Spicer TPCS (Tire Pressure Control System) Service Manual - Manual (Page 29)

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Note the following important points while performing
this procedure:
• If trailer is equipped with a moveable tandem,
(is adjustable in length), be sure to provide
enough extra air hose to allow full adjustment
of trailer. See Figure 9.
• Do not connect the trailer air line to anything
other than the trailer mating Tire Pressure
Control System connector.
• Front and rear trailer axle wire braid hoses
must be equal length, see Figure 16.
• For proper hose lengths, see Figure 9.
• For the Pneumatic Control Unit to trailer
connection, see Figure 15.
1. Turn off the vehicle’s ignition and engine.
Warning: Drain off air from the wet tank before
removing any fittings!
2. Refer to Figure 16 and remove the damaged or
broken components.
Note: Refer to the following steps as required to
replace individual components. For trailers equipped
with a bulkhead, start at step 3. For trailers without
bulkheads, start at step 6.
3. Install the quick disconnect for trailer air supply to
the bulkhead. (Refer to the brake system’s air-
supply gladhand for similar installation.)
4. Position the bulkhead fitting to install from interior
side of the frame. Connect one end of the 5 /
16
" wire
braid hose, which will be routed to the rear axles of
the trailer, to the bulkhead fitting. Install into the
frame.
5. Install a section of 5 /
16
" wire braid hose between the
front of the bulkhead fitting and the tractor quick
disconnect. (Refer to the brake system’s air supply
lines for similar installation.)
6. For trailers without bulkheads, install 5 /
16
" wire
braid hose into the quick disconnect fitting using
the appropriate fittings.
7. Run the air supply to the non-drive axles in the
same manner as the existing air brake supply lines.
8. Locate the protected position for the union Tee
midway between the two axles. Connect 5 /
16
" air
supply line from the front of trailer to union Tee.
Be sure to allow adequate slack in supply line for
trailer adjustments.
9. Install 37° flare fittings into the four flange connec-
tor nuts on top of the axles. Point the ends inward
toward the center of the axles. Install equal
lengths of
5 /
16
" braid hoses (with a 3 /
8
" 37° female
fitting) between 37° flare fittings and the union
Tees. Mount the 37° flare union Tees to the center
of each axle housing. Use cable ties to secure Tees
to the axle.
10. Using existing lines for guides and securing points,
run wire braid hose between rear axle union Tee
and front axle union Tee.
11. Using compressed air, clean replacement air line
and check for obstructions.
Note: Allow sufficient length for axle articulation.
12. If needed, repeat the previous step for the rear
axle. Be sure to use equal length hose for each
axle.
13. Inspect entire trailer installation, and install cable
ties to secure the assembly every 18" or less.
14. Start the vehicle and test the Tire Pressure Control
System.
Pneumatic Service
Trailer Axle
Pneumatic Replacement
!