TM 9-2330-356-14
(2) Clean groove in body. Partially collapse
(4) Install seal and washer, slide camshaft part
packing ring with fingers and put one side of packing ring
way through spider, and install second seal and washer on
flange into groove. Use a blunt-ended tool to push ring in
camshaft in order shown.
place. The packing ring must lie flat with no twists or
(5) Expand retaining ring and slide over
bulges.
camshaft. Install camshaft and lock in place with retaining
c. Repair.
ring.
(1) Tighten screws holding air line clips.
(6) Install slack adjuster (para 4-41).
(7) Install brake shoes (para 4-34).
(2) Tighten fittings if leaks are found. Replace
lines or fittings if leaks cannot be stopped (para 4-48).
(8) Install wheels and drum assembly (para 4-49).
(9) Adjust slack adjuster (para 4-34).
Test.
a.
(10) Lubricate camshaft (fig. 3-18).
(1) When the brake pedal or trailer hand brake
lever of the towing vehicle is depressed or applied, air is
Lines and Fittings
delivered through the service line to the emergency relay
valve.
Test.
a.
(2) The emergency relay valve releases air from
(1) Connect air brake hose couplings from
the primary brake reservoir to the brake chambers to set
towing vehicle to semitrailer (fig. 2-1). Apply brakes and
the brakes.
coat hose couplings, connectors, and fittings of emergency
and service lines with soap and water solution. No leakage
(3) Engage the service brake and apply soapy
is permissible.
water to exhaust port on top of the emergency relay valve.
If there is leakage, replace the relay valve.
(2) Check air lines and fittings for restrictions
caused by dents or kinks.
(4) Apply and release the service brake several
times. Listen for immediate response from the relay valve.
(3) Coupling damage is usually caused by worn,
If there is hesitation in brake application and release,
damaged, or improperly installed packing ring. Install new
replace the relay valve.
packing ring to stop leaks (para 4-43).
Replacement.
b.
Packing Ring Replacement (Fig. 4-77).
b.
(1) Block semitrailer wheels to prevent move-
(1) Remove packing ring by prying out of
ment.
coupling with screwdriver or other suitable tool.
(2) Disconnect towing vehicle and/or air brake
lines and open air drain valves on bottom of both air
resevoirs (fig. 4-79). Leave open while replacing valve.
(3) Tag air lines for identification at assembly.
Disconnect hose and tube fittings from valve. Remove
double check valve and unscrew valve from nipple in
reservoir.
(4) Screw new valve onto nipple. Install double
check valve, and reconnect hose and tube fittings.
(5) Close air drain valves in both reservoirs.
Connect towing vehicle and fill the reservoir.
(6) Test service brakes and parking brakes
(7) Remove blocking from semitrailer wheels.
