1
®
Bendix
®
PP-7
™
Trailer Supply Valve
SD-03-3617
EXHAUST
LOCK
WASHER
1/8 P.T.
SUPPLY
NUT & THREAD
CAP SCREW
(18) PLUNGER
RETURN
SPRING
SPIROL
PIN (1)
(12) O-RING
BUTTON (2)
THIN NUT
(17) PLUNGER
HEX LOCK NUT (15)
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
™
valve are
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
™
valve must
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
LOCK
WASHER
CAP SCREW
(13) INLET &
EXHAUST
VALVE
1/4 P.T. DELIVERY
(9) O-RING
1/8 P.T. CONTROL
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)
FIGURE 1 - EXTERIOR
FIGURE 2 - SECTIONAL
