Western Star 47X 2020, Maintenance Manual

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breakage, possibly leading to loss of vehicle con-
trol and resulting in personal injury or property
damage.
Inspect the crossmember(s) and gussets for wear,
cracks, and other damage. If any of these conditions
exist, replace the damaged parts.
Visually check the air spring piston for cracks, chips,
and broken areas. Check the air bag for rips, tears,
and holes. Verify that the air spring assembly does
not leak. If any of these conditions exist, replace the
damaged parts.
Suspension Height Checking
IMPORTANT: Before checking the AirLiner sus-
pension height, make sure there is no load on
the chassis, and the trailer is unhitched.
IMPORTANT: To prevent voiding the warranty
on Barksdale height-control valves, note the fol-
lowing:
•
Do not overtighten the bolts in the Barksdale
height-control valve housing. The bolts should
not be loose, and should not require tightening.
Only if necessary, tighten the valve housing
bolts 45 lbf·in (500 N·cm). Any damage to the
valve housing will void the warranty.
•
Do not attempt to disassemble the Barksdale
valve body or the control lever. There are no
serviceable parts in the valve, and any disas-
sembly will void the warranty.
NOTICE
When removing or loosening a Barksdale height-
control valve from a mounting bracket, always
hold the valve-side mounting studs in place with
an Allen wrench while loosening or tightening the
nuts that attach the valve to the bracket. Because
the mounting studs are threaded into the valve
body, loosening the nuts without holding the
studs can tighten the studs, which can crush the
valve body and damage the valve. Conversely,
tightening the nuts without holding the studs can
back the studs out, causing a separation of the
two halves of the valve body, and possibly a leak.
1. Park the vehicle on a level surface, using a light
application of the brakes. Do not apply the park-
ing brakes. Shift the transmission into neutral,
and build the secondary air pressure to at least
100 psi (690 kPa). Shut down the engine. Have
an assistant chock the tires on one axle only.
2. Mark the location of the front and rear tires on
the floor.
NOTE: The stud bolt that fastens the valve’s
height-control lever to the vertical linkage is ori-
ented correctly when the linkage rod is vertical,
as viewed from the side of the vehicle; see
Fig.
2 . The rod may be on the forward or aft side of
the lever to get it to be vertical.
3. Measure the distance between the left forward-
most axle stop and the suspension as indicated;
see
Table 1 , Table 2 , Table 3 , Table 4 and
Table 5 for an acceptable range of heights for
each suspension.
f320562a 10/05/2016
1 2
3
4
5
1. Valve Mounting Bracket
2. Height-Control Valve
3. Stud Bolt
4. Linkage Rod
5. Axle
Fig. 2, Barksdale Height-Control Valve Installation (side
view) (typical)
Suspension
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