(21)= Inspect parking brake drum and linings for wear
or cracks and check linkage and adjustment.
(22)= Wheel bearing service:
•Grease type — Clean, inspect, and lubricate with
the proper wheel bearing grease at designated
intervals or when hubs are removed. SeePart C:
Recommended Fluids and Lubricants on page 6-31.
•Oil-filled type — Some wheel bearings are
lubricated by axle lubricant. When you have oil-filled
hubs, use lubricant identical to that used in the
axle. Lubricant change intervals are the same for
front and rear axles. However, you must maintain
the proper oil level between change intervals.
SeeFront Wheel Bearings with Oil-Filled Hubs on
page 5-81andPart C: Recommended Fluids
and Lubricants on page 6-31.
(23)= Check the air intake system installation to see
that gaskets are seated properly and all hose
connections, fasteners, and other components are tight.
Tighten connections and fasteners or replace parts as
required.
(24)= Evaporative Control System Service, if equipped:
Check all fuel and vapor lines and hoses for proper
connections and correct routing (or every 24 months,
whichever occurs first). Replace parts as needed.(25)= Replace spark plugs. Inspect wires for damage.
Check the wire boot and boot heat shield fit at spark
plugs and coil. Replace parts as needed.
(26)= Check the fuel tank, fuel cap and fuel lines for
damage which could cause leakage. Inspect fuel cap for
correct sealing ability and any indications of damage.
Check fuel cap gasket for even filler neck imprint.
Replace parts as needed.
(27)= Check Exhaust Gas Recirculation (EGR) system
as described in the service manual. SeeService
Publications Ordering Information on page 7-10.
(28)= Inspect Electronic Vacuum Regulator Valve
(EVRV) filter for excessive contamination or plugging.
If needed, clean filter with solution of soap and water, let
dry and install.
(29)= Drain, flush, and refill cooling system. This
service can be complex; you should have your
dealer/retailer perform this service. SeePart C:
Recommended Fluids and Lubricants on page 6-31for
what to use. Inspect hoses. Clean radiator, condenser,
pressure cap, and neck. Pressure test cooling system
and pressure cap. For Caterpillar
®diesel engines,
always refer to the Caterpillar®Diesel Engine
Operation & Maintenance Manual for coolant
recommendations and change intervals.
6-23
(33)= Clean and lubricate air brake automatic slack
adjuster. Check pushrod travel and auto adjustment
operation. Have serviced if needed.
(34)= Air brake chamber service: Check operation,
mounting clamps, and air lines and check for leaks.
(35)= Trailer brake hand control valve service: Check
operation; lubricate cam and follower.
(36)= Tighten the wheel stud nuts to the specified
torque values at 100 miles (160 km). Thereafter, tighten
them 1,000 miles (1 600 km) after each time the wheel
is removed. SeeTightening the Wheel Nuts on
page 5-86.
(37)= Inspect and clean any accumulated dirt, gravel,
or other foreign objects from the valves and valve boots
as needed. Using light oil, lubricate brake pedal to
brake application valve linkage components. Check any
rubber boots for cracks, holes, or deterioration and
replace if necessary.(38)= Estimated minimum. Actual mileage depends on
fuel and oil consumed.
(39)= If the vehicle has the Isuzu diesel engine and is
used primarily for long trip, highway service, change
the engine oil and filter every 18,000 miles (28 800 km),
or every 12 months, or every 750 hours of engine
operation, whichever occurs first.
(40)= Make sure any safety belt reminder light and
safety belt assemblies are working properly. Look
for any other loose or damaged safety belt system parts.
If you see anything that might keep a safety belt
system from doing its job, have it repaired. Have any
torn or frayed safety belts replaced.
6-25
