TM 5-3805-262-20
3-19. AIR BRAKE SYSTEM TROUBLESHOOTING (CONT)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
3. LOW AIR PRESSURE (AIR PRESSURE GAGE INDICATES IN RED ZONE AND LOW AIR PRES-
SURE BUZZER SOUNDS) (Cont).
Step 6.
Disconnect hose connected to check valve.
Remove check valve from elbow.
Connect an air hose connected to a regulated air supply capable
supplying up to 160 psi air pressure to check valve female end.
of
Apply air pressure to check valve; check valve shall not v e n t a i r.
a. If check valve vents air, replace it (page 7-58).
b. If check valve does not vent air, reinstall it and connect hose
to check valve. Go to step 7 below.
Step 7.
Close air reservoir drain valve.
T e l l a s s i s t a n t t o s t a r t e n g i n e.
W i t h e n g i n e o p e r a t i n g , i n s p e c t a i r r e s e r v o i r , f i t t i n g s , a n d h o s es
for air leakage (page 7-56).
a. If a hose is leaking, replace (page 7-58).
b . I f a f i t t i n g i s l e a k i n g , t i g h t e n i t ; i f i t s t i l l l e a k s a f t e r
t i g h t e n i n g , r e p l a c e i t ( p a g e 7 - 5 8 ).
c . I f a i r r e s e r v o i r i s d a m a g e d , r e p l a c e i t ( p a g e 7 - 5 8 ).
d. If fittings and hoses are okay, go to step 8 below.
Step 8.
With engine operating, inspect air compressor lines for air leakage
(page 7-102).
a. If air compressor lines are leaking tighten; if tightening does
no good, replace leaking lines (page 7-106).
b. If air compressor lines are okay, go to step 9 below.
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