it in with your check, money order,
or credit card information to Helm, Incorporated (address below.)
ProCarManuals.com

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9-7
New Vehicle ªBreak-Inº 2-5 . . . . . . . . . . . . . . . . . . . . . . . . .
Night Vision 4-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Noise Control System 6-11 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Odometer 2-53 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Off-Road Recovery 4-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil, Engine 6-13, 6-17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Owner Checks and Services 7-23 . . . . . . . . . . . . . . . . . . . . . . .
Owner Publications Order Form 8-9 . . . . . . . . . . . . . . . . . . . .
Owner Publications, Ordering 8-8 . . . . . . . . . . . . . . . . . . . . . .
Paint Spotting, Chemical 6-65 . . . . . . . . . . . . . . . . . . . . . . . .
Parking
Brake 2
-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake Check 7-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake Indicator Light 2-60 . . . . . . . . . . . . . . . . . . . . . . . . . .
Over Things That Burn 2-29 . . . . . . . . . . . . . . . . . . . . . . . .
Passing 4-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power
Door Locks 2
-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Option Fuses 6-69 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering 4-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering Fluid 6-28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Windows 2-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Take-Off (PTO) 4-31 . . . . . . . . . . . . . . . . . . . . . . . . . .
Pregnancy, Use of Safety Belts 1-21 . . . . . . . . . . . . . . . . . . . .
Pressure Caps 6-77 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Problems on the Road 5-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Publications, Service and Owner 8-8 . . . . . . . . . . . . . . . . . . . .
Radiator 5-25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Radiator Pressure Cap 6-21 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Radiator Shutters 2-13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Radio Reception 3-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Axle 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recovery Tank, Coolant 5-22 . . . . . . . . . . . . . . . . . . . . . . . . . .
Refrigerants, Air Conditioning 6-77 . . . . . . . . . . . . . . . . . . . .
Releasing Air Operated Parking Brake 5-15 . . . . . . . . . . . . . .
Remote Cassette Tape Player 3-10 . . . . . . . . . . . . . . . . . . . . . .
Replacement Wheels 6-57 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing Safety Belts 1-36 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reporting Safety Defects 8-6, 8-7 . . . . . . . . . . . . . . . . . . . . . .
Restraints
Checking 1
-36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Child 1-26 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Head 1-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing Parts After a Crash 1-36 . . . . . . . . . . . . . . . . . . .
System Check 7-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Right Passenger Position 1-21 . . . . . . . . . . . . . . . . . . . . . . . . .
Roadside Assistance 8-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rocking Your Vehicle 5-38 . . . . . . . . . . . . . . . . . . . . . . . . . . .
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9-8
Safety Belts 1-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adults 1-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Care 6-61 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Center Passenger Position 1-22 . . . . . . . . . . . . . . . . . . . . . .
Children 1-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driver Position 1-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Extender 1-36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to Wear Properly 1-11 . . . . . . . . . . . . . . . . . . . . . . . . .
Lap Belt 1-22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lap-Shoulder Belt 1-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Larger Children 1-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Questions and Answers 1-10 . . . . . . . . . . . . . . . . . . . . . . . .
Reminder Light 1-7, 2-55 . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing After a Crash 1-36 . . . . . . . . . . . . . . . . . . . . . . . .
Right Passenger Position 1-21 . . . . . . . . . . . . . . . . . . . . . . .
Smaller Children and Babies 1-23 . . . . . . . . . . . . . . . . . . . .
Use During Pregnancy 1-21 . . . . . . . . . . . . . . . . . . . . . . . . .
Why They Work 1-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety Defects, Reporting 8-6, 8-7 . . . . . . . . . . . . . . . . . . . . .
Safety Warnings and Symbols iii. . . . . . . . . . . . . . . . . . . . . . .
Scheduled Maintenance 7
-5 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scheduled Maintenance Services 7-4 . . . . . . . . . . . . . . . . . . . .
