engine oil CHEVROLET C/K 2003 Owner's Guide

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.

6-36 What to Use
Use a mixture of one-half clean, drinkable water and
one
-half DEX-COOL
coolant which won't damage
aluminum parts. If you use this coolant mixture, you
don't need to add anything else.
CAUTION:
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the proper
coolant mixture will. Your vehicle's coolant
warning system is set for the proper coolant
mixture. With plain water or the wrong mixture,
your engine could get too hot but you wouldn't
get the overheat warning. Your engine could
catch fire and you or others could be burned.
Use a 50/50 mixture of clean, drinkable water
and DEX
-COOL
coolant.
NOTICE:
If you use an improper coolant mixture, your
engine could overheat and be badly damaged.
The repair cost wouldn't be covered by your
warranty. Too much water in the mixture can
freeze and crack the engine, radiator, heater core
and other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
NOTICE:
If you use the proper coolant, you don't have to
add extra inhibitors or additives which claim to
improve the system. These can be harmful.

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.

6-49
ITEM NO. ITEM REMARKS
1
Brake Camshaft
One fitting each (apply sparingly).
2 Steering Column Slip Joint* One fitting.
3 Steering Drag Link Ends One fitting at each end.
4 Pivot Points and Hinges Apply chassis lubricant
5 Pivot Points and Hinges Apply chassis lubricant.
6
Slack Adjuster
One fitting.
7 Brake Cam Roller Pins at
interface of pin and shoe
Apply engine oil.
8 Front Steering Knuckles
One fitting each side, lower bushing (hand
-operated
grease gun only). Hand
-pack upper bearing.
9 Front Wheel Bearings
Hand
-pack or lubricate.
10 Steering Tie Rod Ends One fitting each end.
11 Spring Slip Pads*
(Multi
-Leaf Only)Apply chassis lubricant.

6-51
Tandem Axle Models
ITEM
NO. ITEM REMARKS
1 Brake Camshafts One fitting each.
2
Propshaft U
-JointOne fitting each joint.
Lubricate with
GM Part No. 1051344,
Wheel Bearing Lubricant.
4 Brake Shoe
Roller PinsApply engine oil at pin
to shoe joint only.
5 Rear Spring Pin One fitting each side.
6 Rear Axles Fill to level of filler plug.

6-55 Primary Fuel Filter and Water Separator
(If Equipped)
If you have a diesel engine,
you may have this spin
-on
filter. It is located on the
driver's side frame rail.
It has a clear plastic drain bowl at the bottom. Check the
drain bowl occasionally for any water or particles.
To drain the bowl, do the following:
1. Shut off the engine.
2. Partially open the drain valve at the bottom of
the filter.
See ªEngine Oilº in the Index for proper disposal
procedures.
Secondary Fuel Filter and Water
Separator/Heater (If Equipped)
If you have a Caterpillar

diesel engine, you may also
have this spin
-on filter and
fuel separator/heater. It will
be mounted in the engine
compartment on the driver's
side of the vehicle.
It has a metal drain bowl at the bottom. Occasionally,
check the bowl for any water or particles.
To check or drain the bowl, do the following:

Shut off the engine.

Push up on the spring loaded drain valve until clear
fuel is flowing from the valve.
The particles or water will drain out first. See ªEngine
Oilº in the Index for proper disposal procedures.

6-56 Automatic Ether Injection System
(If Equipped)
If you have a Caterpillar
diesel engine, you may have
this feature. The ether
cylinder is located in the
engine compartment on the
driver's side of the vehicle.To change an empty ether cylinder, follow these steps.
1. Loosen the screw head on the cylinder
-to-bracket
clamp.
2. Spread the clamp apart.
3. Clean any dirt from the neck of the cylinder and the
top of the valve before you take out the cylinder.
4. Check the inside of the valve for any foreign matter.
Clean the valve as necessary.
5. Cover the valve to protect it from dirt and take out
the cylinder.
6. Install a new gasket whenever you take out the
cylinder. Use only one gasket and spread a light film
of clean oil on it before installation.
7. Put in the new cylinder. Turn it clockwise until it just
starts to contact the gasket.
8. Tighten the cylinder another half turn (180 degrees).
Don't over
-tighten.
9. Retighten the cylinder clamp.

