maintenance CHEVROLET C/K 2003 Owner's Manual

6-34
Rear Axle
When to Check and Change Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant and when to change it. See
ªScheduled Maintenance Servicesº in the Index.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.If the level is below the bottom of the filler plug hole,
you'll need to add some lubricant. Add enough lubricant
to raise the level to the bottom of the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Index.
Rear Axle Shift Motor (Option)
When to Check and Change Fluid
If you have an optional air-shift two-speed, controlled
traction, or locking differential type rear axle, a good
time to check the fluid level in the axle shift motor is
when the rear axle lubricant is checked. Use refrigerant
oil (shift motor only).
How to Check Fluid
Remove the plug on the front plate of the axle shift
motor, add enough fluid to raise the level to the bottom
of the filler plug hole, then replace the plug.
What to Use
Refer to your Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Index.

6-35
Engine Coolant
If your vehicle has a Caterpillar diesel engine, the
Caterpillar Operation & Maintenance Manual provided
with your vehicle has information regarding the proper
coolant to use.
The cooling system in your vehicle is filled with
DEX
-COOL engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX
-COOL extended life coolant.
The following explains your cooling system and how
to add coolant when it is low. If you have a problem
with engine overheating, see ªEngine Overheatingº in
the Index.A 50/50 mixture of clean, drinkable water and
DEX
-COOL coolant will:

Give freezing protection down to
-34F (-37C).

Give boiling protection up to 252F (122C).

Protect against rust and corrosion.

Help keep the proper engine temperature.

Let the warning lights and gages work as
they should.
NOTICE:
When adding coolant, it is important that you use
only DEX
-COOL (silicate-free) coolant.
If coolant other than DEX-COOL is added to the
system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the use
of coolant other than DEX
-COOL is not
covered by your new vehicle warranty.

6-38
Adding Coolant
If you need more coolant, add the proper DEX
-COOL

coolant mixture at the surge tank, but only when the
engine is cool.
CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Don't spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand
-tight.
Engine Coolant (Caterpillar

Diesel Engine)
If your vehicle has a Caterpillar diesel engine, see the
Caterpillar
Diesel Engine Operation & Maintenance
Manual provided with your vehicle to find out what to
add, also when and how to service your cooling system.
Surge Tank Pressure Cap
The surge tank pressure cap
is located in the engine
compartment, on the
driver's side of the vehicle.
The surge tank pressure cap must be tightly installed.
NOTICE:
Your surge tank pressure cap is a 15 psi (103kPa)
pressure
-type cap for use with medium duty
cooling systems only. It must be tightly installed
to prevent coolant loss and possible engine
damage from overheating.

6-39
Power Steering Fluid
See your Maintenance Schedule for when to check your
power steering fluid.
How To Check Power Steering Fluid
Check your power steering fluid only when the engine is
warm. If the engine isn't warm, you probably won't get
an accurate reading.
If the fluid level is
between the MIN and
MAX marks, you have
enough. If you need
fluid, add only enough
of the proper fluid to
bring it into view in
the sight glass.If your power steering fluid level is low, this can cause
the BRAKE or service brake soon warning lights to
come on. If either light remains on after you have added
power steering fluid to the proper level, then shut off the
engine for 10 seconds. This should reset the brake
warning lights. If one or both lights stay on though, see
ªHydraulic Brake Warning Lightsº in the Index.
What to Use
To determine what kind of fluid to use, see
ªRecommended Fluids and Lubricantsº in the Index.
NOTICE:
When adding power steering fluid or making a
complete fluid change, always use the proper
fluid. Failure to use the proper fluid can cause
leaks and damage hoses and seals.

6-41
NOTICE:

When using concentrated washer fluid,
follow the manufacturer's instructions for
adding water.

Don't mix water with ready
-to-use washer
fluid. Water can cause the solution to freeze
and damage your washer fluid tank and
other parts of the washer system. Also,
water doesn't clean as well as washer fluid.

Fill your washer fluid tank only
three
-quarters full when it's very cold.
This allows for expansion if freezing occurs,
which could damage the tank if it is
completely full.

Don't use engine coolant (antifreeze) in
your windshield washer. It can damage
your washer system and paint.
Brakes
Brake Fluid
If your vehicle has hydraulic brakes, there's a brake
master cylinder. Refer to the Maintenance Schedule to
determine when to check your brake fluid.
CAUTION:
Don't add brake fluid before you check the level.
If you do, you could get too much brake fluid.
Brake fluid could spill on the hot engine and it
can catch fire. You could be burned and your
vehicle could be damaged. See ªChecking Brake
Fluidº in this section.

