1
SD-03-3653
Bendix
®
TP-4
™
Tractor Protection Valve (Formerly VM-1)
FIGURE 1
EXTERIOR VIEW
SERVICE STOP
LIGHT SWITCH
(SLS) PORT
TRAILER EMERG.
SUPPLY (TES) PORT
TRAILER EMERG. STOP
LIGHT SWITCH (TE-SLS)
PORT
TRAILER SERVICE
SUPPLY PORT (TSS)
PRIMARY CIRCUIT
DELIVERY PORT
(PCD)
MOUNTING
SURFACE
DESCRIPTION
The Bendix
®
TP-4
™
tractor protection valve is used in the
dual air brake system and houses three valves that serve
the trailer and tractor braking system. The valves are:
1.
The trailer service line shut off portion of tractor
protection system which operates in conjunction
with the dash-mounted PP-3
™
trailer supply valve to
manually or automatically close and retain suffi cient air
pressure in the towing vehicle to stop it with its service
brakes.
2.
A double check valve which permits either primary or
secondary circuit air pressure from the dual brake valve
to actuate trailer brakes.
3. A double check valve which permits use of a trailer
control valve to control only the trailer brakes.
In addition to the ports necessary for the function of the
above described valves, the manifold also provides ports
for the installation of the service stop light switch, front
axle limiting control valve, and the TE-1
™
trailer emergency
stop light switch.
Four 23/64" holes are provided for mounting.
FIGURE 2
SECTIONAL
SECONDARY
CIRCUIT
DELIVERY PORT
(SCD)
VENT
11
4
9
10
7
6
5
12
13
14
PIPE PLUG
VENT
8
2
3
16
1
15
