TM-9-2320-272-23-1
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; FIELD MAINTENANCE MANUAL; VOLUME 1 OF 5
SEPTEMBER 2012
TM-9-2320-272-23-1 - Page 1125 of 1313
SECONDARY AIR SYSTEM FAILS TO MAINTAIN PRESSURE (NO MAJOR LEAKS, AIR CAN BE HEARD
ESCAPING INTO AIR INTAKE STACK, PARKING BRAKE APPLIED) - Continued
STEP
3.
IS PROPER AIR PRESSURE AT SERVICE BRAKE PEDAL VALVE SECONDARY AIR SYSTEM DELIVERY
PORT?
a.
Stop engine and open all draincocks until brake system air pressure is vented.
b.
Close all draincocks.
c.
Disconnect pressure gauge from vehicle and return air line to original condition.
T0291DAA
Adapter Fitting
Transducer
Figure 3.
Service Brake Pedal Valve.
d.
Disconnect secondary pressure gauge air line from pedal valve.
e.
Connect adapter fitting to pedal valve.
f.
Connect pressure gauge to adapter fitting.
g.
Starts engine.
h.
Monitor air pressure on pressure gauge.
i.
After 5 minutes, pressure gauge should read 90 to 130 psi.
TM 9-2320-272-23-1
0133
0133-6
Back to Top