Seat Adjuster Check 7-26 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Seatback Latches 1-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Seats
Bucket and Bench 1
-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chugger-Snubber Lock-Out 1-6 . . . . . . . . . . . . . . . . . . . . .
Controls 1-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cushion Adjustment 1-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fore-and-Aft Adjustment 1-5 . . . . . . . . . . . . . . . . . . . . . . . Height Adjustment 1
-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lumbar Adjustments 1-5 . . . . . . . . . . . . . . . . . . . . . . . . . . .
National 1-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Securing a Child Restraint 1-31 . . . . . . . . . . . . . . . . . . . . . . . .
Service 6-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bulletins, Ordering 8-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manuals, Ordering 8-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Park Brake Warning Light 2-60 . . . . . . . . . . . . . . . . . . . . . .
Parts Identification Label 6-67 . . . . . . . . . . . . . . . . . . . . . . .
Publications, Ordering 8-8 . . . . . . . . . . . . . . . . . . . . . . . . . .
Trans Filter Indicator Light 2-64 . . . . . . . . . . . . . . . . . . . . .
Work, Doing Your Own 6-3 . . . . . . . . . . . . . . . . . . . . . . . . .
Service and Appearance Care 6-1 . . . . . . . . . . . . . . . . . . . . . .
Service and Owner Publications 8-8 . . . . . . . . . . . . . . . . . . . .
Sheet Metal Damage 6-64 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signal-Stat Turn Signal 2-33, 5-4 . . . . . . . . . . . . . . . . . . . . . .
Skidding 4-14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications, Engine 6-74 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Speedometer 2-53 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starter Switch Check 7-25 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting Your Diesel Engine 2-10 . . . . . . . . . . . . . . . . . . . . . . .
Starting Your Gasoline Engine 2-7 . . . . . . . . . . . . . . . . . . . . . .
Steam 5-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering 4-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Check 7-25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
In Emergencies 4-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power 4-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tips 4-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wheel, Tilt 2-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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9-9
Storage, Vehicle 6-42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stuck: In Sand, Mud, Ice or Snow 5-37 . . . . . . . . . . . . . . . . . .
Sun Visors 2-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Surge Tank, Coolant 5-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Surge Tank Pressure Cap 6-22 . . . . . . . . . . . . . . . . . . . . . . . . .
Symbols, Vehicle v. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tape Player Care 3-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Theft 2-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermostat 6-22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tilt Steering Wheel 2-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tire Loading 6-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tires 6-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing a Flat 5-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning 6-64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dual Tire Operation 6-50 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inflation 6-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inflation Check 7-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loading 6-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure 6-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rims and Wheels 6-50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wheel Replacement 6-57 . . . . . . . . . . . . . . . . . . . . . . . . . . .
When It's Time for New 6-51 . . . . . . . . . . . . . . . . . . . . . . .
Top Strap 1-30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque, Wheel Nut 6-52 , 6-74 . . . . . . . . . . . . . . . . . . . . . . . .
Towing Your Vehicle 5-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Trailer Brake Hand Control Valve 2
-39 . . . . . . . . . . . . . . . . . .
Trailer Connections 2-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission
Automatic 2
-20, 6-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic Transmission External Filter 6-19 . . . . . . . . . . .
Double-Clutching 2-22 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filters 6-77 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid, Automatic 6-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Capacity 6-75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual 2-22, 6-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual, Fluid 6-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Third Gear Hold 2-21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using the Clutch 2-22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic 6-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual 6-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TTY Users 8-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turn and Lane Change Indicator 2-33 . . . . . . . . . . . . . . . . . . .
Underbody Maintenance 6-65 . . . . . . . . . . . . . . . . . . . . . . . .
Vehicle
Control 4-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Damage Warnings iv. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Identification Number 6
-67 . . . . . . . . . . . . . . . . . . . . . . . . .
Loading 4-28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage 6-42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ventilation System 3-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Visors, Sun 2-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltmeter 2-56 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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