BENDIX E-10P DUAL BRAKE VALVES User manual

1
Bendix®E-8P™& E-10P™Dual Brake Valves
DESCRIPTION
Refer to Figures 4, 5 and 6 for item numbers referenced
in parenthesis.
The Bendix®E-8P™(Figure 1) and E-10P™(Figure 2)
dual brake valves are floor mounted, treadle operated
type brake valves with two separate supply and delivery
circuitsforservice(primaryandsecondary)braking,which
providesthedriverwitha graduatedcontrolfor applyingand
releasing the vehicle brakes.
The E-10P™dual brake valve (Figure 2) is similar to the
E-8P™dual brake valve except that a metal coil spring
(5) housed in an upper body assembly replaces the
rubber spring (27) used in the E-8P™valve. The use
of a metal coil spring (and the upper body assem-
bly) provides greater treadle travel and, therefore,
provides the driver with a less sensitive “feel” when
making a brake application. The E-10P™dual brake
valve is generally used on buses, where smooth brake
applications contribute to passenger comfort.
The circuits in the E-8P™/E-10P™dual brake valves are
identified as follows: The No. 1 or primary circuit is that
portionofthe valve between the springseatwhichcontacts
the plunger and the relay piston; the No. 2 or secondary
circuit is that portion between the relay piston and the
exhaust cavity.
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
operation to a relay valve.
Bothprimaryandsecondarycircuitsofthebrakevalveuse
a common exhaust protected by an exhaust diaphragm.
FIGURE 1 - E-8P™DUAL BRAKE VALVE FIGURE 2 - E-10P™DUAL BRAKE VALVE
VALVE
MOUNTING
PLATE
TREADLE
SUPPLY
DELIVERY
(4)
AUXILIARY
SUPPLY
VALVE
MOUNTING
PLATE
TREADLE
DELIVERY
(4)
SUPPLY
(4)
EXHAUST EXHAUST
SD-03-830

2
16
21
17
20
19 18
24
23
22
25
26
28 27
31
33
30
32
15
SUP - 1
LOWER BODY
11
10 EXHAUST COVER
ATTACHING SCREWS
BODY ATTACHING
SCREWS
13
12
FIGURE 3 - TYPICAL PIPING SCHEMATIC
TP-5™TRACTOR
PROTECTION VALVE
MV-3™
MANIFOLD
VALVE
BRAKE
CHAMBER
SLACK
ADJUSTER
COMPRESSOR
SUPPLY
RESERVOIR
(WETTANK) #1 SERVICE
RESERVOIR #2 SERVICE
RESERVOIR
DOUBLE
CHECK
VALVE
SPRING
BRAKES
SLACK
ADJUSTER
TRAILER
CONTROL
VALVE
AIR DRYER
GOVERNOR
(E-8P™OR E-10P™)
DUALBRAKE
VALVE
BP-R1™
BOBTAIL
PROPORTIONING
VALVE
QUICK
RELEASE
VALVE
9
FIGURE 4 - E-8P™DUAL BRAKE VALVE SECTIONAL VIEW
UPPER BODY
SUP - 2
DEL - 1
DEL - 2
14

