Bendix

®

E-8P

™

& E-10P

™

Dual Brake Valves

TREADLE

TREADLE

MOUNTING

PLATE

MOUNTING

PLATE

SUPPLY

VALVE

SUPPLY

(4)

DELIVERY

(4)

DELIVERY

(4)

VALVE

AUXILIARY

SUPPLY

EXHAUST

FIGURE 1 - E-8P ™ DUAL BRAKE VALVE

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 fl oor mounted, treadle operated type brake valves with two separate supply and delivery circuits for service (primary and secondary) braking, which provides the driver with a graduated control for applying and 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 assembly) provides greater treadle travel and, therefore, provides the driver with a less sensitive “feel” when making a brake application. The E-10P ™ dual brake

EXHAUST

FIGURE 2 - E-10P ™ DUAL BRAKE VALVE 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 identifi ed as follows: The No. 1 or primary circuit is that portion of the valve between the spring seat which contacts 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.

Both primary and secondary circuits of the brake valve use a common exhaust protected by an exhaust diaphragm.

1

SLACK

ADJUSTER

TRAILER

CONTROL

VALVE

BRAKE

CHAMBER

(E-8P ™ OR E-10P

DUAL BRAKE

VALVE

™ )

MV-3 ™

MANIFOLD

VALVE

TP-5 ™ TRACTOR

PROTECTION VALVE

SLACK

ADJUSTER

SPRING

BRAKES

GOVERNOR

AIR DRYER

DOUBLE

CHECK

VALVE

QUICK

RELEASE

VALVE

BP-R1 ™

BOBTAIL

PROPORTIONING

VALVE

COMPRESSOR

SUPPLY

RESERVOIR

(WET TANK)

#1 SERVICE

RESERVOIR

FIGURE 3 - TYPICAL PIPING SCHEMATIC

15

19

16

27

28

23

18

#2 SERVICE

RESERVOIR

25

26

22

UPPER BODY

SUP - 1

20

30

24

17

33

DEL - 1

31

21

14

LOWER BODY

32

SUP - 2

13

10

11

9

FIGURE 4 - E-8P ™ DUAL BRAKE VALVE SECTIONAL VIEW

2

12

BODY ATTACHING

SCREWS

DEL - 2

EXHAUST COVER

ATTACHING SCREWS

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 primary piston (22). The primary piston, which contains the 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 fl ow 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), which contains the exhaust seat, and closes the secondary exhaust valve. As the secondary exhaust valve closes, the inlet valve (13) is moved off its seat allowing the secondary air to fl ow out the delivery of the same circuit.

Because of the small volume of air required to move the relay piston (20), action of the secondary circuit of 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 pressure is present in the primary circuit supply and delivery ports, the primary piston (22) will mechanically move the relay piston (20), allowing the piston to close the secondary exhaust valve and open the secondary inlet valve and allow air to fl ow 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 fl ow of air from the primary supply line through the valve. The exhaust valve remains closed preventing any escape of air through the exhaust port.

BALANCED: NO. 2 OR SECONDARY CIRCUIT

When the air pressure on the delivery side of the relay piston (20) approaches that being delivered on the primary side of the relay piston, the relay piston moves closing the secondary inlet valve and stopping further fl ow 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) equals the effort exerted by the driver’s foot on the treadle.

A balanced position in the secondary portion is reached when air pressure on the secondary side of the relay piston

(20) closely approaches the air pressure on the primary side of the relay piston.

When the brake treadle is fully depressed, both the primary 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), and primary piston (22). Air pressure and spring load moves the primary piston, opening the primary exhaust valve, allowing air pressure in the primary delivery line to exhaust 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 and spring load move the relay piston, opening the secondary 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 fi rst, for proper operation. Should the E-8P ™ or E-10P ™ valve not meet the elements of the operational tests noted in this document, further investigation and service of the valve may be required.

Visually check for physical damage to the brake valve such as broken air lines and broken or missing parts.

