GMC T-Series 1999, Owner'S Manual, Page: 310 / 344

Scheduled Maintenance (DURAMAX
t
DIESEL)
yellow blue
7-48
(8) = Inspect hydraulic parking brake drum and linings
for wear or cracks and check linkage and adjustment.
Check spring brake actuator and pump for leaks.
Note: The spring brake section of the actuator is
non
-
serviceable.
(9) = Change main oil filter element.
(10) = Check clutch pedal for free travel. Press pedal by
hand until resistance is felt. Free travel should be
maintained at 1.5 to 2 inches (38 to 51 mm) measured at
the clutch pedal pad. Make checks at 3,250 miles
(5 200 km) and 6,500 miles (10 400 km) and then every
6,500 miles (10 400 km) thereafter.
(11) = 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
3,250 miles (5 200 km) and 26,000 miles (41 600 km)
and then every 26,000 miles (41 600 km) thereafter.
(12) = 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. Lubricate transmission and shift linkage, cab
latches and cab hinges, parking brake lever pivot, clevis
pins and linkage, disc brake caliper rails, clutch linkage
and release bearing (if equipped), propeller shaft slip
joint, universal joint, brake camshaft bracket, slack
adjusters, pedal shaft, clutch cross shaft and clutch pedal
springs. Lubricate suspension, axle and steering linkage
more often when operating under dusty or muddy
conditions and in excessive off
-
road use.
(13) = Check steering system:
D Look for damaged, loose or missing parts. 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 service manual.)