GMC TopKick 2007, Owner'S Manual, Page: 389 / 430

(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 perform this service. See
Part C: Recommended Fluids and Lubricants
on page 397
for 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.
(30) = Change the lubricant. See
Part C: Recommended Fluids and Lubricants
on page 397
.
(31) = Front axle service: Re-pack upper kingpin
roller bearing.
(32) = Air brake service:
•
Inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, chafing,
etc. Inspect drum brake linings for wear or
cracks. Inspect other brake parts at each
wheel, including drums and wheel speed
sensor wiring. 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. Replace air dryer cartridge
only if excessive oil or moisture is present.
A small amount of oil in the system is normal
and should not be considered as a reason
to replace the cartridge.
•
Test air lines for leaks; tighten as needed.
Replace compressor filter.
•
Inspect air parking brake chamber for leaks
and damage. Inspect lines and hoses for
leaks, cracks, chafing, etc. Also check
all attachments for tightness, wear, or damage.
Note: The spring brake section of the rear
brake diaphragms are non-serviceable.
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