BENDIX TC-6 BRAKE VALVE User manual

1
®
Bendix®TC-6™Trailer Control Brake Valve
SD-03-821
FIGURE 1
DESCRIPTION
The Bendix®TC-6™trailer control brake valve is normally
usedtooperatethetrailerbrakesindependentlyofthetractor
brakes.Itmaybeused,however,whereverahandcontrolled
pressuregraduation functionis desired.
TheTC-6™valveishandleoperatedandisdesignedforpanel
ordog housemounting.
TheTC-6™trailercontrol brake valveisnot designedforuse
as a parking brake control and should never be used to
holdthebrakesappliedwhentheoperatorleavesthevehicle.
OPERATION
APPLYING
Whenthe handle (item 10) ispulled through its75° arc,the
roller cam (item 11) is rotated accordingly. The cam action
forces the cam follower (item 9) downward, compressing
the graduating spring (item 6) and creating a force on the
plunger (item 12) which depresses the inlet valve (item 2)
and delivers air under pressure to the delivery port.
HOLDING
Asdelivery pressure builds upin the delivery port,it is also
effective under the plunger (12) causing it to balance the
force of the graduating spring (6) until the inlet valve (2) is
seatedagainstitsseatinthebody andisalsoseatedagainst
the plunger (12), thus preventing the delivery air from
exhausting through the center of the plunger (12),
maintaining the desired pressure in the delivery line.
RELEASING
Whenthehandleisreleasedormovedtoitsreleaseposition,
thecamfollower(9)is permittedtorise,openingthe exhaust
passageand allowingthe airpressure inthe deliveryline to
exhaustout theexhaustport.
PREVENTIVE MAINTENANCE
Important: Review the Bendix Warranty Policy before
performinganyintrusivemaintenanceprocedures.Awarranty
maybe voidedifintrusive maintenanceis performedduring
thewarranty period.
FIGURE 2
EXHAUST
DELIVERY
SUPPLY
KNOB
13
11
14
8
10
9
7
6
12
515 4
2
3
1
16

