2003 CHEVROLET C/K engine oil

7-23
Body Lubrication Service
Lubricate all exposed surfaces such as door checks, door
lock bolts, lock strike plates, door latches and dovetail
bumper wedges. Where oil holes are provided a dripless
oil can be used. The seat adjusters, seat track, door
weatherstrips and rubber cap bumpers should also be
lubricated.
Part C tells you what to use. More frequent lubrication
may be required when exposed to a corrosive
environment.
Parking Brake Check
Park on a fairly steep hill and hold the vehicle with the
parking brake only. This checks holding ability.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 and the
regular brakes. See ªParking Brakeº in the Index
if necessary.
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.

7-26
Fluid Leaks Check
Check for fuel, coolant, oil or other fluid leaks by
looking at the surface beneath the vehicle after it has
been parked for awhile.
Underbody Inspection
Corrosive materials used for ice, snow removal and dust
control can collect on the underbody. If these materials
are not removed, accelerated corrosion (rust) can occur
on underbody parts such as fuel lines, frame, floor pan
and exhaust system. At least every spring, flush these
materials from the underbody with plain water. Take
care to clean well any areas where mud and other debris
can collect. Sediment packed in closed areas of the
frame should be loosened before being flushed.
Engine Cover Check
Check that the cab's engine cover and seal (if equipped)
are not torn or damaged. Be sure that the cover is
clamped down firmly to the floor.At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
specified in Part C.
Underbody Flushing Service
At least every spring, use plain water to flush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
Tractor Protection (Breakaway) Valve Check
On air brake models, remove, disassemble, clean and
inspect the tractor protection (breakaway) valve.

7-27
Part C: Recommended Fluids and
Lubricants
Fluids and lubricants identified below by name,
part number or specification may be obtained from
your dealer.
USAGE
FLUID/LUBRICANT
Engine Oil
(Gasoline
Engine)Engine oil with the American
Petroleum Institute Certified for
Gasoline Engines starburst symbol
of the proper viscosity. To
determine the preferred viscosity
for your vehicle's engine, see
ªEngine Oilº in the Index.
Engine Oil
(Caterpillar
Diesel Engine)See the Caterpillar
Operation &
Maintenance Manual for engine
oil recommendations.
USAGEFLUID/LUBRICANT
Engine Coolant
(Gasoline
Engine &
DURAMAX
Diesel)50/50 mixture of clean, drinkable
water and use only DEX
-COOL

Coolant. See ªEngine Coolantº in
the Index.
Engine Coolant
(Caterpillar
Diesel Engine)See the Caterpillar
Operation &
Maintenance Manual for engine
coolant recommendations.
Hydraulic Brake
SystemDelco Supreme 11
Brake Fluid
or equivalent DOT
-3 brake fluid.
Windshield
Washer SolventGM Optikleen
Washer Solvent
or equivalent.
Clutch Bearing
LubricantClutch Bearing Lubricant
(GM Part No. 12378484 or
equivalent NLGI #3 consistency).