BENDIX TR-2-TR-3-TR-4 INVERSION VALVE User manual

1
®
SD-03-4650
Bendix®TR-2™, TR-3™& TR-4™Inversion Valves
DESCRIPTION
GENERAL
TheTR-2™&TR-3™valvesarenormallyopenpilot-operated,
inverting, on-off, two-way valves. The TR-4™valve is lever
operated. With normal operating pressure at both supply
and control ports, the delivery port will be exhausted to
atmosphere. As control pressure is reduced to the point
thatthe pistonreturn springor springsovercomes theforce
onthecontrolpiston,thevalvewilldeliverfullsupplypressure
atthe delivery port.
TR-2™INVERSIONVALVE
ReferringtoFigure 1,the TR-2™valvewasused primarilyin
early DD-3™Safety Actuator control systems to apply air
pressure to the emergency diaphragm of the DD-3™
actuator’sfrom a protectedreservoir as controlpressure is
released from the lock mechanism. The TR-2™valve is
availablein 11/4" bulk head mountonly.
TR-3™INVERSIONVALVE
ReferringtoFigure2,the TR-3™valveissimilarinfunction to
theTR-2™valve,butwithadiecastbody. ReferringtoFigure
3,someTR-3™valve’s haveaninternalpassage inthebody
connectingsupply pressureto control.The externalcontrol
portis permanentlyplugged in suchvalves.
TR-4™INVERSIONVALVE
Referringto Figure4, theTR-4™valveis aTR-3™valve with
the internal passage connecting supply and control plus a
manuallevercontrol whichpermits thevalve tobelocked in
theopen position.
OPERATION
TR-2™& TR-3™INVERSION VALVES
Whensufficient air pressureis present in thecontrol cavity
toovercomethesettingofthe pistonreturnspring,thepiston
isheld awayfrom theinlet valvewhich isheld closedby the
inlet valve return spring. The delivery lines are vented to
atmospherethrough thehollow exhaust stemof thepiston.
When air pressure in the control cavity falls to a
FIGURE1-TR-2™INVERSIONVALVE
CONTROL PORT (3)
CAPSCREW
DELIVERYPORT(2)
CAP NUT
SEALRING
PISTON
MOUNTING NUT
&LOCKWASHER
INLET & EXHAUST
VALVE
PISTON GROMMET
(SMALL)
PISTON GROMMET
(LARGE)
EXHAUST
DIAPHRAGM
COVERPLATE
DIAPHRAGMWASHER
RETAINERRING
PISTON SPRINGS
BODY
INLET & EXHAUST
VALVESPRING
SUPPLY PORT
EXHAUST

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FIGURE2-TR-3™INVERSIONVALVE FIGURE 3 - TR-3™INVERSION VALVE
INTERNAL BLEED CONTROL
predeterminedpressureor isvented fromthecontrol cavity,
the piston spring forces the piston against the inlet valve
closing the exhaust passage in the hollow piston stem.
Furthertravelof thepistonopensthe inletvalveallowing the
passageof airpast theopen inletvalve andout thedelivery
port.
TheTR-3™valve withtheinternal controlpassage functions
thesameasaboveexceptthatthecontrolpressureisalways
thesame as thesupply pressure. Consequently,as supply
pressure builds up, when the pressure is great enough to
overcomethepiston returnspring,the deliverypressurewill
be vented out the exhaust. On descending supply/control
pressure,as thepiston returnspring overcomesthe control
pressurethevalvewilldeliverthe remainingsupplypressure
atthe delivery port.
TR-4™INVERSIONVALVE
TheTR-4™valveprovidesthe samefunctionsastheinternal
passaged TR-3™valve except the lever override gives the
operatortheoptionoflockingthevalveintheopenordelivery
position.
MOUNTINGLOCATION
Careshould begiven to assureproper mountinglocation of
thevalvewiththe exhaustpointeddownward,mounted high
on the frame rail, and away from road spray and debris.
Unprotectedor exposed exhaustports canallow migration
of road contaminants into the valve, which may cause
acceleratedwearor unintendedoperation.
