BENDIX PP-7 TRAILER SUPPLY VALVE Manual

®
® ™
Bendix PP-7
LOCK
WASHER
CAP SCREW
FIGURE 1 - EXTERIOR
FIGURE 2 - SECTIONAL
Trailer Supply Valve
NUT & THREAD
1/8 P.T.
SUPPLY
EXHAUST
LOCK
WASHER
CAP SCREW
(17) PLUNGER
(18) PLUNGER
RETURN
SPRING
HEX LOCK NUT (15)
(12) O-RING
(13) INLET &
EXHAUST
VALVE
1/4 P.T. DELIVERY
(9) O-RING
1/8 P.T. CONTROL
FUNCTION AND DESCRIPTION
The PP-7 ™ trailer supply valve provides in cab control for the
tractor protection system and functions in conjunction with
the park control valve. It is responsible for synchronizing the
tractor and trailer parking and emergency brakes.
It is essentially a combination of two non-modulating, on-
off control valves in a single, compact package.
Each of the four pipe tapped ports of the PP-7
identified with cast in, raised letters. The supply and control
ports have 1/8 inch N.P.T.F. dry seal pipe threads while the
delivery and exhaust ports have 1/4 inch N.P.T.F. dry seal
pipe threads.
GENERAL OPERATION
The PP-7 trailer supply valve is a panel mounted, push-pull
operated control valve. The button of the PP-7
be manually depressed, but will automatically pop out and
exhaust if supply air is below 40 p.s.i. Fifty p.s.i. or greater
supply air pressure is required for the button to remain in
BUTTON (2)
SPIROL
PIN (1)
THIN NUT
O-RING (19)
BODY
INLET & EXHAUST
(16) VALVE
RETAINING RING (10)
SEALING RING (3)
O-RING RETAINER (11)
INLET & EXHAUST (14)
VALVE SPRING
SPRING (7)
LOWER BODY
PISTON (6)
O-RING (8)
O-RING (5)
END PLATE (4)
™
valve are
™
valve must
1