6-43
What to Add
Use the proper fluid listed in your Maintenance
Schedule. Use new brake fluid from a sealed
container only.
Always clean the brake fluid reservoir cap/cover and the
area around the cap/cover before removing it. This will
help keep dirt from entering the reservoir.
CAUTION:
With the wrong kind of fluid in your brake
system, your brakes may not work well, or they
may not even work at all. This could cause a
crash. Always use the proper brake fluid.
NOTICE:

Using the wrong fluid can badly damage
brake system parts. For example, just a few
drops of mineral
-based oil, such as engine
oil, in your brake system can damage brake
system parts so badly that they'll have to be
replaced. Don't let someone put in the
wrong kind of fluid, and don't use DOT
-5
silicone brake fluid.

If you spill brake fluid on your vehicle's
painted surfaces, the paint finish can be
damaged. Be careful not to spill brake fluid
on your vehicle. If you do, wash it off
immediately. See ªAppearance Careº in
the Index.

6-46 Air Brake Systems (If Equipped)
If you have air brakes, it is important to get rid of
moisture in the system. Moisture will damage your
system if it isn't removed daily.
There are two ways to do this. One is automatic if your
air
-brake vehicle has the optional moisture ejector.
If your vehicle doesn't have that option, however, you
must drain the air reservoirs occasionally to be sure the
air dryer is working properly.
Drain the air brakes at full system pressure. To be sure
you're at full pressure, check your air pressure gage.
It should read at least 100 psi (692 kPa).
Moisture Ejector (Option)
If you have air brakes with a moisture ejector, the valve
automatically ejects moisture from the reserve tank
when the air compressor cycles.
Air Dryer
If your vehicle has air brakes, you have an air dryer.
This collects and removes dirt, moisture or other foreign
matter from the air prior to entering the brake system.
It is mounted on the passenger's side frame rail.
If your dryer is a Bendix
-Westinghouse, it has a
filter that you need to change at intervals. See your
Maintenance Schedule for more about servicing
this filter.

6-47 Electric Air Compressor (If Equipped)
Your vehicle may be equipped with an electric air
compressor. This compressor is used to run options that
require pressurized air, such as an air horn, air seat,
exhaust restrictor or an exhaust brake.
This air compressor is used when vehicles are not
equipped with an air brake system.
The air supply for this
system must be maintained
by releasing the drain
valve to eject any moisture
that may have built up in
the system.
It is recommended that this system be drained on a
weekly basis.
Clutch Pedal Free Travel
If you have a manual transmission, your clutch will need
adjustment when pedal free travel gets down to about
1/4 inch (32 mm), as measured at the clutch pedal pad.
You should have 1 1/2 to 2 inches (38 to 51 mm) of
clutch pedal free travel. See ªMaintenance Scheduleº in
the Index for more information.
If your clutch ever needs service, be sure to use only
genuine GM clutch replacement parts.
Chassis Lubrication
Your Maintenance Schedule provides all of the required
chassis lubrication intervals and identifies proper
lubricants to use. Be sure to see your Maintenance
Schedule before performing any chassis lubrication
service. To determine location of chassis lubrication
items, use the following charts.

6-52
Battery
Your new vehicle comes with one or more maintenance
free ACDelco
batteries. When it's time for a new
battery, be sure it has the replacement number shown
on the original battery's label. We recommend an
ACDelco battery.
WARNING: Battery posts, terminals and related
accessories contain lead and lead compounds, chemicals
known to the State of California to cause cancer and
reproductive harm. Wash hands after handling.
Vehicle Storage
If you're not going to drive your vehicle for 25 days or
more, remove the black, negative (
-) cable from the
battery. This will help keep your battery from running
down. (If your vehicle has more than one battery, be
sure to remove the negative (
-) battery cable from
each battery.)
CAUTION:
Batteries have acid that can burn you and gas
that can explode. You can be badly hurt if you
aren't careful. See ªJump Startingº in the Index
for tips on working around a battery without
getting hurt.
When you are ready to use the vehicle again, refer to the
engine starting procedure in the Index.
Contact your dealer to learn how to prepare your vehicle
for longer storage periods.

6-54
Other Service Items
Fuel Filter (Gasoline Engines)
The steel fuel filter is located near the engine
compartment on the driver's side of the vehicle.
See your Maintenance Schedule for recommended
service intervals.If your vehicle is equipped with the optional Davco
spin
-on type filter, it is located on the driver's side
frame rail.
Fuel Filter (Diesel Engines)
If you have a diesel engine, your fuel filter is located in
the engine compartment on the driver's side of the
vehicle, or along the driver's side frame rail. See ªFuel
Filter Replacementº earlier in this section for further
information.
Also see your Maintenance Schedule for recommended
service intervals.