TM 9-2330-294-14
is not necessary to remove the non-pressure
housing assembly portion of the fail-safe
Replacement
chamber assembly. Refer to paragraph 4-33
for removal of fail-safe chamber assembly.
a Inspection. With air hose couplings connected
(1) Manually compress fail-safe unit power
to towing vehicle and brakes applied, coat brake air
spring by following procedure in paragraph 4-30d.
chamber housing flanges and connections with
(2) Vent air pressure in accordance with
soapy water. Check for leakage. No leakage is
permissible.
(3) Disconnect air lines and tag for iden-
CAUTION
tification at installation.
Do not overtighten clamp cap screws, as
(4) Remove nut and cap screw securing clamp.
flanges will become distorted and cause
(5) Spread clamp, taking care not to damage it,
additional air leakage.
hold diaphragm on the non-pressure half and remove
If leakage is found at flanges, tighten air chamber
fail-safe unit.
clamp cap screws evenly. If leakage is found at
c. Repair. Repair of fail-safe housing assembly
connections, tighten fittings. With brakes applied,
should be accomplished by direct support main-
listen at air chamber for venting of air. After initial
tenance personnel.
brake application forces out a small amount of air, no
d. Installation. Replace fail-safe unit and install
air should be expelled. If air continues to exhaust,
in reverse order of removal (b above). Replace
remove fail-safe unit in accordance with b below and
diaphragm if rubber at sealing area is damaged or
check air chamber housing diaphragm for puncture,
has become set. Be sure to manually release fail-
cracks or other damage.
safe unit power spring when installation is completed
b. Removal.
(para 4-30d ).
NOTE
This procedure should be used only when it
Change 1
4-46.1 /(4-46.2 blank)
