TM 9-2330-356-14
(5) Look for damaged brake camshaft.
(6) Look for worn brake hoses or damaged broke
chamber.
(7) Check tightness of bobs which fasten bogie
assembly to trailer frame.
c.
Repair.
Tighten loose bolts. If damage or wear is
evident, notify direct support maintenance.
4-30. Spring Seat Bearings, M967, M969, M970 except
M970 SN TC-0843, TC-0844, and TC-103 thru TC-178.
a. Lubrication Internal. See
figures 3-1 through 3-6,
Lubrication Chart.
b.
Procedure.
Remove plug A on bottom of spring
seat (fig. 3-7) and install a ¼-inch NPT grease fitting.
Apply enough grease to ensure lubrication of the
bearings. Remove grease fitting and install plug.
c.
Replacement of Bearings.
If excessive wear is
evident in the spring seat bearings, notify direct support
maintenance.
Section XII. MAINTENANCE OF BRAKE SYSTEM
4-31.
General, M967, M969, and M970 except M970
SN TC-0843, TC-0844, and TC-103 thru TC-178.
a.
Description. The
semitrailer brakes are air-oper-
ated, wedge-type brakes. Two air chambers and two spring
chambers (fail-safe unit) are assembled on each axle. The
brake chamber forces a wedge between two rollers in the
plunger housing (fig. 4-52). Wedge action causes the
plungers in the actuator assembly to push the brake shoes
against the brake drum.
(1) The brakes are double-actuated. One of the
actuating assemblies is shown in figure 4-52. The brake
chamber is threaded into the wedge bore of the plunger
housing.
(2) The socket in the end of the diaphragm push
rod connects the brake chamber to the wedge rod.
(3) The wedge retracting spring acts as the return
spring for both the wedge and the diaphragm.
(4) Rollers on the wedge head engage slots in the
inner ends of the plungers. The outer end of the plungers
are in contact with the brake shoes.
Figure 4-52. Brake Actuator Assembly (M967, M969, and M970 except M970 SN TC-0843, TC-0844,
and TC-103 thru TC-178).
4-74
Change 3