1999 GMC C-SERIES inflation pressure

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4-28
If you have a diesel engine, you may have to run it at a
higher speed to get enough heat. Then, shut the engine
off and close the window almost all the way to preserve
the heat. Start the engine again and repeat this only
when you feel really uncomfortable from the cold. But
do it as little as possible. Preserve the fuel as long as you
can. To help keep warm, you can get out of the vehicle
and do some fairly vigorous exercises every half hour or
so until help comes.Loading Your Vehicle
The GVW/Tire Information label is found on the rear
edge of the driver's door. The label shows the size of
your original tires and the inflation pressures needed to
obtain the gross weight capacity of your vehicle.
This is called the Gross Vehicle Weight Rating
(GVWR). The GVWR includes the weight of the
vehicle, all occupants, fuel and cargo.
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5-36
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.
CAUTION:

There are many ways to be hurt badly, or
be killed, while you are trying to change a
truck tire and rim. Follow all of the safety
precautions on the truck jack and
other equipment.
CAUTION: (Continued)
CAUTION: (Continued)

If you try to put air back into a tire that has
run flat, or even a tire that was quite low on
air, without first finding out why it was low
or flat, the tire can have a sudden air
-out.
This could cause you to lose control of the
vehicle and have a serious crash. Don't
refill a flat or very low tire with air without
first having the tire taken off the wheel and
checked for damage.

Use a clip-on chuck and hose extension when you
add air to your tires. You'll need an accurate truck
tire pressure gage. Stand to one side and add the air.
Be sure you don't go over the top inflation pressure
for the tire.
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6-49 Inflation -- Tire Pressure
The Certification/Tire label, which is on the driver's
door, shows the correct inflation pressures for your tires
when they're cold. ªColdº means your vehicle has been
sitting for at least three hours or driven no more than
1 mile (1.6 km).
NOTICE:
Don't let anyone tell you that underinflation or
overinflation is all right. It's not. If your tires
don't have enough air (underinflation), you can
get the following:

Too much flexing

Too much heat

Tire overloading

Bad wear

Bad handling

Bad fuel economy.
NOTICE: (Continued)
NOTICE: (Continued)
If your tires have too much air (overinflation),
you can get the following:

Unusual wear

Bad handling

Rough ride

Needless damage from road hazards.
When to Check
Check your tires once a month or more. Also, check the
tire pressure of the spare tire.
How to Check
Use a good quality pocket
-type gage to check tire
pressure. You can't tell if your tires are properly inflated
simply by looking at them. Radial tires may look
properly inflated even when they're underinflated.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt
and moisture.
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6-50 Rims and Wheels
Rims and wheels are stamped with a maximum load and
cold inflation rating. Be sure you don't exceed these limits.
Dual Tire Operation
When the vehicle is new, or whenever a wheel, wheel
bolt or wheel nut is replaced, check the wheel nut torque
as indicated:
If your vehicle has stud piloted or hub piloted wheels,
tighten the wheel stud nuts to the specified torque values
at 100 miles (160 km), 500 miles (800 km) and
1,000 miles (1 600 km) and then every 1,000 miles
(1 600 km) thereafter.
For proper torque, see ªWheel Nut Torqueº in the Index.
The outer tire on a dual wheel setup generally wears
faster than the inner tire. Your tires will wear more
evenly and last longer if you rotate the tires periodically.
If you're going to be doing a lot of driving on
high
-crown roads, you can reduce tire wear by adding
5 psi (35 kPa) to the tire pressure in the outer tires. Be
sure to return to the recommended pressures when no
longer driving under those conditions. See ªChanging a
Flat Tireº in the Index for more information.
CAUTION:
If you operate your vehicle with a tire that is
badly underinflated, the tire can overheat. An
overheated tire can lose air suddenly or catch
fire. You or others could be injured. Be sure
all tires (including the spare, if any) are
properly inflated.
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6-58
CAUTION:
Without the correct wheel, you may not be able
to stop properly, and you could have other
problems like a tire air
-out. You could have a
collision. If you don't go to your dealer to get a
new wheel, be sure you get the correct one. Each
new wheel should match the original wheel in
load
-carrying capacity, inflation pressure
capacity, diameter, width, offset and mounting
configuration.
Using wheels and tires with higher load-carrying limits
than the original wheels and tires doesn't change the
GAWR or the GVWR of your vehicle.
NOTICE:
The wrong wheel can cause trouble in bearing
life, brake cooling, speedometer/odometer
calibration, headlamp aim, bumper height,
vehicle ground clearance, stopping distance and
tire clearance to the body and chassis. You could
also have other problems like a tire air
-out.
Used Replacement Wheels
CAUTION:
Putting a used wheel on your vehicle is
dangerous. You can't know how it's been used or
how many miles it's been driven. It could fail
suddenly and cause an accident. If you have to
replace a wheel, use a new GM original
equipment wheel.
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7-23
Part B: Owner Checks and Services
Listed in this part are owner checks and services which
should be performed at the intervals specified to help
ensure the safety, dependability and emission control
performance of your vehicle.
For your safety and that of others, any of the
safety
-related components that may have been damaged
in an accident should be checked and any needed repairs
made before operating the vehicle.
At the minimum, these routine checks should be made
every 6 months or 6,000 miles (10 000 km), whichever
occurs first. Whenever repairs are needed, have them
completed before operating the vehicle.
At Each Fuel Fill
It is important for you or a service station attendant to
perform these underhood checks at each fuel fill.Engine Oil Level Check
Check the engine oil level and add the proper oil if
necessary. See ªEngine Oilº in the Index for
further details.
Engine Coolant Level Check
Check the engine coolant level and add DEX
-COOL