PREVENTIVE MAINTENANCE
Important: Review the Bendix Warranty Policy before
performinganyintrusivemaintenanceprocedures.Awarranty
maybe voidedifintrusive maintenanceis performedduring
thewarranty period.
No two vehicles operate under identical conditions, as a
result, maintenance intervals may vary. Experience is a
valuableguidein determiningthebest maintenanceinterval
for air brake system components. At a minimum, the
inversionvalvesshouldbeinspectedevery6monthsor1500
operatinghours,whichevercomesfirst,forproperoperation.
Should the inversion valves not meet the elements of the
operationaltestsnotedinthisdocument,furtherinvestigation
andservice ofthevalve maybe required.
OPERATING AND LEAKAGE TESTS
NOTE: The following checks should be made with two
calibrated gauges or two gauges known to be
accurate. Depending upon installation, it may be
easierornecessaryto completelyremovethevalve
to test properly.
Installone test gaugein acommon control andsupply line;
install the other gauge in the delivery port. Gradually apply
pressure to the common supply and control line. On
ascendingpressure, noteat what pressureexhaust occurs
andcomparewithvehicle manual.Withairpressurepresent
insupply andcontrol port,apply asoap solution around the
supply port cap nut. No leakage is permitted. Apply soap
solutionto the deliveryand exhaust ports.Leakage should
not exceed 100 SCCM or a 1" bubble in not less than 5
seconds. Excessive leakage would indicate a faulty o-ring
orinletvalve.Operate themanualcontrolofthe TR-4™valve
andnote that deliveryand exhaust occur promptly.
INTERNAL
PASSAGE
EXHAUST DIAPHRAGM
1/4” P.T.
DELIVERY
EXHAUST
NUT
O-RING
O-RING
VALVE
SPRING
O-RING
INLET &
EXHAUST
VALVE
PISTON
DIAPHRAGM
RETAINER
CAP
1/8” P.T.
CONTROL
VALVESTOP
SHIM
PISTON SPRING
1/4”P.T.SUPPLY
PIPE
PLUG

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Slowly decrease pressure in the control cavity and note at
what pressure delivery is made and compare with vehicle
manual.
NOTE: In theTR-3™valveshown inFigure3andtheTR-4™
valve in Figure 4, control pressure is reduced by
decreasing supply air pressure because of the
internalpassage connecting supplyand control.
IftheTR-2™,TR-3™orTR-4™inversionvalvedoesnotfunction
as described or leakage is excessive, it is recommended
thatit bereplaced witha newvalve or remanufacturedunit,
or repaired with genuine Bendix parts available at Bendix
outlets.
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, 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 only the proper tools and 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,makecertain to drain the airpressurefrom
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
systemina manner that safely removes allelectrical
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.
FIGURE4-TR-4™INVERSIONVALVE
COVER
LEVER
1/4” P.T.
DELIVERY
LOCK NUT
O-RING
VALVE
SPRING
O-RING
INLET/EXHAUST
VALVE
PLUNGER
PIN
PLUGGED
VALVESTOP
SHIM
PLUNGER SPRING
1/4”P.T.SUPPLY
COVER NUT
CAP
PISTON SPRING
PISTON
O-RING

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REMOVALAND INSTALLATION
REMOVAL
Blockandholdvehiclebymeansotherthanair brakes.Drain
service and emergency or parking reservoirs. Disconnect
airlinesfromvalve.Removethemountingbolts,removevalve.
INSTALLATION
Remountvalvesecurelyusingholesprovidedinbody.Check
and clean air lines and reconnect.
DISASSEMBLY
NOTE: Care should be taken if body is clamped in vise.
Excessivetightening can cause distortion of valve
body.
TR-2™INVERSIONVALVE
1. Removethecapnutwithsealingring,removesealingring
fromcap nut.
2. Removethe inlet/exhaustvalve springand inlet/exhaust
valve.
3. Turnthe valve overand remove theexhaust diaphragm
cap screw with lockwasher, then the diaphragm washer
anddiaphragm.
4. With a pair of #1 Truarc pliers, remove the retainer ring.
Removethe coverplate and two(2) pistonsprings.
