TM-9-2320-279-10-2
M977 SERIES, 8x8 HEAVY EXPANDED MOBILITY TACTICAL TRUCKS (HEMTT)
OPERATOR’S MANUAL VOLUME 2 OF 2
DECEMBER 1998
CHANGE 3
TM-9-2320-279-10-2 - Page 31 of 819
1-33. AIR
TM 9-2320-279-10-2
Vehicle Operation Systems (Cont)
Once air pressure in reservoir (2) rises above 75 psi (517 kPa), a valve opens
and allows reservoirs (3, 4, and 5) to be pressurized up to 120 psi (827 kPa). Air
from reservoir (4) goes to the brake treadle valve (10). This air controls the rear
axle service parking brakes (11). Air pressure in this system is shown by the red
needle on the AIR PRESS gage (12). Air from reservoir (3) goes to the brake
treadle valve. This air controls the front axle service brakes (13). Air pressure in
this system is shown by the green needle on the AIR PRESS gage.
The PARKING BRAKE valve (14) controls air from reservoirs (3 and 5) and
applies or releases the rear axle service (parking) brakes. Reservoirs (3, 4, and 5)
are interconnected so that if one reservoir fails. air is supplied to release the rear
axle service (parking) brakes from whichever reservoir is functioning. If air
pressure falls below 60 to 75 psi (414 kPa to 517 kPa), a buzzer will sound and
the AIR indicator (15) will light.
On the M984E1 the front brake actuator valve (16) is used to apply the front
axle service brakes when using heavy-duty winch.
Figure 1-24.
Air System Components location.
1-16
Back to Top