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BALANCED: NO. 2 OR SECONDARY CIRCUIT
When the air pressure on the delivery side of the relay
piston(20)approachesthatbeingdeliveredontheprimary
side of the relay piston, the relay piston moves closing the
secondary inlet valve and stopping further flow of air from
the supply line through the valve. The exhaust remains
closed as the secondary delivery pressure balances the
primary delivery pressure.
When applications in the graduating range are made, a
balanced position in the primary circuit is reached as the
air pressure on the delivery side of the primary piston (22)
equalstheeffortexerted by the driver’sfooton the treadle.
A balanced position in the secondary portion is reached
whenairpressureon the secondary side of therelaypiston
(20) closely approaches the air pressure on the primary
side of the relay piston.
Whenthebrake treadle is fully depressed,boththeprimary
and secondary inlet valves remain open and full reservoir
pressure is delivered to the actuators.
RELEASING: NO. 1 OR PRIMARY CIRCUIT
With the brake treadle released, mechanical force is
removed from the spring seat (26), graduating spring (23),
andprimary piston(22).Airpressure andspringload moves
the primary piston, opening the primary exhaust valve,
allowingairpressureintheprimarydeliverylinetoexhaust
out the exhaust port.
RELEASING: NO. 2 OR SECONDARY CIRCUIT
With the brake treadle released, air is exhausted from the
primary circuit side of the relay piston (20). Air pressure
andspringload move therelaypiston,openingthe second-
ary exhaust valve, allowing air pressure in the secondary
delivery line to exhaust out the exhaust port.
PREVENTIVE MAINTENANCE
Important: Review the Bendix Warranty Policy before
performing any intrusive maintenance procedures. A
warranty may be voided if intrusive maintenance is
performed during the warranty period.
No two vehicles operate under identical conditions, as
a result, maintenance intervals may vary. Experience is
a valuable guide in determining the best maintenance
interval for air brake system components. At a minimum,
the E-8P™or E-10P™valve should be inspected every 6
months or 1500 operating hours, whichever comes first,
for proper operation. Should the E-8P™or E-10P™valve
notmeettheelementsoftheoperationaltestsnoted in this
document, further investigation and service of the valve
may be required.
Visuallycheck forphysicaldamagetothebrake valve such
as broken air lines and broken or missing parts.
OPERATION - Refer to Figure 3
APPLYING: NORMAL OPERATION - NO. 1 OR
PRIMARY CIRCUIT PORTION
When the brake treadle is depressed, the plunger exerts
force on the spring seat (26), graduating spring (23), and
primarypiston(22).The primary piston, whichcontainsthe
exhaust valve seat, closes the primary exhaust valve. As
the exhaust valve closes, the primary inlet valve is moved
off its seat allowing primary air to flow out the No. 1 or
primary delivery port.
APPLYING: NORMAL OPERATION - NO. 2 OR
SECONDARY CIRCUIT
When the primary inlet valve (33) is moved off its seat, air
is permitted to pass through the bleed passage and enters
the relay piston cavity. The air pressure moves the relay
piston(20), whichcontainstheexhaust seat,andcloses the
secondary exhaust valve.As the secondary exhaust valve
closes,theinletvalve(13) is moved offitsseatallowing the
secondary air to flow out the delivery of the same circuit.
Because of the small volume of air required to move the
relaypiston(20), action ofthesecondarycircuitof the valve
is almost simultaneous with the primary circuit portion.
APPLYING: LOSS OF AIR IN THE NO. 2 OR
SECONDARY CIRCUIT
Should air be lost in the No. 2 or secondary circuit, the No.
1 or primary circuit will continue to function as described
above under Normal Operation: No. 1 or Primary Circuit
Portion.
APPLYING: LOSS OF AIR IN THE NO. 1 OR
PRIMARY CIRCUIT
Should air be lost in the primary circuit, the function will be
as follows: As the brake treadle is depressed and no air
pressureis presentinthe primarycircuitsupply anddelivery
ports, the primary piston (22) will mechanically move the
relay piston (20), allowing the piston to close the second-
ary exhaust valve and open the secondary inlet valve and
allow air to flow out the secondary delivery port.
BALANCED: NO. 1 OR PRIMARY CIRCUIT
When the primary delivery pressure acting on the primary
piston (22) equals the mechanical force of the brake pedal
application, the primary piston (22) will move and the
primary inlet valve (33) will close, stopping further flow
of air from the primary supply line through the valve. The
exhaust valve remains closed preventing any escape of
air through the exhaust port.

