Preventive Maintenance; Service Checks; Operational And Leakage Tests; Removal And Installation - BENDIX TP-3DC TRACTOR PROTECTION VALVE Manual

4. If the work is being performed on the vehicle's
air brake system, or any auxiliary pressurized air
systems, make certain to drain the air pressure
from all reservoirs before beginning ANY work
on the vehicle. If the vehicle is equipped with an
AD-IS ® air dryer system or a dryer reservoir module,
be sure to drain the purge reservoir.
5. Following the vehicle manufacturer's recommended
procedures, deactivate the electrical system in a
manner that safely removes all electrical power
from the vehicle.
6. Never exceed manufacturer's recommended
pressures.
7. Never connect or disconnect a hose or line
containing pressure; it may whip. Never remove
a component or plug unless you are certain all
system pressure has been depleted.
8. Use only genuine Bendix
components and kits. Replacement hardware,
tubing, hose, fi ttings, etc. must be of equivalent
size, type and strength as original equipment and
be designed specifi cally for such applications and
systems.
9. Components with stripped threads or damaged
parts should be replaced rather than repaired. Do
not attempt repairs requiring machining or welding
unless specifi cally stated and approved by the
vehicle and component manufacturer.
10. Prior to returning the vehicle to service, make
certain all components and systems are restored
to their proper operating condition.
11. For vehicles with Antilock Traction Control (ATC),
the ATC function must be disabled (ATC indicator
lamp should be ON) prior to performing any vehicle
maintenance where one or more wheels on a drive
axle are lifted off the ground and moving.

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-3DC valve should be inspected every 6 months or
1500 operating hours, whichever comes fi rst, for proper
operation. Should the TP-3DC
elements of the operational tests noted in this document,
further investigation and service of the valve may be
required.

SERVICE CHECKS

1. Remove any accumulated contaminants. Visually
inspect the valves exterior for cracks, gouges, or other
physical damage. Replace the valve if physical damage
is excessive.
6
®
replacement parts,
™
valve not meet the
2. Inspect all air lines connected to the valve for signs
of wear or physical damage. Repair/replace as
necessary.
3. Test air line fi ttings for excessive leakage and tighten
or replace as necessary.

OPERATIONAL AND LEAKAGE TESTS

1. Block the vehicles wheels and fully charge the air
system.
2. Place the trailer supply valve in the emergency
position.
3. Disconnect the trailer control line hose coupling. Then
make a service application with either the foot valve or
the trailer control valve and check for leakage at the
hose coupling with a soap solution. Leakage should
not exceed a 1" bubble in 5 seconds (100 SCCM).
4. Release the service application and place the trailer
supply valve in the normal or run position. Connect the
trailer control valve to a test gauge.
5. Make a service brake application and note that service
air pressure is present at the trailer control line hose
coupling.
6. With the ignition on, make and hold a service brake
application and note that the stop lights function.
7. Remove the line at the TP-3DC
control port (TRAC CONT) and plug the end of the line.
Then make a service brake application and check for
leakage at the open tractor control port. Leakage should
not exceed a 1" bubble in 5 seconds (100 SCCM).
8. Reconnect the line to the primary tractor control port,
then disconnect and plug the line at the secondary
tractor control port (TRACT CONT). Then make a
service brake application and check for leakage at the
open tractor control port. Leakage should not exceed
a 1" bubble in 5 seconds (100 SCCM).
If the valve does not function as described; or if leakage is
excessive, repair the valve or replace it at any authorized
parts outlet.
REMOVAL
1. Identify and mark or label all air lines and their
connections to the TP-3DC
the air lines.
2. Remove the TP-3DC
the mounting hardware.
INSTALLATION
1. Install the TP-3DC ™
mounting hardware saved during removal.
2. Reconnect all air lines to the valve using the identifi cation
made during removal.
3. Test all air fi ttings for excessive leakage and tighten as
needed. Also, perform OPERATIONAL AND LEAKAGE
TESTS before placing the vehicle back into service.
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valve primary tractor
™
valve. Then disconnect
™
valve from the vehicle. Retain
valve on the vehicle using the