BENDIX TC-2 TRAILER CONTROL BRAKE VALVE User manual

1
DESCRIPTION
The TC-2™brake valve is a hand operated control valve
which features a graduated control of air pressure. The
most common application is the control of trailer brakes
independent of tractor brakes; however, the valve may be
remotelyoperatedtypevalveisconnectedtotheoperating
handle by a linkage rod.
TheTC-2™brakevalveisnotintendedforuseasa parking
control valve and should not be used for that purpose.
OPERATION
APPLYING
Whenthehandleoractuatingleverismovedinaclockwise
directionfromthereleasedposition,forceisexertedonthe
pressure graduating spring through the action of the cam
and cam follower. The force of the spring on the piston
causes it to move down.
The exhaust seat, which is in the center of the piston,
contactstheexhaustvalveandcloses theexhaustpassage
in the piston. The continued downward movement of the
piston moves the inlet valve off its seat. Reservoir air
pressure flows by the open inlet valve and out the delivery
port.
SD-03-813
Bendix®TC-2™Trailer Control Brake Valve
HOLDING
The air pressure that flows by the open inlet valve also
becomes effective on the bottom area of the piston. As
the force of the air pressure beneath the piston balances
the force of the depressed graduating spring above, the
pistonliftsslightly and the inlet valve returns to its seat.The
exhaust valve remains seated so the flow of air through
the valve is stopped and air pressure in the service line
is held.
FIGURE 1 TC-2™TRAILER CONTROL BRAKE VALVE TYPICAL PIPING DIAGRAM
TC-2™BRAKE
VALVE
CONTROLVALVE
RESERVOIR
BRAKE
VALVE
COMBINATION STOP LIGHT SWITCH
AND DOUBLE CHECK VALVE
TRACTOR
PROTECTION
VALVE EMERGENCY HOSE
SERVICE HOSE
FIGURE 2 EXTERIOR VIEW

2
RELEASING
When the handle or operating lever is moved in a
counterclockwise direction the force above the piston is
decreased.Theair pressure beneathwillthenlift the piston,
moving it away from the exhaust valve. With the exhaust
passage open, air pressure in the service line will exhaust
out the exhaust port of the valve.
PREVENTIVE MAINTENANCE
Important: Review the warranty policy before performing
any intrusive maintenance procedures. An extended
warranty may be voided if intrusive maintenance is
performed during this period.
Because no two vehicles operate under identical
conditions, maintenance and maintenance intervals will
vary.Experienceisa valuable guide indeterminingthebest
maintenance interval for any one particular operation.
Visuallycheck forphysicaldamagetothebrakevalvesuch
as broken air lines and broken or missing parts.
Every 3 months, 25,000 miles or 900 operating hours
perform Operating and Leakage Tests.
SERVICE CHECKS
OPERATING TEST
Connect an accurate test gauge to a delivery port. When
thehandleismovedto the fully applied position, the gauge
shouldregister full reservoir pressure. NOTE: Somevalves
may be preset to deliver lower than reservoir pressure;
however,the standardvalvesgenerally usedontractors are
settodeliverfullreservoirpressure.Intermediatepositions
should deliver proportional intermediate pressures. Upon
release, the gauge should immediately register zero.
LEAKAGE TEST
Locate the exhaust port or exhaust line and apply a soap
solution. (It is common practice to connect a line from
the valve exhaust port to a location remote from the
immediate driver’s area.) With the valve in the released
position, exhaust leakage should not exceed a 1" bubble
in 5 seconds (100 sccm).
With the valve fully applied, leakage at the exhaust
should not exceed a 1" bubble in 3 seconds (175 sccm).
If the valve does not function as described or leakage is
excessive, it is recommended that it be replaced with a
neworremanufacturedunit,orrepairedwithgenuineparts
available at Bendix outlets.
REMOVING AND INSTALLING
REMOVING
1. Block and hold vehicle by means other than air
brakes.
2. Drain air brake system.
3. Ifremote-operatedtypevalve, disconnect the operating
mechanism.
4. Disconnect air lines from valve.
5. Remove mounting clamp bolts, clamp, and then valve.
INSTALLING
1. Check and clean air lines to valve.
2. Operating mechanism for remote type should be
checked functionally and for proper adjustment.
3. Mount valve with clamp and mounting bolts.
4. Tighten mounting bolts evenly to approximately 200
inch pounds torque (3/8-16 bolt torque 180-220 inch
pounds.)
5. If remote type valve, connect operating mechanism.
DISASSEMBLY
HANDLE OPERATED VALVE
1. Drive out the spirol pin and remove the handle, head,
and head seal o-ring.
2. Remove handle o-ring.
3. RemoteOperatedTypeValve:Removesetscrew, head
and head seal o-ring.
4. Remove adjusting ring lock washer.
5. Removecapscrewsthatholdbody and cover together;
separate cover from body.
6. Remove gasket and graduating spring.
7. Remove cam and cam follower from cover.
8. Unscrew and remove adjusting ring.
9. Remove piston and piston return spring from body.
10.Remove piston o-ring.
11. Remove inlet and exhaust insert screws and lock
washers, then insert and o-ring seal.
12.Theinletandexhaustvalve insert can bedisassembled
if desired or necessary.
13.Insert some object such as a cap screw in the supply
port to hold the inlet valve on its seat.
14.Depress the exhaust valve guide and spring; remove
the exhaust valve.
15.Remove stem with inlet valve from inlet seat and
remove inlet valve from stem.
CLEANING AND INSPECTION OF PARTS
1. Clean all metal parts in mineral spirits.
2. Wipe rubber parts clean.
3. Inspect valve seats for nicks or burrs.
4. Check all springs for distortion, cracks, and
corrosion.
5. All rubber parts should be inspected for wear or
deterioration.
6. Replace all parts not considered serviceable during
their inspection with genuine Bendix replacement
parts.