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Every 3 months, 25,000 miles, or 900 operating
hours:
Clean any accumulated dirt, gravel, or foreign material
awayfromthe heel of thetreadle,plungerboot, and mount-
ing plate.
Lubricate the treadle roller, roller pin, and hinge pin, with
Barium grease per BW-204-M (Bendix part 246671).
Check the rubber plunger boot for cracks, holes, or dete-
rioration and replace if necessary. Also, check mounting
plate and treadle for integrity.
Applyathin layer ofBariumgrease,per BW-204-M(Bendix
part 246671), between plunger and mounting plate – do
not over oil!
SERVICE CHECKS
OPERATING CHECK
Checkthedelivery pressure ofbothprimaryand secondary
circuits using accurate test gauges. Depress the treadle
to several positions between the fully released and fully
appliedpositions,andcheckthe delivered pressure on the
testgaugestosee that it varies equally andproportionately
with the movement of the brake pedal.
After a full application is released, the reading on the test
gauges should fall off to zero promptly. It should be noted
that the primary circuit delivery pressure will be about 2
PSI greater than the secondary circuit delivery pressure
with both supply reservoirs at the same pressure. This is
normal for this valve.
Important:Achange in vehiclebrakingcharacteristicsora
low pressure warning may indicate a malfunction in one or
the other brake circuit, and although the vehicle air brake
system may continue to function, the vehicle should not
be operated until the necessary repairs have been made
and both braking circuits, including the pneumatic and
mechanical devices, are operating normally. Always
check the vehicle brake system for proper operation after
performing brake work and before returning the vehicle
to service.
LEAKAGE CHECK
1. Make and hold a high pressure (80 psi) application.
2. Coat the exhaust port and body of the brake valve with
a soap solution.
3. Leakage permitted is a 1" bubble in 3 seconds. If the
brake valve does not function as described above or
leakage is excessive, it is recommended that it be
replacedwitha new orremanufacturedunit,orrepaired
with genuine Bendix parts available at authorized
Bendix parts outlets.
Refer to figures 4, 5 and 6 for item numbers referenced
in parenthesis.
REMOVAL
1. Chock the vehicle wheels or park the vehicle by
mechanical means. (Block and hold vehicle by means
other than air brakes.) Drain all air system reservoirs.
2. Identify and disconnect all supply and delivery lines at
the brake valve.
3. Remove the brake valve and treadle assembly from
the vehicle by removing the three cap screws on the
outer bolt circle of the mounting plate. The basic brake
valvealonecanberemovedbyremovingthethreecap
screws on the inner bolt circle.
DISASSEMBLY (Figures 4, 5 and 6)
1. If the entire brake valve and treadle assembly was
removed from the vehicle, remove the three cap
screws securing the treadle assembly to the basic
brake valve.
2. Removethescrew(9)securing the exhaust diaphragm
(10) and washer (11) to the exhaust cover (12).
3. Removethefour screws that secure the exhaust cover
(12) to the lower body.
4. Remove the secondary inlet and exhaust valve
assembly (13) from the lower body.
5. Remove the four hex head cap screws securing the
lower body to the upper body and separate the body
halves.
6. Remove the rubber seal ring (14) from the lower
body.
7. For E-8P™valve only: Whileapplyingthumbpressure
to the primary piston (22), lift out and up on the three
lock tabs of the primary piston retainer (15).
8. For E-10P™valve only: While depressing spring seat
(7), remove retaining ring (8). Remove spring seat (7)
and coil spring (5).
Caution:Before proceeding withthedisassembly,refer
to Figures 3 and 4 and note that the lock nut (16) and
stem (17) are used to contain the primary piston return
spring(for E-8P™valve: 23,forE-10P™valve: 6), stem
spring (19), and the relay piston spring (21). The com-
binedforce of thesespringsis approximately50pounds
and care must be taken when removing the lock nut as
the spring forces will be released. It is recommended
that the primary piston and relay piston be manually
or mechanically contained while the nut and stem are
being removed.
9. Using a 3/8” wrench, hold the lock nut (16) on the
threaded end of the stem (17). Insert a screwdriver to
restrainthestem,remove the lock nut (16), springseat,
(18) and stem spring (19).
10.For E-10P™valve only: Remove adapter (1)ando-ring
(4). Removethe primarypiston(2)from adapter(1)and
o-ring (34) from the primary piston (2).

