TM 5-3805-262-20
3-19. AIR BRAKE SYSTEM TROUBLESHOOTING (CONT)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
5. AIR PRESSURE WILL NOT BUILD UP TO NORMAL (Cont).
Step 3.
Open drain valve on air reservoir and drain air.
Disconnect wire lead from pressure sender terminal and remove pres-
sure sender.
I n s t a l l a n a c c u r a t e , c a l i b r a t e d , a i r p r e s s u r e g a g e i n f i t t i n g f r om
which pressure sender was removed.
Close drain valve on air reservoir.
Start engine and allow air system to build up air pressure.
Compare reading on AIR PRESS gage with reading on calibrated test
gage.
a. If AIR PRESS gage indicates in lower fourth of green area with
test gage indicating 115 psi
5 - 3 9 ).
, replace AIR PRESS gage (page
b. If AIR PRESS
ing 90 to 95
3-129).
6. AIR PRESSURE TOO HIGH OR AIR
gage indicates in red area with test gage indicat-
psi, go to MALFUNCTION 4, step 3 above (page
COMPRESSOR WILL NOT CUT OUT.
Check governor adjustment (page 7-100).
If governor is out of adjustment, adjust (page 7-100).
If governor cannot be adjusted, replace it (page 7-98).
7. AIR COMPRESSOR FAILS TO MAINTAIN SUFFICIENT AIR PRESSURE.
Step 1. Check that air reservoir drain valve is closed tightly.
a . C l o s e d r a i n v a l v e t i g h t l y.
b. If drain valve is closed tightly, go to step 2 below .
3-132