3
Adjusting Ring
Adjusting Ring
Lock Washer Head
O-Ring
Cam Follower
Body
Graduating Spring
Inlet Valve
Seat
Inlet Valve
Exhaust Port
Supply Port
Delivery Port
O-Ring
Cam
Gasket
Piston
O-Ring
Piston
Return Spring
Cover Stem
Spring
Exhaust Valve
TC-2™Brake
Valve Insert
O-Ring Spirol Pin
Handle
Knob
Head
Head Seal
O-Ring
FIGURE 3 - SECTIONAL VIEW
ASSEMBLY
Priortoassembly,lubricate the body and cover bores, cam
and cam follower, piston o-ring, and cover top with Dow
Corning 55-M pneumatic grease (Bendix piece number
291126).
1. Pressinletvalveonstem.Alittlewaterinthebootvalve
or some soap on the stem will make it easier to press
on the inlet valve.
2. PIace stem with inlet valve installed in inlet seat. Insert
someobjectsuch as a cap screw to holdtheinlet valve
up against its seat.
3. Position spring and exhaust valve guide.
4. Depress guide and spring, then press exhaust valve
on stem.
5. Place seal o-ring over insert seat and with cap screws
andlock washers installinletand exhaust insertinbody.
Recommended torque on insert cap screws is 60 to 80
inch pounds.
6. Install piston return spring.
7. Install piston o-ring on piston and install piston in
body.
8. Install adjusting ring in cover and screw it down until it
is flush with top of cover.
9. Place cam follower and cam in cover.
10.Position graduating spring and gasket in body.
11. Connect body to cover; tighten cap screws evenly and
torque to 75-95 inch pounds.
12.Install adjusting ring lock washer, head seal o-ring, and
head.
13.Install set screw in head of remote-operated type
valves. At this stage, before installing handle and
spirol pin of handle-operated type valve, if facilities
are available the rebuilt valve should be tested and
adjusted. If facilities are not available, the valve can
be tested on the vehicle.
TESTING REBUILT TC-2™BRAKE VALVE
Perform “Operating and Leakage Tests” as outlined in
“Service Checks” section.
ADJUSTMENT
Generally, the TC-2™brake valve should deliver full
reservoir pressure; however, there are a few exceptions
in special applications.
1. Ifthedeliveredpressure is belowspecifiedfinaldelivery
pressure, it can be adjusted by removing the head and
adjusting ring lock washer and rotating the adjusting
ring clockwise to raise the delivery pressure.
2. Ifthe delivery pressure is above specified finaldelivery
pressure, it can be lowered by rotating the adjusting
ring counterclockwise.

4BW1430 © 2007 Bendix Commercial Vehicle Systems LLC. All rights reserved. 6/2007 Printed in U.S.A.
Aspanner wrench can be used to rotate the adjusting ring,
but if such a wrench is not available, the adjusting ring
can be turned with a small screwdriver inserted in one of
the inner notches of the ring. Turning the adjusting ring
one notch will raise the delivered pressure approximately
5 psi.
WARNING! PLEASE READ AND FOLLOW
THESEINSTRUCTIONSTOAVOIDPERSONAL
INJURY OR DEATH:
When working on or around a vehicle, the following
general precautions should be observed at all times.
1. Park the vehicle on a level surface, apply the
parking brakes, and always block the wheels.
Always wear safety glasses.
2. Stop the engine and remove ignition key when
working under or around the vehicle. When
working in the engine compartment, the engine
should be shut off and the ignition key should be
removed. Where circumstances require that the
engine bein operation, EXTREMECAUTION should
be used to prevent personal injury resulting from
contact with moving, rotating, leaking, heated or
electrically charged components.
3. Do not attempt to install, remove, disassemble
or assemble a component until you have read
and thoroughly understand the recommended
procedures. Use onlythe proper toolsand observe
all precautions pertaining to use of those tools.
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 dryersystem ora dryerreservoir module,
be sure to drain the purge reservoir.
5. Followingthevehiclemanufacturer’srecommended
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®replacement parts,
components and kits. Replacement hardware,
tubing, hose, fittings, etc. must be of equivalent
size, type and strength as original equipment and
be designed specifically 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 specifically 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 beON) prior toperforming any vehicle
maintenance where one or more wheels on a drive
axle are lifted off the ground and moving.