TM 9-2330-356-14
(7) Connect brake lines.
(8) Make and hold a full pressure application (fall
air tank and apply service brakes). Hand tighten the collet
nut. With a drift and hammer tighten nut 1-teeth or
additional 3/16 of a turn. Release service brakes.
(9) Uncage spring in fail-safe unit.
4-40. Brake Chamber-Fail-Safe Unit
Test and
Replacement, M967A1, M969A1, and
M970A1 including M970 SN TC-0843,
TC-0844, and TC-103 thru TC-178.
fail-safe unit will also be pressurized when the emergeney
line is connected.
b.
Replacement of Fail-Safe Unit.
(2) Release air pressure by opening drain valves on
(3) Tag and disconnect brake hoses from brake
chambers and relay valve.
(4) Remove cotter pin and clevis pin from slack
Figure 4-74. Removing Fail-Safe Air Brake Chamber
adjuster and yoke.
(M967A1, M969A1, and M970A1 including M970 SN
TC-0843, TC-0844, and TC-103 thru TC-178).
(5) Remove two nuts and washers from fail-safe unit
mounting bolts and remove fail-safe unit from bracket.
Slack Adjuster, M967A1, M969A1, and
(6) Install new fail-safe unit to bracket with two
M970A1 mcluding M970 SN TC-0843,
washers and nuts. Do not tighten nuts. Position ports on the
fail-safe unit to aline with brake hoses. Tighten nuts.
Removal.
a.
(7) Connect hoses to brake chamber,
(1) Remove cotter pin and clevis pin securing
(8) Install yoke to adjuster with clevis pin and cotter
pin. Bend back ends of cotter pinto secure.
yoke to slack adjuster.
(9) Manually release spring in fail-safe unit.
(2) Remove retaining ring from end of camshaft.
(3) Using a brass hammer, tap on slack adjuster
lightly until it comes off the camshaft.
Repair of Fail-Safe Unit.
c.
Inspection and Repair.
b.
WARNING
WARNING
DO NOT attempt to repair brake chamber fail-
Dry cleaning solvent P-D-680 is toxic and
safe unit. It is dangerous because of high
flammable. Always wear protective goggles
spring compression. No repair is authorized
and gloves, and use only In a well-ventilated
for fail-safe unit.
area. Avoid contact with skin, eyes, and
clothes, and DO NOT breathe vapors. DO
NOT use near open flame or excessive heat.
The solvent's flash point is 100 "F-138"F
(38C-59C). If you become dizzy while
using cleaning solvent, immediately get fresh
Change 3