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No two vehicles operate under identical conditions, as a
result, maintenance intervals may vary. Experience is a
valuableguidein determiningthebestmaintenance interval
forair brakesystem components.At aminimum, theTC-6™
valveshouldbeinspectedevery6 months or1500operating
hours,whichever comes first, for proper operation. Should
the TC-6™valve not meet the elements of the operational
testsnotedinthisdocument,furtherinvestigationandservice
ofthevalve maybe required.
Every900 hours,25,000milesorevery3months,dropsome
lubricant such as BW-650M silicone lubricant (Bendix part
number 291126) (Dow Corning 55-M) through the handle
operating slot, to re-lubricate the cam roller and hinge pin.
Performoperating andleakage tests.
REMOVING AND INSTALLING
Secure vehicle with spring brakes or blocks. Drain the
reservoir which supplies the TC-6™valve. Remove the
fasteners which secure the mounting bracket to the panel.
Disconnectthe connectingair lines.Removevalve.
INSTALLING
Atypicalpipingarrangement fortheTC-6™valveisshown in
Fig. 3. Check connecting air lines for integrity and foreign
material. Replace lines if necessary. Re-connect air lines.
Replace fasteners securing bracket to panel. Check
operation of valve by charging system and performing the
service check as described in this manual.
SERVICE CHECKS
OPERATING
Connect an accurate test gauge to the trailer service line
hose and leave the trailer emergency or supply hose
connectedtothe trailerorif a trailerisnot available,connect
the trailer supply hose to an unvented dummy coupling or
toa pluggedhose fitting. Thetrailer supplyvalve shouldbe
in the normal position.
When the operating lever is moved to the fully applied
position, the gauge should register full reservoir pressure.
Intermediate positions should deliver proportional
intermediate pressures. Upon release, the gauge should
immediatelyregister zero.
The location of the atmospheric end of the exhaust line
from the valve should be found, probably in the engine
compartment.
With the TC-6™valve in the release position, no pressure
shouldregister onthe test gaugeand leakageat the end of
the exhaust line should not be greater than 100 SCCM
(1" bubble in 5 seconds).
With the valve fully applied, leakage at the exhaust line
should not be greater than 175 SCCM (1" bubble in 3
seconds).
Ifthe valvedoes notfunctionas described,or ifthe leakage
is excessive, it is recommended that it be returned to the
nearest Bendix authorized distributor for a factory
remanufacturedvalveunder theexchangeplan.If thisisnot
possible,thevalvecanberepairedwithgenuineBendixparts,
in which case the following should be helpful. The
maintenancekitfor theTC-6™valveis partnumber289890.
DISASSEMBLY
Remove the valve from the panel. Place the lever in a vise
and with a firm pull the rubber handle may be removed.
Remove the two slotted head cap screws (14) which hold
themountingbracketinplaceasshownin Fig. 2andremove
themounting bracket.
Drive the pivot pin (13) out of the body with a drift punch.
Thehandle (10), roller cam(11)andtorsion spring (8) may
nowbe removed. Removethe roller camfrom the handle.
The cam follower (9), graduating spring (6), plunger (12),
andplunger returnspring (4) maynow beremoved through
thetopofthevalve. Careshouldbetakennot tolosewasher
(15).
Placethebodyina soft-jawedviseandremovecapnut (16).
Removeo-ring(1) fromcap nut.
Inletvalvespring(3)andinletvalve(2)maynowberemoved.
CLEANINGAND INSPECTION OF PARTS
Clean all metal and plastic parts with mineral spirits or
equivalent. Wipe all o-rings and rubber parts dry. Replace
any which show signs of wear or deterioration. Inspect
valve seats for nicks or burrs and remove any deposits.
Check all springs for distortion, cracks and corrosion.
Replaceallpartsnotconsideredserviceableafterinspection.
ASSEMBLY
Before assembling the valve all bores, cam, pivot pin,
plungers, and o-rings should be lubricated with silicone
lubricantDow Corning55-M (Bendix partnumber 291126).
Placebodyin asoft-jawedvise withportspointing up.Place
inletvalve (2)in inletcavity andinstall inlet valve spring (3).
Place o-ring (1) on cap nut (16) and assemble cap nut in
body. Torque cap nut to 50-150 inch pounds.
Install o-rings (5) and (7) on plunger (12) and cam follower
(9).Caution:o-ring (7)is slightlylargerthan (5)and goes on
thecam follower(9).
Reverse position of body in vise and install plunger return
spring (4), plunger (12), washer (15), graduating spring
(6), and cam follower (9). Note: The cam follower must be
positioned so that the projection on the side of the body
matches the corresponding groove in the body.

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FIGURE 3
TC-6™VALVE
DOUBLECHECKVALVE SERVICELINE
REARBRAKE
RESERVOIR
SUPPLYRESERVOIR FRONT BRAKE
RESERVOIR
DOUBLE
CHECK
VALVE
TOREARBRAKES
TP-3™
VALVE
Positionthe torsion spring(8) in its approximate positionin
the body so that the end which engages the handle rests
against the side of the body opposite the bracket retaining
screwholes. Place theroller cam (11) inposition as shown
in Fig. 2 and insert pivot pin (13) through the torsion spring
and partially through the roller cam, leaving room to insert
thewedge shapedend ofthe handle.
Withasmall screwdriveror similartool,force thetangof the
torsion spring towards the opposite wall of the body far
enough so the handle (10) may be inserted into the roller
cam. The pivot pin (13) may then be tapped on through
until the ends of the pin are flush with either side of the
body.
Placethe mountingbracket in position and securewith two
slotted head cap screws (14).
Place the rubber knob back on the handle. Reinstall the
valveonthevehicle andtestper“operatingleakage checks”
in this manual.
WARNING! PLEASE READ AND FOLLOW
THESE INSTRUCTIONS TO AVOID
PERSONAL INJURYOR 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
enginebe in operation, EXTREMECAUTIONshould
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. Useonly the propertools and observe
all precautions pertaining to use of those tools.
TO FRONT
BRAKES

4BW1567 © 2004 Bendix Commercial Vehicle Systems LLC. All rights reserved. 3/2004 Printed in U.S.A.
4. If the work is being performed on the vehicle’s air
brake system, or any auxiliary pressurized air
systems,makecertaintodraintheair 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
recommendedprocedures,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
certainallcomponentsandsystemsarerestoredto
their proper operating condition.