Page 257 of 376

Replacing Brake System Parts
The braking system on a vehicle is complex. Its many
parts have to be of top quality and work well together if
the vehicle is to have really good braking. The vehicle
was designed and tested with top-quality brake parts.
When parts of the braking system are replaced — for
example, when the brake linings wear down and new
ones are installed — be sure to get new approved
replacement parts. If this is not done, the brakes might
not work properly. For example, if someone puts in brake
linings that are wrong for the vehicle, the balance
between the front and rear brakes can change — for the
worse. The braking performance expected can change in
many other ways if the wrong replacement brake parts
are installed.
Hydraulic Brake Pads
Brake pad lining life will vary depending on
vehicle application, working environment, equipment
maintenance, and style of driving. The brake pad lining
wear rate has to be monitored for individual driving
habits — original equipment linings have mechanical
wear indicators to help with this. When down to the last
10% of the brake lining, the brake lining wear indicator
rubs on the rotor, causing a scratching or chirping
sound. When this sound is heard, service to the brake
pads is needed. SeeScheduled Maintenance on
page 6-5.
Aftermarket brake linings might not meet the same
stringent requirements as the original equipment linings.
Using aftermarket brake linings can affect braking
performance, pedal feel, noise, and lining wear.
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Page 261 of 376

Item Number Item Remarks
4 Pivot Points and Hinges Apply chassis lubricant.
5 Pivot Points and Hinges Apply chassis lubricant.
6 Slack Adjuster** One fitting.
7Brake Cam Roller Pins at interface of pin
and shoe**Apply engine oil.
8 Front Steering KnucklesOne 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.
12 Clutch Release Bearing* Cup or fitting.
13 Battery Terminal (except “ST” type) Keep coated with petroleum jelly.
14 Transmission Fill to level of filler plug.
15 Propshaft U-JointsLubricate with GM Part No. 1051344 Wheel Bearing
Lubricant.
16 Parking Brake Clevis Pin$ Apply chassis lubricant.
17 Parking Brake Lever Pivot*, $ Apply chassis lubricant.
18Clutch Release Cross Shaft, Master
Cylinder$Apply chassis lubricant, fill to 1/4 inch (6 mm) below
opening.
19 Release Bearing, Clutch Cross Shaft Two fittings, apply chassis lubricant.
20 Clutch Release Fork Two fittings.
* Applies to some vehicles.
** Applies to air brakes only.
$ Applies to hydraulic brakes only.
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Page 335 of 376

(4)= Applies to vehicles sold in the United States and is
recommended for vehicles sold in Canada.
(5)= Check fluidlevel in brake master cylinder, power
steering pump, front and rear axles, transmission, and
hydraulic spring parking brake pump (if equipped). A low
fluid level in the brake master cylinder can indicate worn
brake linings and should be checked accordingly.
(6)= Inspect brake lines and hoses for proper hook-up,
binding, leaks, cracks, chafing, etc. Inspect disc
brake pads for wear and rotors for surface condition.
Inspect caliper assemblies. Check brake pedal for
excessive free play or travel (or every 6 months,
whichever occurs first) and have serviced if needed.
Check brakes more often if driving habits and conditions
result in frequent braking.
(7)= Check for filter ash, sensor adjustment, and
sensor hose restriction. Clean as needed. This service
can be complex; you should have your dealer/retailer
perform this service.
(8)= This vehicle has the Engine Oil Life System. This
system will show you when to change the engine oil
and filter — usually between 3,000 miles (5 000 km) and
7,500 miles (12 000 km) since your last oil change.
Under severe conditions, the indicator may come
on before 3,000 miles (5 000 km). Never drive your
gasoline engine vehicle more than 7,500 miles
(12 000 km) or 12 months without an oil and filter
change.Remember to reset the Engine Oil Life System
whenever the oil is changed. For more information, see
Engine Oil Life System (Gasoline Engine) on page 5-35
orEngine Oil Life System (DURAMAX/Isuzu Diesel
Engines) on page 5-36orEngine Oil Life System
(Caterpillar Diesel Engine) on page 5-38.
(9)= This vehicle has the Engine Oil Life System. This
system will show you when to change the engine oil
and filter — usually between 3,000 miles (5 000 km) and
15,000 miles (24 000 km) since your last oil change.
Under severe conditions, the indicator may come
on before 3,000 miles (5 000 km). Never drive your
diesel engine vehicle more than 15,000 miles
(24 000 km), or 12 months, or 750 engine hours,
without an oil and filter change.
Remember to reset the Engine Oil Life System
whenever the oil is changed. For more information, see
Engine Oil Life System (Gasoline Engine) on page 5-35
orEngine Oil Life System (DURAMAX/Isuzu Diesel
Engines) on page 5-36orEngine Oil Life System
(Caterpillar Diesel Engine) on page 5-38.
(10)= Inspect rear axle air shift motor for fluid leaks.
Remove plug to check fluid level. Inspect air lines
and hoses for proper hook-up, binding, leaks, etc.
Inspect at 1,000 miles (1 600 km) and 22,500 miles
(36 000 km) and then every 22,500 miles (36 000 km)
thereafter.
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(11)= Chassis Lubrication Service: Lubricate all grease
fittings in front suspension, front axle, and steering
linkage. Do not lubricate kingpin bushings with air
pressure equipment; instead, use a hand grease gun to
ensure complete purge and eliminate sealer cap
distortion. Front axle tie rod ends, both upper and lower
kingpin fittings, and both steering linkage relay rod ends
should be greased with the vehicle loaded on the ground
and wheels turned straight ahead, not with the vehicle on
a hoist. Apply kingpin bushing lubricant to both upper and
lower kingpin grease fittings until new lubricant purges
from between the upper shim pack and thrust bearing.
Lubricate transmission and shift linkage, hood latches
and hood hinges, parking brake lever pivot, clevis pins
and linkage, disc brake caliper rails, clutch linkage and
release bearing (if equipped), bearing pads, propshaft
universal joints, brake camshaft bracket, slack adjusters,
pedal shaft, clutch cross shaft, clutch pedal springs, and
clutch cable bushing at transmission. Lubricate
suspension, axle, and steering linkage more often when
operating under dusty or muddy conditions and in
excessive off-road use. Frequently power-washed
vehicles will require more frequent lubrication.(12)= Check steering system:
•Look for damaged, loose, or missing parts. Inspect
the steering linkage relay rod and tie rod ends for
looseness or lack of lubricant. Also look for
parts showing signs of wear or lack of lubrication.
Replace parts as needed. Also check steering gear
mounting bolts, pitman arm nut, gear housing
upper cover and side cover attaching bolts, steering
column mounting bolts and cardan joint clamp
bolts; tighten if necessary. See the service manual.
•Inspect power steering hoses, tubes, and fittings for
leaks. Hoses and lines must not be twisted, kinked,
or tightly bent. Make sure clips, clamps, supporting
tubes, and hoses are in place and properly secured.
•Check steering gear for leakage around pitman shaft
and housing. If leakage is evident (lubricant oozing
out, not just oily film), leak should be corrected
immediately.
(13)= Check front and rear suspension. Look for
damaged, loose, or missing parts or parts showing signs
of wear or lack of lubrication. Replace parts as
needed.
6-22