Follow the tire manufacturer's
recommended cold inflation pressure for
the tire size, load range (ply rating) and
steer axle loading typical for their operation
(each steer axle tire equals ½ steer axle
loading).
Special applications may warrant a setting
based on experience with the type of tire
operating loads and conditions. Radial tires
are more sensitive to toe-in setting than
bias ply tires. Fine tuning school bus
alignment to line-haul truck standards
does not drastically improve tire tread life.
STEERING SYSTEM
INSPECTION
WARNING: Failure to maintain the
steering system in proper condition can
cause reduced steering ability resulting
in property damage, personal injury or
death.
Note: Have any steering problems
immediately corrected by a qualified service
technician.
Ask your service technician to examine the
steering mechanism. Only minor
adjustments may be necessary.
Regular inspections should include:
• Checking the tie rod, drag link end
clamp bolts and ball joints for proper
tightness.
• Checking for installation and spread of
cotter pins and tightness of nuts at
both ends of the tie rod and drag link.
• Checking that the pitman arm (steering
arm at steering gear) mounting is tight
and locked. Check system for leaks or
hose chafing. Repair immediately, if
necessary. •
Maintaining proper steering gear and
power steering pump lubricant levels.
• Checking steering column joint bolts
and steering linkage, particularly for
body-to-chassis clearance.
Steering Column Joint Bolts
As a good maintenance practice, check
steering column joint bolt tightness every
60,000 mi (96,000 km)
or annually,
whichever occurs first. Do not overtighten
the bolts.
Hydraulic System
Whenever draining and refilling the power
steering's hydraulic system for any reason,
bleed air from the system before returning
the vehicle to service. Failure to bleed the
hydraulic system properly can result in
degradation of power system performance.
Consult an authorized dealer who is aware
of the proper procedures for filling and
bleeding the system.
SUSPENSION SYSTEM
INSPECTION
Note: Do not adjust air suspension height
to any setting other than the specified
setting. Altering the height setting changes
the driveline angle and may result in
unwarrantable component damage, such
as transmission component damage.
Verify drive axle air suspension height and
height control valve performance at engine
oil change intervals.
Periodically check:
• Condition of spring leaves for evidence
of fatigue, bending or breakage.
• Condition of suspension mounting
brackets and bushings.
• Torque rod mounting fasteners for
tightness.
252
F650750 (TBC) , enUSA, Edition date: 202010, Second-Printing Maintenance