6-88 Engine Oil with Filter Capacity
Engine Quarts (Liters)
7.2L** 30.0 (28.4)*
8.1L** 6.5 (6.1)
7.8L** 23.8 (22.5 )
6.6L** 14.6 (13.8)
*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).
** Check fill level on the oil indicator after initial fill to
make sure it is actually full. Oil level may vary
depending on vehicle option content.
Fuel Tank Capacity
C4/C5 Models Gallons (Liters). . . . . . . . . . . . . . . . .
Standard* 41 (155.2). . . . . . . . . . . . . . . . . . . . . . . .
Optional 40 (151.4). . . . . . . . . . . . . . . . . . . . . . . . . .
Optional 60 (227.1). . . . . . . . . . . . . . . . . . . . . . . . . .
Optional 80 (302.8). . . . . . . . . . . . . . . . . . . . . . . . . .
C6/C7/C8 Models Gallons (Liters). . . . . . . . . . . . . .
Standard 50 (189.2). . . . . . . . . . . . . . . . . . . . . . . . .
Optional 35 (132.4). . . . . . . . . . . . . . . . . . . . . . . . . .
Optional 50 (189.2). . . . . . . . . . . . . . . . . . . . . . . . . .
Optional
70 (264.8) . . . . . . . . . . . . . . . . . . . . . . . .
Optional75 (283.8) . . . . . . . . . . . . . . . . . . . . . . . .
Optional& 100 (378.5). . . . . . . . . . . . . . . . . . . . . . .
* One 25
-gallon (94.6 L) tank and one 16-gallon
(60.6 L) tank

Two 35
-gallon (132.4 L) tanks
One 25
-gallon (94.6 L) tank and One 50-gallon
(189.2 L) tank
&Two 50
-gallon (189.2 L) tanks

6-91 Service Replacement Part and Filter Recommendations
Engine 7.2L 8.1L 7.8L 6.6L
RPO LG5 L18 LG4 LB7
Spark Plug
ACDelco

41-983
Gap 0.060 inch (1.52 mm)
Torque 14.75 lb. ft. (20.0 Nm)
Oil Filter
CAT

1R0739 ACDelco
PF454GM Part No. 94392475
ACDelco
PF1218
Air Cleaner Donaldson P522606
ACDelco

A1518CC4/C5 Models:
GM Part No. 88937527
C6/C7/C8 Models:
GM Part
No. 88937548***C4/C5 Models:
GM Part No. 88937527
C6/C7/C8 Models:
GM Part No. 88937548***
Fuel Filter
ACDelco


915 Primary**ACDelco
GF626*GM Part No. 94392474 GM Part No. 97256734

7-5
Scheduled Maintenance
The services shown in this schedule up to 100,000 miles
(166 000 km) should be repeated after 100,000 miles
(166 000 km) at the same intervals for the life of
this vehicle. The services shown after 100,000 miles
(166 000 km) should be repeated at the same miles (km)
after those intervals for the life of this vehicle.
Gasoline engine vehicles have a computer that lets you
know when to change your engine oil. This is not based
on mileage, but on engine revolutions and engine
operating temperature. When the computer has
calculated that the oil needs changing, the GM Oil Life
System will indicate that a change is necessary.
The ªFootnotesº at the end of this Maintenance
Schedule further explain maintenance services.
See ªScheduled Maintenance Supplementsº earlier in
this section.
100 Miles (160 km)

Wheel stud nut service. (46)
1,000 Miles (1 600 km)

Wheel stud nut service. (46)

Rear axle air shift motor service.(11)

L18/LB7 Engines Only: Clutch pedal free
travel service. (10)
7,500 Miles (12 000 km)

Gasoline Engine Only: Check Oil Life System.
If engine oil and filter are changed, reset system.
See ªEngine Oilº in the Index. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(6)

Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Wheels and tires service. (15)

Parking brake service (or every 6 months, whichever
occurs first). (8)

L18/LB7 Engines Only: Clutch pedal free
travel service. (10)
10,000 Miles (16 000 km)

DURAMAX Diesel Only: Change engine oil
and filter (or every 12 months, whichever
occurs first). (2)(3)