TM 9-2330-356-14
(2) Check fittings, valve, and air drain valves for
leaks. Tighten if leaks are found.
(3) Remove blocks from semitrailer wheels.
(M970 installation shown Typical of M967,
M967A1, M969, and M969A1 semitrailers,
except for brake interlock connection on
M970 and M970A1).
a.
Removal.
Test and Adjustment.
a.
(1) Block semitrailer wheels to prevent
movement.
trailer "Emergency" gladhand with gage closest to trailer.
(2) Drain air from reservoir by opening air drain
(2) Attach air supply line to valve end of test
valves on bottom of both air reservoirs.
gage. Air supply can be either a tractor or stationary
source.
(3) If air drain valves are to be replaced, unscrew
and replace with new ones.
(3) Pressurize system. Close valve on test gage
when system is full. Note gage reading. Drain secondary
(4) If rear reservoir is to be replaced, disconnect
(forward) air reservoir by opening drain valve on bottom of
hoses and fittings to emergency relay valve. Relay is
reservoir. When all air has exhausted from secondary
mounted to a nipple on rear reservoir.
system, gage should read 75 psi. If pressure is not correct,
adjust pressure protection valve as follows:
(5) Remove air fittings on each end of reservoir.
Remove two mounting bolts on each end of reservoir and
(a)
Loosen locknut (4) at base of cap.
remove reservoir. If rear reservoir is removed, emergency
relay valve will be removed with it. Remove relay valve by
Turn cap (5) clockwise to increase pres-
(b)
unscrewing from nipple.
sure setting.
Installation.
b.
(c)
Turn cap counterclockwise to decrease
setting.
(1) Install new reservoir, bolt in place and
reconnect fittings. If rear reservoir was replaced, screw
(4) Repeat step (3) until desired pressure is
emergency relay valve onto reservoir nipple before
obtained, then tighten lock nut.
replacing reservoir on frame. Close air drain valves. Refill
with air and check reservoir for leaks.
(5) Remove air system test gage.