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Every 3 months, 25,000 miles, or 900 operating hours:

Clean any accumulated dirt, gravel, or foreign material away from the heel of the treadle, plunger boot, and mounting 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 deterioration and replace if necessary. Also, check mounting plate and treadle for integrity.

Apply a thin layer of Barium grease, per BW-204-M (Bendix part 246671), between plunger and mounting plate – do not over oil!

SERVICE CHECKS

OPERATING CHECK

Check the delivery pressure of both primary and secondary circuits using accurate test gauges. Depress the treadle to several positions between the fully released and fully applied positions, and check the delivered pressure on the test gauges to see that it varies equally and proportionately 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: A change in vehicle braking characteristics or a 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 replaced with a new or remanufactured unit, or repaired with genuine Bendix parts available at authorized

Bendix parts outlets.

Refer to fi gures 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 valve alone can be removed by removing the three cap 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. Remove the screw (9) securing the exhaust diaphragm

(10) and washer (11) to the exhaust cover (12).

3. Remove the four 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: While applying thumb pressure 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 with the disassembly, 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, for E-10P ™ valve: 6), stem spring (19), and the relay piston spring (21). The combined force of these springs is approximately 50 pounds 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 restrain the stem, remove the lock nut (16), spring seat,

(18) and stem spring (19).

10. For E-10P ™ valve only: Remove adapter (1) and o-ring

(4). Remove the primary piston (2) from adapter (1) and o-ring (34) from the primary piston (2).

4

bw bw

FIGURE 5 - E-8P ™ DUAL BRAKE VALVE - EXPLODED

VIEW

FIGURE 6 - E-10P ™ DUAL BRAKE VALVE - EXPLODED

VIEW

5

11. Remove the relay piston (20), relay piston spring (21), primary piston (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 serviceable during inspection, 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 specifi ed in this manual are assembly torques and can be expected to fall off, after assembly is accomplished. Do not retorque after initial assembly torques fall.

1. Install the primary inlet and exhaust assembly (33) in the upper body and replace the retaining ring (32) to secure it. Be sure the retaining ring is seated completely in its groove.

2. Install the large and small o-rings (30 & 31) on the relay piston (20).

3. For E-8P ™ valve only: Install o-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), fl at side up, over the rubber spring.

5. For E-8P ™ valve only: Install the primary piston spring seat nut (25), with its hex closest to the spring seat, and rotate clockwise until the top surface of the spring seat is even with the top surface of the piston. Set aside.

6

6. Place relay piston spring (21) in concave portion of relay piston (20) and install relay piston through primary inlet/exhaust assembly (33) into under side of upper body.

7. For E-10P ™ valve only: Install o-ring (4) on adapter (1) and install adapter on upper body. Install o-ring (34) on primary piston (2).

8. Place screwdriver, blade up, in vise. Insert stem (17) through the relay piston upper body sub assembly, slide this assembly over the blade of the secured screwdriver, 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: Install the primary piston rubber 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. Install the secondary inlet and exhaust valve assembly

(13) on the lower body.

19. Install the screws 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 air line fi ttings and plugs making certain thread sealant material does not enter valve.

VALVE INSTALLATION

1. Install the assembled brake valve on the vehicle.

2. Reconnect all air lines to the valve using the identifi cation 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.

brake system, or any auxiliary pressurized air systems, 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.

GENERAL SAFETY GUIDELINES

WARNING! PLEASE READ AND FOLLOW

THESE INSTRUCTIONS TO AVOID PERSONAL

INJURY OR DEATH:

When working on or around a vehicle, the following general precautions should be observed at all times.

ed procedures, deactivate the electrical system in a manner that safely removes all electrical power from the vehicle.

pressures. ing brakes, and always block the wheels. Always wear safety glasses. containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.

Use only genuine Bendix ® replacement parts, components and kits. Replacement hardware, tubing, hose, fi ttings, etc. must be of equivalent size, type and strength as original equipment and be designed specifi cally for such applications and systems.

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 be in operation, EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated or electrically charged components.

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.

parts should be replaced rather than repaired. Do not attempt repairs requiring machining or welding unless specifi cally 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.

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.

7

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