freightliner 108SD 2021, Driver Manual

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two top leaves, a loss of vehicle control could
occur. Failure to replace a damaged spring assem-
bly could cause an accident resulting in property
damage, serious personal injury, or death.
1. Inspect the forward and rear spring brackets for
wear, cracks, and other damage. If any of these
conditions exist, replace the damaged bracket(s).
See
Group 32 of the 108SD and 114SD Work-
shop Manual for instructions.
WARNING
Replace worn, cracked, or damaged spring
brackets. Failure to do so could result in bracket
breakage, possibly leading to loss of vehicle con-
trol and resulting in personal injury or property
damage.
2. Inspect the crossmember(s) and gussets for
wear, cracks, and other damage. If any of these
conditions exist, replace the damaged parts. See
Group 31 of the 108SD and 114SD Workshop
Manual for instructions.
3. 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 condi-
tions exist, replace the damaged parts. See
Group 32 of the 108SD and 114SD Workshop
Manual for instructions.
Freightliner AirLiner Component
Inspection and Operation Check
WARNING
Inspect the components and check their operation
as described below. Failure to perform these in-
spections and checks could result in separation of
worn suspension components and loss of vehicle
control, possibly causing personal injury or death,
or property damage.
1. Chock the front tires. Raise the rear of the ve-
hicle so the tires just clear the ground and the
suspension is fully extended. Place safety stands
under the vehicle frame.
2. Squeeze all air springs to check for complete
deflation.
3. Inspect the air spring piston for cracks, chips,
and broken areas. Check the air bag for rips,
tears, and holes. Verify that the air spring assem-
bly does not leak.
4. Check the axle connection welds (beam seat to
equalizing beam) and axle adapter to axle for
cracks. If welds are cracked, grind them out and
reweld the parts observing the welding precau-
tions given in
Group 31 of the 108SD and
114SD Workshop Manual .
5. Move the axle up and down while checking for
signs of looseness due to worn parts at the front
pivot connections. Replace any worn parts.
6. Inspect the shock absorbers for oil leaks and
worn rubber bushings. Replace the shock ab-
sorbers and/or rubber bushings if wear or dam-
age is noted.
7. Inspect the stabilizer bar, if so equipped, for ir-
regular bushing wear or cracks in the brackets.
The stabilizer bar is optional on 10,000- and
15,000-pound AirLiner suspension systems.
8. Remove the safety stands and lower the rear of
the vehicle to the ground. Run the engine until
air pressure of at least 100 psi (689 kPa) is
maintained throughout the system.
9. Check that all air springs are inflated.
Freightliner AirLiner Control Rod
Check
NOTE: The Freightliner AirLiner Suspension is
manufactured at numerous weight ratings. The
control rod on the 46,000-pound-rated suspen-
sion is larger, and is fastened differently than on
other applications.
1. Without disconnecting the control rods, use your
hand to attempt to move each of the control rod
ends up, down, in, and out. If there is any move-
ment, examine the control rods for wear or dam-
age. Replace if necessary.
2. Inspect the rubber bushings for cracks or cuts.
3. Check for any shifting of the barpin.
4. Check for cracks in the metal components and
welds.
Ride Height Valve Check
IMPORTANT: Before checking the AirLiner sus-
pension height, make sure there is no load on
the chassis, and the trailer is unhitched.
Suspension
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