5
bw
bw
FIGURE 5 - E-8P™DUAL BRAKE VALVE - EXPLODED
VIEW FIGURE 6 - E-10P™DUAL BRAKE VALVE - EXPLODED VIEW

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11. Remove the relay piston (20), relay piston spring (21),
primarypiston(E-8P™valve: 22,E-10P™valve: 2)and
primary piston return spring (E-8P™valve: 23, E-10P™
valve: 6) from the upper body. Use care so as not to
nick seats.
12. A small washer (24) will be found in the cavity of the
lower side of the primary piston (for E-8P™valve:22,
for E-10P™valve: 2).
13.For E-8P™valve only: Disassemble the primary piston
by rotating the spring seat nut (25) counterclockwise.
Separate the spring seat nut, spring seat (26), and
rubber spring (27) and remove the piston o-ring (28).
14.Remove the large and small o-rings (30 & 31) from the
relay piston (20).
15.Remove the retaining ring (32) securing the primary
inlet and exhaust valve assembly (33) in the upper
body and remove the valve assembly.
CLEANING AND INSPECTION
1. Wash all metal parts in mineral spirits and dry.
2. Inspect all parts for excessive wear or deterioration.
3. Inspect the valve seats for nicks or burrs.
4. Check the springs for cracks or corrosion.
5. Replace all rubber parts and any part not found to be
serviceableduringinspection, use only genuine Bendix
replacement parts.
ASSEMBLY
Prior to reassembling, lubricate all o-rings, o-ring grooves,
piston bores, and metal to metal moving surfaces with
Dow Corning 55 o-ring lubricant (Bendix piece number
291126).
Note: All torques specified in this manual are assembly
torques and can be expected to fall off, after assembly is
accomplished.Donot retorqueafterinitialassemblytorques
fall.
1. Install the primary inlet and exhaust assembly (33) in
the upper body and replace the retaining ring (32) to
secureit. Be suretheretaining ringisseatedcompletely
in its groove.
2. Installthelargeandsmallo-rings(30 & 31) on the relay
piston (20).
3. For E-8P™valve only: Installo-ring(28) in the primary
piston (22) o-ring groove.
4. For E-8P™valve only: Install the rubber spring (do
not lubricate) (27), concave side down in the primary
piston (22) and place the spring seat (26), flat side up,
over the rubber spring.
5. For E-8P™valve only: Installtheprimarypistonspring
seatnut(25),with its hex closest tothespringseat,and
rotate clockwise until the top surface of the spring seat
is even with the top surface of the piston. Set aside.
6. Place relay piston spring (21) in concave portion of
relaypiston(20) and installrelaypistonthrough primary
inlet/exhaust assembly (33) into under side of upper
body.
7. For E-10P™valve only: Installo-ring(4)on adapter (1)
andinstall adapter on upper body. Install o-ring (34) on
primary piston (2).
8. Place screwdriver, blade up, in vise. Insert stem (17)
throughthe relay pistonupperbodysub assembly, slide
thisassembly overtheblade ofthesecuredscrewdriver,
engage the screwdriver blade in the slot in the head of
the stem.
9. Place the washer (24) over the stem (17) and on top
of the relay piston (20).
10.Install primary return spring (E-8P™valve: 23, E-10P™
valve: 6) in upper body piston bore.
11. For E-8P™valve only: Installtheprimarypistonrubber
spring sub assembly (steps 4 & 5) over the stem, into
the upper body piston bore. For E-10P™valve: Install
primary piston sub-assembly (reference step 7).
12.Compress piston(s) (For E-8P™valve: the relay piston
(20), for E-10P™valve: the primary and relay pistons
(2 & 20)) and retaining ring into the upper body from
either side and hold compressed, either manually or
mechanically. See the cautionary note under step 8
in the Disassembly section of this manual.
13.Place the stem spring (19) (E-8P™valve: place over
the spring seat nut (25)), the spring seat (18) (concave
side up) and lock nut (16) on the stem (17). Torque to
20 - 30 inch pounds.
14.For E-8P™valve only: Install the primary piston
retainer (15) over the piston, making certain all three
lock tabs have engaged the outer lip of the body.
15. For E-10P™valve only: Install coil spring (5), spring
seat (7), and retaining ring (8) .
16. Replace the rubber seal ring (14) on the lower body.
17. Install the 4 hex head cap screws securing the
lower body to the upper body. Torque to 30 - 60 inch
pounds.
18.Installthesecondaryinlet and exhaust valve assembly
(13) on the lower body.
19.Installthescrews that secure the exhaust cover (12) to
the lower body. Torque to 20 - 40 inch pounds.
20. Secure the screw (9) holding the exhaust diaphragm
(10) and the diaphragm washer (11) to the exhaust
cover (12). Torque to 5 - 10 inch pounds.
21.Install all airlinefittingsand plugsmakingcertain thread
sealant material does not enter valve.

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VALVE INSTALLATION
1. Install the assembled brake valve on the vehicle.
2. Reconnect all air lines to the valve using the identifica-
tion made during VALVE REMOVAL step 1.
3. After installing the brake valve assembly, perform
the “OPERATION AND LEAKAGE CHECKS” before
placing the vehicle in service.
GENERAL SAFETY GUIDELINES
WARNING! PLEASE READ AND FOLLOW
THESEINSTRUCTIONSTOAVOIDPERSONAL
INJURY OR DEATH:
Whenworkingon or aroundavehicle,thefollowing general
precautions should be observed at all times.
1. Park the vehicle on a level surface, apply the park-
ing 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 work-
ing in the engine compartment, the engine should
be shut off and the ignition key should be removed.
Where circumstances require that the engine be in
operation, EXTREME CAUTION 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 proce-
dures. 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 sys-
tems, 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 dryer system or a dryer reservoir module, be
sure to drain the purge reservoir.
5. Following the vehicle manufacturer’s recommend-
ed 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 weld-
ing 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.

8BW2066 © 2007 Bendix Commercial Vehicle Systems LLC. All rights reserved. 8/2007 Printed in U.S.A.