BENDIX BW1438 Manuel D’Utilisation

Page de 6
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