coolant mixture if necessary. See ªEngine Coolantº in
the Index for further details.
Windshield Washer Fluid Level Check
Check the windshield washer fluid level in the
windshield washer tank and add the proper fluid if
necessary. See ªWindshield Washer Fluidº in the Index
for further details.
Tire Inflation Check
Check tire inflation cold. Make sure tires are inflated to
the pressures specified on the Certification/Tire label.
See ªTiresº in the Index for further details.
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9-5
Gages
Air Pressure 2-69 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Coolant Temperature 2-61 . . . . . . . . . . . . . . . . . . . .
Engine Oil Pressure 2-65 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filterminder 2-70 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel 2-68 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hourmeter 2-70 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Pressure 2-65 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Speedometer 2-53 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tachometer 2-54 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission Temperature 2-69 . . . . . . . . . . . . . . . . . . . . . .
Voltmeter 2-56 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Guide en Fran†ais ii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hazard Warning Flasher Switch 5-3 . . . . . . . . . . . . . . . . . . .
Hazard Warning Flashers 5-2 . . . . . . . . . . . . . . . . . . . . . . . . . .
Head Restraints 1-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Headlamps 2-43 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High/Low Beam Changer 2-34 . . . . . . . . . . . . . . . . . . . . . .
Wiring 6-68 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heating 3-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Highway Hypnosis 4-21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hill and Mountain Roads 4-22 . . . . . . . . . . . . . . . . . . . . . . . . .
Hood
Access Panels 6
-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking Things Under 6-9 . . . . . . . . . . . . . . . . . . . . . . . . .
Latches Check 7-27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Horn 2-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hourmeter Gage 2
-70 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hydraulic Brake Warning Light 2-58 . . . . . . . . . . . . . . . . . . . .
Hydroplaning 4-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ignition Positions 2-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inflation, Tire 6-49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspections
Engine Cover Check 7
-27 . . . . . . . . . . . . . . . . . . . . . . . . . .
Underbody 7-27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Instrument Panel 2-50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Breaker Block 6-69 . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning 6-61 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cluster 2-52 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Intake Heater Indicator Light 2-63 . . . . . . . . . . . . . . . . . . . . . .
Inter-Axle Differential Lock Control 2-40 . . . . . . . . . . . . . . . .
Jump Starting 5-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Keys 2-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Labels
Certification/Tire 4-28, 6-67 . . . . . . . . . . . . . . . . . . . . . . . .
Service Parts Identification 6-67 . . . . . . . . . . . . . . . . . . . . .
Vehicle Identification Number 6-67 . . . . . . . . . . . . . . . . . . .
Lamp and Bulb Data 6-74 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lamp Check 7-26 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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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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