TM 9-2330-356-14
(5) Install nut on release tool, and tighten until
1
3
2 /2 to 2 /4-inches of release tool is exposed.
(6) Repeat steps (2) through (5) for remaining
fail-safe units.
(7) As soon as air is available to refill the
reservoirs, remove the release tool and nut from each of
the four fail-safe units, and install in mounting hole.
Install plugs in place.
M969, and M970 exept M970 SN TC-0843, TC-0844, and
TC-103 thru TC-178).
(2) Unsnap breather cap from each of the four
fail-safe units (fig. 2-5).
(3) Using a 3/4-inch deep socket wrench (Appen-
dix D), turn the manual release bolt counterclockwise un-
tit brake shoes are released on each drum.
CAUTION
M969A1, and M970A1 including M970 SN TC-0843, TC-
0844, and TC-103 thru TC-178).
Do not leave breather caps off any longer
Operating Towing Vehicle With Semitraller
than necesssary. Water, mud, and other
Coupled
contaminants can harm the operation of the
brake actuator. The vent on the breather cap
a.
Driving. The overall length of the towing vehicle
must beat the lowest location pointing down.
and semitrailer must be kept in mind when passing other
vehicles and when turning. Because the unit is hinged in
the middle, turning and backing are affected. The surge of
(4) As soon as air is available to refill the
the load also affects stopping.
reservoirs, turn the manual release bolt clockwise on each
of the four fail-safe units until bottomed. Snap breather
b.
Turning. When turning corners, remember that
caps in place.
the semitrailer has a shorter turning radius than the tow-
ing vehicle. To make a right turn at a road intersection, the
c. Manual Release (Caging) (M967A1, M969A1, and
towing vehicle must continue forward to about the center
M970A1 including M970 SN TC-0843, TC-0844, and TC-103
of the crossroads, and then turn sharply to the right to al-
low for the shorter turning radius of the semitrailer. lb
brakes when no air is available, use the following prodedure:
back the semitrailer to the right, turn the steering wheel of
the towing vehicle to the left or counterclockwise. The
(1) Block wheels to prevent semitrailer move-
front of the semitrailer will be pushed to the left, and the
ment.
semitrailer wheels will steer to the right.
(2) Remove nut and the release tool from
C.
Stopping. In normal operation, the brakes of the
mounting hole in the fail-safe unit (fig. 2-6).
towing vehicle and those of the semitrailer are applied at
the same time. Brake pressure should be applied gradually
(3) Remove plug.
and smoothly. On steep grades and slippery surfaces, the
semitrailer brakes should be applied first; then the brakes
(4) Insert the release tool into the hole and turn
of the towing vehicle should be applied. This procedure
1
will reduce the possibility of the semitrailer "jack-knifiig".
/4-turn to seat release tool in pressure plate.
Change 3
