TM 5-3805-262-20
7-3. AIR BRAKE SYSTEM MAINTENANCE (CONT)
b. Service Brake Treadle and Valve and Declutch Treadle and Valve (cont).
INSTALLATION
(1)
(2)
(3)
(4)
(5)
(6)
Position treadle and valve on cab deck.
I n s t a l l t h r e e c a p s c r e w s ( 3 ) . T e l l a s-
s i s t a n t t o i n s t a l l a n d t i g h t e n t h r ee
lock washers (2), and nuts (l).
Connect air lines and fittings to
treadle and valve (page 7-82).
If necessary, install double check valve
and stop light switch (page 7-68).
Close air reservoir drain valve.
Reposition cab floor mat.
LEAKAGE TEST
(1)
(2)
(3)
(4)
( 5)
Start engine and operate at idle speed.
Continue to operate engine until air
pressure gage indication on left instru-
ment cluster no longer increases.
Apply parking brake.
Turn off engine. Be sure treadle and
v a l v e i s f u l l y r e l e a s e d.
Apply soap solution on and around bottom
bore of valve body. Watch for bubbles.
I f b u b b l e s a r e s e e n , t h i s i n d i c a t e s a ir
leakage. If there is any air leakage,
replace treadle and valve. Forward de-
fective treadle and valve to direct sup-
port maintenance for repair.
Tell assistant to press treadle completely while you apply soap solution
on and around bottom bore of valve body. Watch for bubbles. If bubbles
are seen, t h i s i n d i c a t e s a i r l e a k a g e . I f t h e r e i s a n y a i r l e a k a g e , r e-
place treadle and valve. Forward defective treadle and valve to-direct
support maintenance for repair.
7-54
