BENDIX E-7 DUAL BRAKE VALVE User manual

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®
SD-03-818
Bendix®E-7™Dual Brake Valve
valvecloses,thesecondaryinletvalveismovedoffitsseat
allowingsecondaryairpressureto flowoutthe deliveryport.
Because of the small volume of air required to move the
relay piston, action of the secondary circuit portion of the
valve is almost simultaneous with the primary circuit
portion.
APPLYING: LOSS OF AIR IN SECONDARY
CIRCUIT
Should air be lost in the secondary circuit, the primary
circuit portion will continue to function as described above
under NormalOperation:Primary Circuit Portion.
DESCRIPTION
The Bendix®E-7™dual brake valve is a suspended,
pedal-operated type brake valve with two separate supply
and delivery circuits for service and emergency braking,
whichprovides the driverwitha graduatedcontrolfor apply-
ingand releasing the vehicle brakes.
The circuits in the E-7™dual brake valve are identified as
follows:The primarycircuitportionisthat portionofthevalve
betweenthespring seatwhichcontactsthe plungerandthe
relay piston; the secondary circuit portion is that portion
between the relay piston and the exhaust cavity.
Theprimary circuitportionofthe valveissimilar inoperation
to a standard single-circuit air brake valve, and under nor-
mal operating conditions the secondary circuit portion is
similar in operation to a relay valve.
Theprimary circuitportionofthevalve ispartof aremovable
cagewhich alsohousestherelay pistonandthe cagewhich
canbe removed withoutremovingthe entirebrakevalve.
Both primary and secondary circuit portions of the E-7™
dual brake valve use a common exhaust protected by an
exhaustcheckvalve.
OPERATION
APPLYING: NORMAL OPERATION - PRIMARY
CIRCUIT PORTION
Whenthebrakepedal isdepressed, theplungerexertsforce
on the spring seat, rubber graduating spring, and primary
piston.The primarypistonwhichcontains theexhaustvalve
seat,closes theprimaryexhaustvalve.Astheexhaustvalve
closes,theprimaryinletvalveismovedoffitsseatallowing
primary air pressure to flow out the delivery port.
APPLYING: NORMAL OPERATION -
SECONDARY CIRCUIT PORTION
When the primary inlet valve is moved off its seat, air is
permittedto passthroughthebleed passageandenters the
relay cavity. The air pressure moves the relay piston, and
the relay piston, which contains the exhaust seat, closes
the secondary exhaust valve. As the secondary exhaust
SECONDARY
DELIVERY
PRIMARY
DELIVERY
PRIMARY
SUPPLY
SECONDARY
SUPPLY
MOUNTING
PLATE
FIGURE 1 - E-7™DUAL BRAKE VALVE

