Bendix Commercial Vehicle Systems TP-5 User Manual

®

Bendix® TP-5™ Tractor Protection Valve

DESCRIPTION

SD-03-3655

The Bendix® TP-5™ tractor protection valve is a panel or cross
member mounted unit designed to replace the Bendix® TP-3®
valve plus two additional double check valves and quick
release functions. It may be used in conjunction with the
Bendix® MV-3® module or independently. It contains a service
line shut-off valve with exhaust function, a service line quick
release valve and two double check valves.

OPERATION

The function of the TP-5™ valve is to receive all pneumatic
signals pertinent to the operation of the trailer brake system,
transmit the same to the trailer and also to protect the
tractor air supply in case of separation of the connecting
lines to the trailer.

TRACTOR PROTECTION PORTION

Air from the trailer supply control valve in the cab, such as
the MV-3® module, enters at the trailer supply delivery port
and passes out the trailer supply port and simultaneously
acts upon the service line shut-off piston moving the
service line inlet valve off its seat and opening the service line

3/8" PTC

REAR SERVICE

1/4" PTC

STOP

LIGHT

SWITCH

3/8" NPT

TRAILER CONTROL

FIGURE 1 - BENDIX® TP-5™ TRACTOR PROTECTION
VALVE EXTERIOR

1/2" NPT
TRAILER
SERVICE

3/8" NPT

FRONT SERVICE

1/2" NPT

TRAILER

SUPPLY

EXHAUST

FROM TC VALVE

STOP LIGHT

SWITCH

FROM REAR

SERVICE

FIGURE 2 - BENDIX® TP-5™ TRACTOR PROTECTION VALVE SCHEMATIC DIAGRAM

TO TRAILER

SERVICE

SERVICE

LINE QRV

FROM FRONT

SERVICE

VENT

TO TRAILER

SUPPLY

(EMERGENCY)

FROM TRAILER

SUPPLY VALVE

(E.G. MV-3® MODULE)

SERVICE LINE

SHUT-OFF

PISTON

1

O-RING

(4)

DIAPHRAGM

(1)

O-RING

(3)

INSERT

O-RING

(5)

(9)

O-RING

(7)

CAP
NUT
(13)

RETAINING

RING

(15)

SPRING

(16)

VALVE

(2)

O-RING

(6)

O-RING

(5)

O-RING

(7)

EXHAUST

CHECK

VALVE

DIAPHRAGM

(8)

#6

TORX/

PN

SCREW

(17)

COVER

(18)

O-RING

(4)

FIGURE 3 - BENDIX® TP-5™ TRACTOR PROTECTION VALVE
END SECTIONAL VIEW

CAP
NUT

(10)

O-RING

(7)

CAP
NUT

(11)

DOUBLE

CHECK

SHUTTLE

passage (see Figure 2). With common air to the supply side
and service side of the manifold the valve should open at
approximately 45 psi.

If the Bendix

®

MV-3® tractor supply valve is manually or
automatically moved to the exhaust position, the service
line shut-off valve will close at approximately 10 psi and
the exhaust passage in the plunger will vent the trailer
service line.

DOUBLE CHECK VALVES

The two double check valves in the Bendix® TP-5™ valve,
as seen in schematic view Figure 2, serve to pick up the
highest pressure service signal from either the tractor front
brake circuit, rear brake circuit or TC valve signal, operating
the trailer brakes accordingly. The stop light switch port
also picks up this signal and actuates the stop light switch.

SERVICE LINE QUICK RELEASE VALVE

The trailer service line port is located in the cover, as seen
in Figure 3. This cover also houses a quick release valve.
Diaphragm (Item 1 in Figure 3) seals off the exhaust port
on application and upon release of service line application,
permits the trailer service line air to exhaust through the
exhaust port, thus permitting faster release times for trailer
brake release.

CAP NUT

DOUBLE

(9)

CHECK

GUIDES

(14)

FIGURE 4 - BENDIX® TP-5™ TRACTOR PROTECTION VALVE
SIDE SECTIONAL VIEW

SERVICE LINE

SHUT-OFF

PISTON

(19)

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.

No two vehicles operate under identical conditions; as a
result, maintenance intervals may vary. Experience is a
valuable guide in determining the best maintenance interval
for air brake system components. At a minimum, the TP-5
valve should be inspected every 6 months or 1500 operating
hours, whichever comes fi rst, for proper operation. Should
the TP-5™ valve not meet the elements of the operational
tests noted in this document, further investigation and
service of the valve may be required.

A maintenance kit is available under part number 289061.
For the latest service parts and kits, refer to the Bendix
Quick Reference Catalog (BW1114) available for order or
download at www.bendix.com.

SERVICE CHECKS

OPERATING AND LEAKAGE CHECKS

1. Charge the air brake system to governor cut-out, block
the wheels, and place tractor protection control valve
in the emergency position.

(12)

™

2