5. Removethe pistonwith grommets.
6. Removethe pistongrommets.
TR-3™INVERSIONVALVE
1. Removethe exhaust portcap nutand o-ring.
2. Removethe diaphragmretainerand pistonspring.
3. Removethe shimwasher orwashers (ifpresent).
4. Removethepiston fromthe valvebody.
5. Removethe pistono-ring and exhauststem o-ring.
6. Removethe supplycap nut ando-ring.
7. Removethevalve stopandspring.
8. Removetheinlet andexhaust valve.
TR-4™INVERSIONVALVE
1. Presslever pinout ofthelever andremove lever.
2. Removetheplungerandplungerreturnspringfromcover.
3. Removethe covernut lock nut.
4. Removethe covernutand o-ring.
5. Removethe coverand shimwasher orwashers.
6. Removethe pistonspring and pistonfrom body.
7. Remove the pistonand exhaust stemo-rings.
8. Remove the supplyport capnut and o-ring.
9. Removethe valve stopandvalvereturn spring.
10. Removethe inletand exhaustvalve.
CLEANING AND INSPECTION
Wash all metal parts in a good cleaning solvent. Rubber
partsshould be wipedclean.
Inspect all parts for signs of wear or deterioration. Check
the springs for cracks, corrosion, or distortion. Inspect the
piston and its exhaust seat, body bores, and inlet valve for
nicks, scratches, or burrs.
Replace all parts not considered serviceable during
inspection.
BW1581 © 2004 Bendix Commercial Vehicle Systems LLC. All rights reserved. 4/2004 Printed in U.S.A.
ASSEMBLY
Beforeassemblingthevalve,lubricatethepistono-rings and
bodybores withBendix siliconelubricant suchasBW650M
Bendix Pc. No. 291126.
TR-2™INVERSIONVALVE
1. Install the piston grommets on piston.
2. Install thepiston with grommetsin valve body.
3. Positionthe piston springs,cover plateand retainer ring
in the piston in that order. Press the cover and retainer
down and with a pair of Truarc #1 pliers, snap the ring
intothe bodygroove.
4. Installthediaphragm anddiaphragm washerandsecure
with cap screw.
5. Turn the inversion valve over and position the inlet and
exhaustvalve inits bore.
6. Placethe springoverinlet valve.
7. Installthe sealingring oncap nut.Install thecap nut with
sealing ring and tighten securely. Torque to approx. 125
in. lbs.
8. Usingthe mountingnut andlockwasher,install thevalve
onvehicle.
TR-3™INVERSIONVALVE
1. Install the inlet and exhaust valve in the body (supply
port).
2. Installtheinletvalve springandvalvestop(centerstop on
spring).
3. Install the o-ring on the supply cap nut and install and
tighten the cap nut. Torque to approx. 100 in. lbs.
4. Installthepistonandexhauststem o-ringon piston.Install
the piston in body.
5. Installtheshim washerorwashers (ifpresent). Install the
pistonspring.
6. Installthe diaphragmretainer andexhaust diaphragm.
7. Installtheo-ringonexhaustcapnutand installand tighten
the cap nut. Torque to approx. 275 in. lbs.
TR-4™INVERSIONVALVE
1. Replacethe inletand exhaustvalve.
2. Installthe valvereturnspring andvalve stop.
3. Installtheo-ringonsupplycap nutandinstall andtighten
the cap nut. Torque to approx. 100 in. lbs.
4. Installthe pistonandexhaust stemo-ring onthe piston.
Install the piston in the body.
5. Install the piston spring.
6. Installthe coverand washer orwashers.
7. Replacethe covernuto-ringon thecovernut andinstall
andtighten thecover nut.Torqueto approx.275 in.lbs.
8. Installthe plungerreturn springand plunger.
9. Install the cover nut lock nut. Torque to approx. 100 in.
lbs.
10. Installlever and pressthe lever pinin to secure.
TESTINGREBUILT VALVES
Performoperatingandleakagetestsasoutlinedin“Operating
and Leakage Tests” section.