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APPLYING: LOSS OF AIR IN PRIMARY CIRCUIT
Should air be lost in the primary circuit, the function will be
as follows: As the brake pedal is depressed and no air
pressureis presentinthe primarycircuitsupply anddelivery
ports, the primary piston will mechanically move the relay
piston allowing the piston to close the secondary exhaust
valveandopenthesecondaryinletvalveandallowairpressure
to flow out the delivery port.
BALANCED: PRIMARY CIRCUIT PORTION
When air pressure delivered to the brake actuators and air
pressure in the cavity on the delivery side of the primary
pistonequalsthe mechanicalforceof the brakepedalappli-
cation, the primary piston will move and the primary inlet
valve will close, stopping the further flow of air from the pri-
marysupplylinethroughthevalve.Theexhaustvalveremains
closed preventing any escape of air through the exhaust
port.
BALANCED: SECONDARY CIRCUIT PORTION
When the air pressure on the secondary side of the relay
piston approaches that being delivered on the primary side
of the relay piston, the relay piston moves closing the sec-
ondary inlet valve and stopping further flow of air pressure
fromthe supplylinethrough thevalve.Theexhaustremains
closed as the pressures balance.
Whenapplicationsin the graduatingrangeare made, abal-
anced position in the primary portion is reached as the air
pressure on the delivery side of the primary piston equals
the effort exerted by the driver’s foot on the pedal. A bal-
ancedpositionin thesecondaryportionis reachedwhenair
pressure on the secondary side of the relay piston closely
approachestheair pressureontheprimary sideoftherelay
piston.
When the brake pedal is fully depressed, both primary and
secondary inlet valves remain open and full reservoir pres-
sure is delivered out the delivery ports.
RELEASING: PRIMARY CIRCUIT PORTION
Withthe brakepedalreleased,mechanicalforce isremoved
fromthespring seat, rubber graduatingspring,andprimary
piston.Airpressure and spring load moves the primary pis-
ton,opening theprimaryexhaustvalveallowing airpressure
in the primary delivery line to exhaust out the exhaust port.
RELEASING: SECONDARY CIRCUIT PORTION
With the brake pedal released, air is exhausted from the
primary side of the relay piston. Air pressure and spring
loadmovethe relay piston, openingthesecondaryexhaust
valveallowingairpressureinthesecondarydeliverylineto
exhaust out the exhaust port.
PREVENTIVE MAINTENANCE
Important: Review the Bendix Warranty Policy before
performinganyintrusivemaintenanceprocedures.Awarranty
maybevoided if intrusivemaintenanceisperformed during
thewarrantyperiod.
No two vehicles operate under identical conditions, as a
result,maintenanceintervalsmayvary. Experienceis avalu-
able guide in determining the best maintenance interval for
airbrake systemcomponents.Ataminimum,the E-7™valve
shouldbeinspectedevery6monthsor1500operatinghours,
whichever comes first, for proper operation. Should the
E-7™valve not meet the elements of the operational tests
noted in this document, further investigation and service of
thevalve may berequired.
Every 3 months, 25,000 miles, or 900 operating hours:
Lubricate fulcrum and roller pin with Barium grease per
BW-204-M(Bendixpart 246671).
Free pedal travel should be checked as follows: Check to
be certain plunger is in contact with spring seat. The stop
buttonshouldbe adjusted so thattherollerand plunger just
contact.
Applyathin layer ofBariumgrease, per BW-204-M(Bendix
part246671), betweenplungerand mountingplate– do not
over oil!
Clean exhaust check depending on type of service.
SERVICE CHECKS
OPERATING
Checkthedelivery pressure ofbothprimaryand secondary
circuits using test gauges known to be accurate. Depress
the pedal to several positions between the fully released
and fully applied positions, and check the delivered pres-
sure on the test gauges to see that it varies proportionately
with the movement of the brake pedal.
When the treadle is fully applied, the reading on the test
gauge should fall off to zero promptly when the application
isreleased.Itshouldbenotedthattheprimarycircuitdeliv-
erypressurewillbeabout2psigreaterthansecondarycircuit
deliverypressurewith primary andsecondarycircuit supply
reservoirsat thesamepressure.This isnormalin thisvalve.
IMPORTANT
Anincreaseinstopping distance or alowpressurewarning
indicatesamalfunction inoneorthe otherbrakecircuit,and
althoughthevehicle airbrakesystemmay continuetofunc-
tion,thevehicleshouldnotbeoperateduntilthe necessary
repairshavebeen made andbothbrakingcircuits are oper-
ating normally.

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FIGURE 2 - E-7™DUAL BRAKE VALVE
INLET-EXHAUST
ASSEMBLY (1) RETAINER (17)
O-RING (2)
O-RING (3)
RELAY SPRING (5)
O-RING (11)
O-RING (9)
O-RING (12)
RETAINER (18)
ROLLER
SEALING
RINGS
PLUNGER FULCRUM PIN
STOP BUTTON
PEDAL
*OPTIONAL MANIFOLD FOR INSTALLATIONS
REQUIRING SUPPLY & DELIVERY LINE
CONNECTIONS ON ENGINE SIDE OF ENGINE
COMPARTMENT BULKHEAD.
MANIFOLD*
SPRING SEAT (15)
STEM SPRING (23)
SPRING SEAT NUT (16)
LOCK NUT (14)
PISTON SPRING (8)
O-RING (6)
O-RING (7)
RETAINER (20)
EXHAUST CHECK
VALVE
SCREW (21)
WASHER (22)
DIAPHRAGM (13)
INLET-EXHAUST
ASSEMBLY (4)
RUBBER SPRING (10)
RUBBER SPRING SEAT (19)

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LEAKAGE CHECK
1. Make and hold full brake application.
2. Coat the exhaust port and body of the brake valve with
soap solution.
3. Leakagenot to exceed a 1” bubble in 3 seconds inboth
theapplied and released position.
If the brake valve does not function as described above or
leakageisexcessive,it is recommended thatitbereplaced
withagenuineBendix newor remanufacturedunit,available
at your local authorized Bendix parts outlet.
REMOVAL (IF NECESSARY)
1. Block the wheels or hold the vehicle by means other
thanair brakesandexhaust airpressurefrom reservoirs
supplying air to the E-7™valve.
2. In most installations, the E-7™internal parts may be
removedandreplacedbyremovingthethreecapscrews
which hold the pedal assembly in place and removing
the pedal assembly. The internal parts may then be
removed from the E-7™as described in disassembly.
3. If necessary to remove the E-7™from the engine
compartmentbulkhead,identifythetwo supply and two
delivery lines to their respective ports as connected to
the brake valve. There may also be air lines to other
brake devices inside the cab, which should be properly
identifiedbefore disconnecting.Inthe caseofamanifold
type installation, the three cap screws which hold the
manifold to the brake valve may be removed and the
brakevalveremoved.
DISASSEMBLY (REFER TO FIGURE 2)
1. Remove retainer, (18). Remove the lower static piston
assembly.
2. Fashion a hook from a piece of wire and insert hook
through inlet-exhaust valve of upper static piston
assembly. Pull firmly and remove upper static piston
assembly.
DISASSEMBLY (UPPER STATIC PISTON
ASSEMBLY)
1. Removeo-rings(2) and(3).
2. Removeretainingring(17),andremovesecondarycircuit
inlet exhaust assembly (1).
DISASSEMBLY OF LOWER STATIC ASSEMBLY
1. Apply firm pressure on spring seat (19), which will
compresspistonreturn spring. Lockinggrooveinpiston
is now accessible through rectangular opening in lower
staticpiston body.Insertwire or screwdriverintolocking
groove,thusholdingstaticpiston spring in compressed
position.
2. Insertbladeofscrewdriver through relaypistonexhaust
passage into slot of stem, and remove lock nut (14),
being careful not to nick the exhaust seat of the relay
piston.
3. Remove spring seat (15), stem spring (23), spring seat
nut(16),rubber springseat(19),and rubberspring,(10).
4. Relay piston, relay spring, (5) and stem bolt may now
beremoved.
5. Removalofscrewdriverorwirefromlockinggroovewill
permitspring loadtopushthe primarycircuitpiston from
thelower staticpiston.Note: Careshould beusedwhen
removingtoolfrom locking ring because of spring load.
6. Removeo-rings(6& 7) from relay piston ando-ring,(9)
from primary circuit piston.
7. Remove o-rings (11 & 12) from lower static piston.
8. Removelargeretainingring(20)fromlower staticpiston,
andremove primarycircuitinlet/exhaust valveassembly
(4).
DISASSEMBLY-EXHAUST CHECK VALVE
Some E-7™brake valves have an air exhaust check valve
(13, 21 & 22) as shown on Figure 2. If so, remove screw
(21),and washer(22),anddiscarddiaphragm (13).Replace
(21)and(22) using newdiaphragm(13).
ASSEMBLY
Note: Before assembly, lubricate all o-rings, bores, and
matingsurfaces withsiliconelubricant, pc.no.291126 (Dow
Corning 55-M). Do not lubricate rubber spring.
1. Install secondary circuit inlet-exhaust assembly (1) in
upper static piston, making certain retaining ring (17) is
engagedingrooveof upper static piston bore.
2. Installo-rings(2 & 3)onupperstatic piston andinstallin
valvebody.
3. Install primary circuit inlet-exhaust assembly in lower
staticpistonmakingcertainretainingring(20)isengaged
in groove of lower static piston bore.
4. Installthree o-rings(2of11),and(12)in groovesof lower
static piston assembly. (Note: The larger diameter
o-ring is installed in groove nearest to bottom of piston
assembly.)
5. Install o-rings (6) and (7) on relay piston and o-ring (9)
on primary circuit piston.
6. Carefully clamp primary circuit piston in a soft-jawed
vise taking care not to damage the exhaust seat or the
outsidediameter.Assembletherubberspring,(10) over
the center stem of the center of the piston, then the
spring seat (19) and the spring seat nut (16). Tighten
the spring seat nut until the end of the piston stem and
the spring seat nut are flush.

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7. Insert relay piston spring (5) and relay piston in top end
of lower static piston, and primary circuit piston spring
(8) and primary circuit piston assembly in the bottom of
lower static piston.
8. Installstemboltthroughbore ofrelay piston,invertentire
lower static piston assembly and position over a
screwdrivermountedinavise.Engagescrewdriverblade
in slot in head of stem.
9. Depress primary circuit piston assembly against spring
until locking groove is accessible through rectangular
holeinside of lowerstaticpiston.Engagea screwdriver
orwire inlockinggrooveandrelease pressureonpiston.
10. Install stemspring, (23),spring seat,(15) andstem nut,
(14). Torque to 20-30 inch Ibs.
11. Installlower static piston assemblyinvalvebody.Install
retainer, (18), making certain locking tabs engage boss
onvalvebody.
PEDAL ASSEMBLY
Installpedalassembly using threecapscrews.Check to be
certain plunger is in contact with spring seat. The stop but-
tonshould be adjustedsothat therollerand plungercontact
afteradjustment,roller should beableto be turnedfreelyby
thumb.
SERVICE CHECKS
OPERATING
Checkthedelivery pressure ofbothprimaryand secondary
circuits using accurate test gauges. Depress the pedal to
several positions between the fully released and fully ap-
plied positions, and check the delivered pressure on the
test gauges to see that it varies proportionately with the
movementofthe brake pedal.
When the treadle is fully applied, the reading on the test
gauge should fall off to zero promptly when the application
isreleased.Itshouldbenotedthat theprimarycircuitdelivery
pressure will be about 2 psi greater than secondary circuit
deliverypressurewith primary andsecondarycircuit supply
reservoirsat thesamepressure.This isnormalin thisvalve.
LEAKAGE
1. Make and hold full brake application.
2. Coat the exhaust port and body of the brake valve with
soap solution.
3. Leakagenot to exceed a 1” bubble in 3 seconds inboth
theapplied and released position.
If the brake valve does not function as described above or
leakageisexcessive,it is recommended thatitbereplaced
withagenuineBendix newor remanufacturedunit,available
at your local authorized Bendix parts outlet.
FIGURE 3 - TYPICAL PIPING SCHEMATIC
QUICK
RELEASE
VALVE
TP-5™TRACTOR
PROTECTION VALVE
MV-3™
MANIFOLD
VALVE
BRAKE
CHAMBER
SLACK
ADJUSTER
COMPRESSOR
SUPPLY
RESERVOIR #1 SERVICE
RESERVOIR #2 SERVICE
RESERVOIR
DOUBLE
CHECK
VALVE
SPRING
BRAKES
SLACK
ADJUSTER
DUAL BRAKE
VALVE
TRAILER
CONTROL
VALVE
BP-R1™
BOBTAIL
PROPORTIONING
VALVE
AIR DRYER

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GENERAL SAFETY GUIDELINES
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
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. Useonly the 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 certainto drainthe airpressure 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 theelectrical
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 be ON) prior to performing any vehicle
maintenance where one or more wheels on a drive
axle are lifted off the ground and moving.

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8BW1428 © 2006 Bendix Commercial Vehicle Systems LLC. All rights reserved. 7/2006 Printed in U.S.A.