BENDIX BW1572 User Manual download pdf

SD-03-3652

Bendix

TP-3

™

Tractor Protection Valve

FIGURE 1

DESCRIPTION

The TP-3

™

(See Figure 1) tractor protection valve is used in

combination with the PP-3

™

trailer supply valve on pre-121

tractors and the PP-7

™

trailer supply valve on post-121

tractors. It contains a passage for trailer supply air and a

service line shut off valve. It is normally mounted behind the

cab with the delivery line from the trailer supply valve

connected into the tractor emergency port and a delivery

line from the brake valve connected to the tractor service

port. The trailer supply and service hoses are mounted in

their respective ports in the TP-3

™

valve. (See Figure 2)

OPERATION

Air from the trailer supply valve passes through the

emergency ports of the TP-3

™

valve to supply the trailer air

system and simultaneously exerts pressure on the end of

the plunger (3). Figure 3. TP-3

™

valves manufactured prior to

June 1970 required approximately 80 psi on the plunger to

open the inlet valve (4) (See Figure 4) which opens the service

line shut off line. Valves manufactured after June 1970 require

approximately 45 psi to open the inlet valve. (Modification

kit 265066 is available to modify old revision TP-3

™

valves to

the later revision 45 psi opening. Field maintenance kit

280858 contains the parts necessary to service both old

and new).

Whenever the pressure from the trailer supply valve drops

below 45 psi the TP-3

™

valve will close the service line shut-off

valve.

PREVENTIVE MAINTENANCE

Important: Review the Bendix Warranty Policy before

performing any intrusive maintenance procedures. A warranty

may be voided if intrusive maintenance is performed during

the warranty period.

TRACTOR

EMERGENCY

PORT

TRAILER

SERVICE

PORT

TRAILER

EMERGENCY

PORT

TRACTOR

SERVICE

PORT

OLD REVISION TYPE TP-3

™

TRACTOR PROTECTION VALVE

OPENING PRESSURE

APPROXIMATELY 80 PSI

O-RING (7)

RETAINING RING (1)

DIAPHRAGM

SEAT (9)

WASHER (8)

PRELOAD

SPRING (2)

DIAPHRAGM (5)

VALVE SPRING (6)

CAP SCREW (3)

INLET VALVE (4)

O-RING (13)

VALVE (4)

RETAINING

RING (1)

O-RING (7)

SEAT

O-RING (12)

VALVE

RETAINER (10)

PLUNGER (3)

CAP SCREW (3)

WASHER (8)

DIAPHRAGM (5)

DIAPHRAGM

SEAT (9)

SPRING (6)

NEW REVISION TYPE TP-3

™

TRACTOR PROTECTION VALVE

OPENING PRESSURE

APPROXIMATELY 45 PSI

RETAINING

RING (14)

EXTERIOR VIEW

1 2 3 4

Summary of Contents

Page 1 - Tractor Protection Valve

1®SD-03-3652Bendix® TP-3™ Tractor Protection ValveFIGURE 1DESCRIPTIONThe TP-3™ (See Figure 1) tractor protection valve is used incombination with the

Page 2 - INSTALLING

2FIGURE 2TRAILERSERVICE LINETRAILEREMERGENCYLINETP-3™TRACTORPROTECTIONVALVENO. 2RESERVOIRBRAKEVALVENO. 1RESERVOIRDOUBLECHECKCOMPRESSORPP-3™CONTROLVALV

Page 3 - ASSEMBLY

3DISASSEMBLYEARLY REVISION 80 PSI OPENING PRESSURE(Figure 1)1. Remove insert retainer ring (1) Figure 4 with Truarc pliers.2. Remove insert assembly.3

Page 4 - THESE INSTRUCTIONS TO AVOID

4GENERAL SAFETY GUIDELINESWARNING! PLEASE READ AND FOLLOWTHESE INSTRUCTIONS TO AVOIDPERSONAL INJURY OR DEATH:When working on or around a vehicle, the