2002 CHEVROLET C3500 HD fuel

6-11
Engine Oil (Gasoline Engine)
If your vehicle has a diesel engine, see ªEngine Oil
(Diesel Engine)º in the Diesel Engine Supplement.
Checking Engine Oil
It's a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil must
be warm and the vehicle must be on level ground.
The engine oil dipstick
has a yellow ring handle
and is located in the
engine compartment on
the passenger's side of
the vehicle. See ªEngine
Compartment Overviewº
in the Index for more
information on location.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don't, the oil dipstick
might not show the actual level.Pull out the dipstick and clean it with a paper towel or
cloth, then push it back in all the way. Remove it again,
keeping the tip down, and check the level.
When to Add Engine Oil
If the oil is at or below the ADD mark, then you'll need
to add at least one quart of oil. But you must use the
right kind. This part explains what kind of oil to use.
For engine oil crankcase capacity, see ªCapacities and
Specificationsº in the Index.

6-41 Inflation -- Tire Pressure
The Certification/Tire label, which is on the rear edge of
the driver's door, or on the incomplete vehicle document
in the cab, 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
(if equipped).
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.

6-57
Underbody Maintenance
Chemicals used for ice and snow removal and dust
control can collect on the underbody. If these are
not removed, accelerated corrosion (rust) can occur
on the underbody parts such as fuel lines, frame,
floor pan and exhaust system even though they have
corrosion protection.
At least every spring, flush these materials from the
underbody with plain water. Clean any areas where mud
and other debris can collect. Dirt packed in closed areas
of the frame should be loosened before being flushed.
Your dealer or an underbody car washing system can
do this for you.
Chemical Paint Spotting
Some weather and atmospheric conditions can create
a chemical fallout. Airborne pollutants can fall upon
and attack painted surfaces on your vehicle. This
damage can take two forms: blotchy, ringlet
-shaped
discolorations, and small irregular dark spots etched into
the paint surface.
Although no defect in the paint job causes this, GM
will repair, at no charge to the owner, the surfaces of
new vehicles damaged by this fallout condition within
12 months or 12,000 miles (20 000 km) of purchase,
whichever occurs first.

6-64
Underhood Fuse Block
The underhood fuse block is located in the rear of the
engine compartment near the brake fluid reservoir.
See ªEngine Compartment Overviewº in the Index
for more information on location. Move the retainer
clips for the cover to access the fuse block.
You can remove fuses with a fuse extractor which is
mounted to the interior fuse block. To remove fuses
if you don't have a fuse extractor, hold the end of the
fuse between your thumb and index finger and pull
straight out.
Name Usage
Starter Relay Starter
A/C Relay Air Conditioning
Fuel Pump Relay Fuel Pump
Brake Lamp
RelayBrake Lamp
Blank Not Used

6-65
Name Usage
Horn Relay Horn
ECM
-B Fuel Pump, PCM/VCM
RR DEFOG Not Used
IGN
-E A/C Compressor Relay,
Dual Tanks
Blank Not Used
Blank Not Used
Blank Not Used
HORN Horn, Underhood Lamps
AUX FAN Not Used
ECM
-1 Injectors, PCM/VCM, Fuel
Solenoid (Diesel Engine) Fuel
Control Module (Diesel Engine)
HTD ST
-FR Not Used
Blank Not Used
Blank Not Used
A/C Air Conditioning
PTO PTO RelayName Usage
ENG
-1 Ignition Switch, Exhaust Gas
Recirculation, Canister Purge,
EVRV Idle Coast Solenoid, MAF,
Heated O
2, Fuel Heater (Diesel
Engine), Water Sensor (Diesel
Engine), Boost Solenoid (Diesel
Engine), EPR (Diesel Engine)
HTD ST
-RR Not Used
Blank Not Used
Diode Not Used
LIGHTING Headlamp and Panel Dimmer
Switch, Fog and Courtesy Fuses
BATT Battery, Fuse Block Busbar
IGN A Ignition Switch
IGN B Ignition Switch
ABS Anti
-Lock Brake Module
BLOWER High Blower Relay
STOP/HAZ Stoplamps
HEATED
SEATSNot Used

6-67 Capacities
After refill, the level must be rechecked. See ªCooling
Systemº in the Index.
Engine VIN Quantity
ªVORTECº 8100 G 28.5 quarts (27.0 L)
Engine Oil with Filter
After refill, the level must be rechecked. Add enough
engine oil so that the fluid is within the proper operating
range. See ªEngine Oilº in the Index.
Engine VIN Quantity
ªVORTECº 8100 G 6.6 quarts (6.3 L)
Fuel Tank Capacity
Type Quantity
Front Tank 22.0 U.S. gallons (79 L)
Rear Tank 18.0 U.S. gallons (68 L)
Air Conditioning
Refrigerant Capacity
If you do your own service work, you'll need the proper
service manual. See ªDoing Your Own Service Workº in
the Index for additional information. It is recommended
that service work on your air conditioning system be
performed by a qualified technician.
Air Conditioning
Refrigerant R
-134a 2.0 lbs (0.91kg). . . . . . . . . . . . .
Use Refrigerant Oil, R134a Systems

6-68
Normal Maintenance
Replacement Parts
Replacement part numbers listed in this section are
based on the latest information available at the time of
printing, and are subject to change. If a part listed in
this manual is not the same as the part used in your
vehicle when it was built, or if you have any questions,
please contact your GM truck dealer.
These specifications are for information only. If you
have any questions, see the service manual for the
chassis or refer to the body manufacturer's publications.VIN Code G. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Filter* PF454. . . . . . . . . . . . . . . . . . . . . . . .
Engine Air Cleaner Filter* A1300C . . . . . . . .
Spark Plugs*** TJ14R-P15 . . . . . . . . . . . . . . .
Fuel Filter* GF626. . . . . . . . . . . . . . . . . . . . . . .
Wiper Blades** 22154886. . . . . . . . . . . . . . . . .
Wiper Blade Type Trico. . . . . . . . . . . . . . . . . .
Wiper Blade Length 18 inches (45.0 cm). . . . . .
*ACDelco

part number
**GM part number
***Denso part number
A1301C high
-capacity air cleaner filter.

7-4
Part A: Scheduled Maintenance
Services
Using Your Maintenance Schedule
We at General Motors want to help you keep your
vehicle in good working condition. But we don't know
exactly how you'll drive it. You may drive very short
distances only a few times a week. Or you may drive
long distances all the time in very hot, dusty weather.
You may use your vehicle in making deliveries.
Or you may drive it to work, to do errands or in
many other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You may need more
frequent checks and replacements. So please read the
following and note how you drive. If you have any
questions on how to keep your vehicle in good
condition, see your dealer.
This part tells you the maintenance services you should
have done and when you should schedule them. If you
go to your dealer for your service needs, you'll know
that GM
-trained and supported service people will
perform the work using genuine GM parts.The proper fluids and lubricants to use are listed in
Part D. Make sure whoever services your vehicle
uses these. All parts should be replaced and all
necessary repairs done before you or anyone else
drives the vehicle.
These schedules are for vehicles that:

carry passengers and cargo within recommended
limits. You will find these limits on your vehicle's
Certification/Tire label. See ªLoading Your Vehicleº
in the Index.

are driven on reasonable road surfaces within legal
driving limits.

use the recommended fuel. See ªFuelº in the Index.
Selecting the Right Schedule
First you'll need to decide which of the two schedules is
right for your vehicle. Here's how to decide which
schedule to follow: