BENDIX E-12-E-15 BRAKE VALVE User manual

1
®
SD-03-826
Bendix®E-12™& E-15™Dual Brake Valve
FIGURE 1 - E-12™AND E-15™DUAL BRAKE VALVES
The E-12™and E-15™valves are designed such that the
treadle does not sit in an upright position until the air sys-
temisbuiltuptofullreservoirpressure.Thesupplypressure
movestheprimarypistonupwardtransmittinga mechanical
force to the spring retainer and plunger of the treadle
assembly,causing thetreadle tomove upright.
TREADLE
MOUNTING
PLATE
PRIMARY
DELIVERY
DEL-1
21
()
SECONDARY
DELIVERY
DEL-2
22
()
PRIMARY
SUPPLY
SUP-1
11
()
PRIMARY
SUPPLY
SUP-2
12
()
()
SECONDARY
DELIVERY
DEL-2
22
PRIMARY
DELIVERY
DEL-1
21
()
UPPER
BODY
ASSEMBLY
DESCRIPTION
TheE-12™andE-15™dual brakevalvesare floormounted,
treadleoperatedtypebrakevalveswithtwoseparatesupply
anddeliverycircuitsforservice and secondarybraking.The
separation of circuits provides the driver with a graduated
controlfor applying andreleasing the vehiclebrakes.
TheE-12™andE-15™brakevalvesaresimilarindesignwith
theexceptionoftherubber spring (9)andspringretainer(7)
located in the upper body. The rubber spring which is used
intheE-12™brakevalvealters the performance ofthevalve
suchthat theprimary circuit delivers full reservoirpressure
to the spring brakes with less treadle travel than that of the
E-15™brakevalve.SeeFigure2fordeliverypressureversus
treadletraveldiagram.ThegreatertreadletraveloftheE-15™
brakevalve yields a more gradualdeliveryofairtothespring
brakesresultinginalesssensitive“feel”tothedriverwhena
brake application is made. This characteristic makes the
E-15™brakevalvemoreadaptabletotransitvehicleapplica-
tions where smooth brake applications contribute to
passengercomfort.
EXHAUST
LOWER
BODY
ASSEMBLY
E-12™DUAL
BRAKE VALVE
TREADLETRAVEL
PRIMARY DELIVERY
(PSI)
E-15™DUAL
BRAKE VALVE
TREADLETRAVEL
PRIMARY DELIVERY
(PSI)
↑↑
↑↑
↑
↑↑
↑↑
↑
FIGURE 2 - TREADLE TRAVEL VERSUS DELIVERY
PRESSURE

2
FIGURE 4 - TYPICAL PIPING SCHEMATIC
FIGURE 3 - E-12™DUAL BRAKE VALVE CROSS
SECTIONAL VIEW
26
30
31
32
10
14
25 24
15
LOWER BODY
18
19
UPPER BODY
5
7
6
8
9
15
13
10
17
12
13 14 11
1
2
3
4
4
21 23
22
20
28 27
29
The circuits in the E-12™/E-15™valves are identified as
follows: The no. 1 or primary circuit is that portion of the
valve between the primary piston (2) and the secondary
piston (18); the no. 2 or secondary circuit portion consists
of the area between the secondary piston and the exhaust
cavity.
Thesupply,delivery and exhaust portsof the E-12™/E-15™
brakevalvesareidentifiedbydesignationscastintothevalve
bodyadjacent totheir associatedport. (SeeFigure 1).The
primary supply and delivery ports are located in the upper
bodyportion while thesecondary supplyand delivery ports
arelocated in thelower bodyportion of thevalve.
The primary circuit of the valve is similar in operation to a
standard single-circuit air brake valve and under normal
operating conditions the secondary circuit is similar in
operationtoarelay valve.
Both the primary and secondary circuits of the brake valve
useacommon exhaust protected by an exhaust diaphragm.
OPERATION
APPLYING: NORMAL OPERATION-PRIMARY
CIRCUIT PORTION
Whenthe brake treadle(26) isdepressed, the plunger(27)
exerts a force on the spring retainer (7), graduation spring
(8) and primary piston (2). The primary piston, which con-
tains the exhaust valve seat closes the primary circuit
exhaustvalve.Astheexhaustvalveclosestheinletvalve for
theprimary circuit movesoffof itsseatallowing theairfrom
thesupply portof the primary circuit toflow outthe delivery
port of the same circuit.
QUICK
RELEASE
VALVE
TP-5™TRACTOR
PROTECTION
MV-3™
MODULE
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
1211

3
BALANCED: PRIMARY CIRCUIT PORTION
Whentheprimarydeliverypressureactingupontheprimary
piston(2), equals theresultantmechanicalforceofthebrake
treadleapplication, the primary piston willclose preventing
further air flow from the supply to the delivery port of the
brakevalve. Theexhaust valveremains closed preventing
the escape of air through the exhaust port.
APPLYING: NORMAL OPERATION-
SECONDARY CIRCUIT PORTION
The relay piston moves down with the primary piston and
closes the secondary circuit exhaust. When the inlet valve
in the primary portion of the valve is moved off its seat, air
passes through the bleed passage in the lower portion of
the upper body and enters the relay piston cavity. The air
moves the relay piston (18) downward and opens the sec-
ondaryinletvalve,allowingtheairfromthesecondarysupply
to flow out the delivery port of the same circuit.
APPLYING: LOSS OF AIR IN THE PRIMARY
CIRCUIT
If air is lost in the primary circuit, the valve will function as
follows: As the brake pedal is depressed and no air pres-
sure is present in the primary circuit, the primary piston (2)
willmechanicallymove the relaypiston closing thesecond-
ary exhaust and opening the inlet valve of the same circuit
allowing air flow from the secondary supply to its associ-
ateddeliveryport.
APPLYING: LOSS OF AIR IN THE SECONDARY
CIRCUIT
If the air is lost in the secondary circuit, the primary circuit
will function as described above under Normal Operation:
Primarycircuit portion.
FIGURE 7 - APPLYING - FAILURE IN THE SECONDARY
CIRCUIT
FIGURE 5 - APPLYING - NORMAL OPERATION FIGURE 6 - APPLYING - FAILURE IN THE PRIMARY
CIRCUIT
PLUNGER
FORCE 72
8
DEL-1
DEL-2
SUP-1
SUP-2
EXHAUST
PLUNGER
FORCE
DEL-2
SUP-1
SUP-2
EXHAUST
2
DEL-1
PLUNGER
FORCE 72
8
DEL-1
DEL-2
EXHAUST
SUP-1
SUP-2
18
18

4
FIGURE 8 - BALANCED POSITION
BALANCED: SECONDARY CIRCUIT PORTION
When the air pressure on the secondary side of the relay
pistonapproaches thepressure being delivered on thepri-
marysideofthe relay piston,therelaypistonmoves closing
thesecondaryinletvalvepreventingfurther air flow from the
supply line through the valve. The exhaust remains closed
as the secondary delivery pressure balances the primary
deliverypressure.
FIGURE 9 - RELEASED MODE
RELEASING: PRIMARY CIRCUIT PORTION
When the force on the brake treadle is released, the me-
chanicalforceis removed from the graduation spring (8)and
the primary piston (2). Air pressure in the delivery circuit
movestheprimarypistonexhaustivevalve, allowingairpres-
sure in the primary piston to exhaust through the exhaust
port.
RELEASING: SECONDARY CIRCUIT PORTION
When the brake treadle is released, air is exhausted from
theprimarycircuit sideofthe relay pistonthrough the bleed
passage.Airpressure in the delivery side of thesecondary
circuitmovesthe relaypistonupward, opening thesecond-
ary exhaust valve allowing air pressure in the secondary
delivery line to exhaust out the exhaust port.
PREVENTIVE MAINTENANCE
Important: Review the warranty policy before performing
any intrusive maintenance procedures. An extended war-
ranty may be voided if intrusive maintenance is performed
duringthis period.
Becausenotwovehiclesoperateunderidenticalconditions,
maintenance and maintenance intervals will vary. Experi-
enceisavaluableguideindeterminingthebestmaintenance
intervalforany one particularoperation.
Visuallycheck for physicaldamageto thebrakevalve such
as broken air lines and broken or missing parts.
EVERY 3 MONTHS, 25,000 MILES OR 900 OPERATING
HOURS:
1. Remove any accumulated contaminates such as dirt
andgravelfromtheheel of the treadle(26),plunger(27)
plungerboot(28) andmountingplate (29).
2. Use a light oil, lubricate the treadle roller (30), roller pin
(31)andhinge pin (32).
3. Inspect the plunger boot (28) for cracks, holes or dete-
riorationandreplace ifnecessary.Alsocheck mounting
plate and treadle for integrity, wear and corrosion and
replaceor repairasnecessary.
4. Apply2 to 4 drops ofoil betweenplunger and mounting
plate - do not over oil!
5. Check for excessive leakage as described in the
Operation & Leakage Checks section of this manual.
EVERY YEAR, 100,000 MILES, OR 3,600 OPERATING
HOURS:
1. Performsteps1 through4above.
2. Performtheoperation and leakagechecksdescribed in
theOperation&LeakageCheckssectionofthismanual.
PLUNGER
FORCE 2
DEL-2
SUP-1
SUP-2
EXHAUST
DEL-1
PLUNGER
FORCE 2
DEL-2
SUP-1
SUP-2
EXHAUST
DEL-1
8

5
OPERATION & LEAKAGE CHECKS
GENERAL
A change in vehicle braking characteristics or a low pres-
surewarningmay indicateamalfunction in oneor the other
brake circuit, and although the vehicle air brake system
may continue to function, the vehicle should not be oper-
ateduntil thenecessary repairshave been made and both
braking circuits, including the pneumatic and mechanical
devices are operating normally. If the brake valve does
not functionas described above or leakage is excessive,
itisrecommendedthatit be replaced withaneworremanu-
factured unit available at Bendix outlets.Always check the
vehiclebrake systemfor properoperation after performing
brakeworkand before returningthe vehicle toservice.
OPERATING CHECK
Checkthedelivery pressure ofbothNo. 1 andNo.2 circuits
using test gauges known to be accurate.
Note: Thetreadleorpedal will notbeina“normal” released
positionuntilthe air brakesystemis pressurized. Thepedal
ortreadlewillrise to its normalreleasepositionas the brake
system is pressurized from 0 psi.
Depress the treadle to several positions between the fully
releasedandfullyappliedpositionsand check the delivered
pressureonthe test gauges toseethat it variesequallyand
proportionatelywith the movementof the brakepedal.
After a full application is released, the reading on the test
gauges should fall off to zero promptly. It should be noted
that the No. 1 circuit delivery pressure will be about 4 psi
greater than the No. 2 circuit delivery pressure with both
supply reservoirs at the same pressure. This in normal for
thisvalve.
LEAKAGE CHECK
Make and hold a pressure application of 20 psi.
Coat the exhaust port and body of the brake valve with a
soapsolution.
Leakage permitted is a 1" bubble in 3 seconds in both the
appliedand released positions.
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
enginebeinoperation,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 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,make certain to drain theairpressure 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,deactivatethe 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 cer-
tain all components and systems are restored to
their proper operating condition.
VEHICLE PREPARATION
1. Parkthevehicleon a level surfaceandblockthe wheels
and/or hold the vehicle by means other than the air
brakes.
2. Draintheair pressure fromall vehicle reservoirs.
VALVE REMOVAL
1. Identify and mark or label all air lines and their respec-
tiveconnections onthe brake valve to facilitate ease of
installation. Disconnect all air lines.
2. Markthe relationship of the valve body to the mounting
plate then remove the valve from its mounting on the
vehicle.

6
FIGURE 10 - EXPLODED VIEW
7
(E-12) 23
21
22
16
24
25
LOWER BODY
14
15
13
12
11
10
19
18
20
7 (E-15)
6
1
8
9 (E-12)
3
4
5
14
15
4
2
13
12
11
10
UPPER
BODY
17

7
DISASSEMBLY
Thefollowing disassembly andassembly procedure ispre-
sentedforreferencepurposesandpresupposesthat amajor
rebuild of the brake valve is being undertaken. Several re-
placement parts and maintenance kits are available which
do not require full disassembly. The instructions provided
with these parts and kits should be followed in lieu of the
instructionspresented here.
Caution: The brake valve may be lightly clamped in a
bench vise during disassembly, however, over clamping
willresult in damageto thevalve and resultin leakage and/
or malfunction. If a vise is to be used, position the valve so
that the jaws bear on the delivery and supply ports on
opposingsides of thevalve’supper body.
1. Removeall air line fittings andplugs.
2. Mark the relationship of the upper and lower body (a
scribed line can be used) then remove the four cap
screws (16) that secure the lower body to the upper
body. Separate the two body halves and remove and
discardthe o-ring (17).
3. Pullthesecondarypiston(18) out of theupperbodyand
removeand discardthe o-rings(19 & 20) from it.
4. Remove and discard the special beveled retaining ring
(10) from the lower body while manually holding and
compressingthe valve seat(11)inplace.
5. Slowlyrelease the valveseat (11), allowingit to riseout
ofthebody. Removethevalveseat(11)thenremoveand
discardthe o-ring (12).
6. Removeanddiscardthevalve assembly (13) alongwith
its o-ring (15) from the lower body. Remove the valve
assemblyreturn spring (14).
7. Carefully remove and discard the exhaust diaphragm
retainer(24)andexhaustdiaphragm(25)fromthelower
body.
Note:SomeE-12™&E-15™brakevalveshavethreaded
exhaust ports in lieu items 24 & 25.
8. Usingfingerforce, push thepiston(2)into the bodyuntil
the piston retaining ring (1) is fully visible. Remove the
piston retaining ring (1), taking care not to damage the
piston bore in the body.
9. Gently tap the body on a soft surface to remove the
piston (2). Remove and discard the o-rings (3 & 5) and
bothwear rings(4) fromthe piston(2).
10. Place thepiston ona flatsurface andusing fingerforce,
depress and hold the spring retainer (7), then remove
anddiscard theretaining ring(6) fromthe piston(2).
11. Gently releasethe spring retainer (7), allowingit to rise
out of the piston. Remove the spring retainer (7) and
graduatingspring (8) fromthe piston (2).
12. Remove and discard the rubber spring (9) from the
interiorof thepiston (2).
Note: The rubber spring (9) is installed in the E-12™
brakevalveonly.
13. Remove and discard the special beveled retaining ring
(10) from the piston (2) while manually holding and
compressingthe valve seat(11)inplace.
14. Slowly releasethe valveseat (11),allowing itto riseout
of the piston (2). Remove the valve seat (11), then
removeanddiscard the o-ring(12).
15. Removeanddiscardthevalveassembly (13) alongwith
its o-ring (15) from the piston (2). Remove the valve
assemblyreturn spring (14).
CLEANING & INSPECTION
1. Usingmineralspiritsor an equivalent solvent,cleanand
thoroughly dry all metal parts.
2. Inspect the interior and exterior of all metal parts that
will be reused for severe corrosion, pitting and cracks.
Superficial corrosion and or pitting on the exterior por-
tionof theupper andlower body halves is acceptable.
3. Inspectthe bores of both body halves for deep scuffing
orgouges.
4. If the primary piston (2) is to be reused make certain
that vents “A & B” are open and free of obstructions.
5. Make certain vent “C” is open in the upper body of the
valve.
6. Inspect the pipe threads in both body halves. Make
certainthey areclean andfree ofthread sealant.
7. Inspectthetreadleorpedalassemblyandmountingplate
which attaches to the basic valve. Make certain that
the treadle or pedal roller turns freely and is lightly
lubricated.
Note: Sometreadle/pedalassemblies, not furnishedby
Bendix, do not employ a roller in which case make cer-
tain the mechanism in use moves across the plunger
smoothlywithoutbindingorsticking.Inspecttheplunger
forexcessivescuffingand wear.Checktheplungerbore
inthemountingplatefor excessive wearasexhibitedby
“egg shaping.” Inspect the mounting plate for severe
corrosionpaying particular attentionto thearea around
thepedal or treadle fulcrum pinbores.
8. Whenapplicable(inuse),check therubberbootinstalled
between the plunger and mounting plate for deteriora-
tion or cracking. Replace if necessary.
9. Inspectall air linefittings and plugsfor corrosion. Clean
allold threadsealant fromthe pipe threads.
Anyvalveor treadle assemblycomponentexhibiting acon-
ditiondescribedininspectionsteps1to9shouldbediscarded
andreplacedbeforeproceeding.

8
ASSEMBLY
1. Using the lubricant provided (Bendix Pc. No. 291126),
lightlycoat all o-rings,o-ring bores andgrooves. Lightly
lubricatetheprimarypiston(2)boreintowhichthegradu-
ating spring (8) is installed.
2. Placethe primarypiston (2) on a flat surface andinstall
therubber spring (9)and metal graduatingspring (8).
Note: The rubber spring (9) is used in the E-12™brake
valveonly.Ifa rubberspring wasnot removed in disas-
sembly step 11, discard this component - do not
install it.
3. Installthepropergraduating spring retainer(7)ontopof
the graduating spring (8) making certain that the side
withthehigh circular protrusionisaway from thespring.
4. Manuallydepress and holdthe spring retainer(7) in the
piston(2), theninstall theretaining ring (6) making cer-
tain it is completely seated in its groove in the piston
(2).
5. Installthe o-rings (15)on both valveassemblies (13).
6. Installthe valve spring (14) inthe piston(2), then install
thevalve assembly (13)in thespring.
7. Installtheo-ring (12) intotheo-ring groove ofpiston (2),
then install the valve seat (11) on the valve assembly
(13). Gently depress and hold the valve seat in the pis-
ton(2)while installingthespecial beveled retainingring
(10).
Important: The beveled retaining ring (10) must be in-
stalled with its flat side against the valve seat (11) and
itsbeveledsidevisible.Makecertain the beveledretain-
ing ring (10) is completely seated in its groove in the
piston(2).
8. Installthe o-rings (3 & 5)on theprimary piston(2), then
installthewearrings (4) in theo-ringgroovesnext to the
o-rings.Makecertainthatone flange of the angular wear
ring(4)is intheo-ring groove,whilethe opposite flange
extendsaway from theend ofthe piston (2) and toward
thecenter.Thewearringflangemustnot cover orover-
lap either o-ring.
9. Carefullyinsert the assembledprimarypiston (2),valve
end first, into the upper valve body until the piston
retainingringgroove in thebodyis visible.Makecertain
theo-rings(3&5)andwearrings(4)arenotdamagedin
the process. Do not force the piston. If substantial
resistanceis encountered, checkfor properinstallation
ofthe wear rings.
10. Install the piston retaining ring (1) in its groove in the
upperbody,makingcertainitisfullyseatedin thegroove.
11. Install the plunger (21) in its return spring (22). Install
the spring and plunger on the secondary piston (18).
Whilemanuallydepressingandholding the plungerand
spring on the piston, slide the plunger and spring
retainer(23) intoplacesothatitsecuresboththe plunger
andspringtothepiston.Makecertaintheretainerflanges
aresecurelyaround piston lipand plunger groove.
12. Install the o-rings (19 & 20) on the secondary piston
(18).
13. Install the exhaust diaphragm (25) on the lower body
andsecure it usingdiaphragm retainer(24).
Note:SomeE-12™&E-15™brakevalveshavethreaded
exhaust ports in lieu items 24 & 25.
14. Installthevalve spring (14)inthelowerbody,then install
thevalve assembly (13)in thespring.
15. Install theo-ring (12)into theo-ring grooveof piston(2),
then install the valve seat (11) on the valve assembly
(13).Gentlydepressandholdthevalveseatinthe lower
body while installing the special beveled retaining ring
(10).
Important: The beveled retaining ring (10) must be in-
stalled with its flat side against the valve seat (11) and
itsbeveled side visible.
Makecertainthebeveledretainingring(10)iscompletely
seated in its groove in the lower body.
16. Install the assembled secondary piston (18) in the up-
per body making certain that the o-rings (19 & 20) are
not damaged in the process.
17. Install the o-ring (17) on the upper body. Join the as-
sembled upper and lower body halves noting the
relationship marked in Disassemblystep 2.Secure the
bodyhalvestogetherusingthefour1/4"capscrews(16)
and torque to 30 to 60 pound inches.
18. If the brake valve is firewall mounted, install the pedal
mountingplateon thebasicbrake valve notingthe rela-
tionshipmarkedduringDisassembly step2. Secure the
mounting plate to the valve using the three 5/16" cap
screws and torque to 80 to 120 pound inches.
19. Install all air line fittings and plugs making certain
thread sealant material does not enter the valve.
VALVE INSTALLATION
1. Installtheassembled brakevalveon thevehicle.
2. Reconnect all air lines to the valve using the identifica-
tionmade duringValve Removal step1.
3. After installing the brake valve assembly, perform the
Operation&LeakageChecksbeforeplacingthe vehicle
inservice.
BW1622 © 2004 Bendix Commercial Vehicle Systems LLC. All rights reserved. 3/2004 Printed in U.S.A.