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10

DISASSEMBLY

GENERAL

The following disassembly and assembly procedure is
presented for reference purposes only and presupposes
that the appropriate maintenance kit is on hand at the time
of disassembly. The instructions provided with the
maintenance kit should always be used in lieu of those
presented here. Refer to figure 10 throughout the disassembly
and assembly procedure. CAUTION: The AR-2

 valve may

be lightly clamped in a bench vise during disassembly,
however, over clamping will cause damage to the valve and
result in leakage and/or malfunction. If a vise is to be used,
position the valve so that the jaws bear on the supply ports
on opposing sides of the valve’s body.

1. Remove all air fittings and plugs from the AR-2

 valve.

2. Mark the relationship of the antilock electronic controller

(2) and valve cover (4) to the body (9). Note the position
of the mounting bracket (6) and mark the relationship of
the bracket to the valve body (9), cover (4), and antilock
controller (2). Remove and retain the four cap screws
and lock washers (1) that secure the controller to the
cover (4), then carefully remove the electronic controller
without damaging its gasket (3).

3. While holding the exhaust cover (11), remove the retaining

ring (10) that secures it to the body (9).

4. Remove the exhaust cover (11) along with both o-rings

(12 & 13).

5. Remove the valve spring (14), valve retainer (15), and

the valve assembly (16) from the body (9).

6. Remove and retain the two cap screws and lock washers

(5) that secure the bracket (6) to the cover (4). Remove
and retain the two bolts with lock washers (7), and nuts
(8) that secure the cover (4) and mounting bracket to
the valve body (9). Then remove the remaining two cap
screws (7) that secure the cover (4) to the body (9).

7. Separate the cover (4) and mounting bracket (6) from

the body (9), then remove the large and small sealing
rings (19 & 40).

8. Remove and retain the relay piston (17) and relay piston

spring (if present) from the body (9). NOTE: The relay
piston spring is not used in all AR-2

 valves.

9. Remove the o-ring (18) from the relay piston (17).

10. Remove the retaining ring (20) from the cover (4), then

remove the exhaust piston (21).

11. Remove the exhaust piston o-ring (22).

12. Remove the service piston (23) from the cover (4).

13. Remove the spring (24) and spring cage (25) from the

cover (4).

14. Remove the blend back piston (26) from the valve cover

(4), then remove both o-rings (27 & 28).

15. Remove the proportioning piston (30) from the valve cover

(4), then remove both o-rings (29 & 31).

16. While holding the inlet valve seat (34) in place, remove

the retaining ring (36) from the proportioning piston (30).

17. Remove the inlet valve seat (34), the inlet valve (33),

and the valve spring (32) from the proportioning piston
(30), then remove the o-ring (35) from the valve seat (34).

18. Remove the exhaust diaphragm screw (37), washer (38)

and exhaust diaphragm (39) from the cover (4).

CLEANING & INSPECTION

1. Using mineral spirits or an equivalent solvent, clean and

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
portion of the body (9) and cover (4) is acceptable.
Replace the entire valve if the interior of the body or
cover exhibit signs of corrosion or pitting.

3. Inspect the bores of both the body (9) and cover (4) for

deep scuffing or gouges. Replace the entire valve if
either are found.

4. Make certain all air channels and exhaust passages in

the valve cover (4) are clear and free of obstruction.

5. Inspect the pipe threads in the body (9). Make certain

they are clean and free of thread sealant.

6. Wash all non-metallic components in a soap and water

solution making certain to rinse and dry thoroughly.
Inspect each non-metallic component for cracks, wear
or distortion. Replace the entire valve if these conditions
are found.

7. If the valve was equipped with a relay piston spring,

inspect it for signs of corrosion, pitting and cracks.
Replace as necessary.

8. Inspect all air line fittings for corrosion and replace as

necessary. Make certain to remove all old thread sealant
before reuse.

ASSEMBLY

1. Prior to assembly, lubricate all o-rings, seals, and pistons,

as well as body and cover bores, using the lubricant
provided with the Bendix maintenance kit.

2. Install the o-ring (35) on the inlet valve seat (34).

3. Insert the inlet and exhaust valve spring (32), LARGE

END FIRST, into the proportioning piston (30).

4. Install the inlet and exhaust valve (33) inside the inlet

valve seat (34) making certain that the four tabs are
within the bore of the seat.

Содержание AR-2 ANTILOCK RELAY VALVE

Страница 1: ...he standard relay valve used to control the rear axle service brakes and performs the standard relay function during tractor trailer operation During tractor bobtail operation theAR 2 valve reduces brake application pressure to the lighter rear axle s brakes to improve vehicle controllability and minimize rear axle s wheel skid before antilock is required TheAR 2 valve provides added vehicle braki...

Страница 2: ...5 covering the EC 15 electronic controller Other useful information regarding antilock system components used in conjunction with the AR 2 valve is contained in publications SD 13 4793 covering the M 21 antilock modulator and SD 13 4754 covering the WS 20 wheel speed sensor INITIAL CHARGING During the initial build up of tractor system air pressure reservoir air flows into the supply port and thro...

Страница 3: ... and neither increases nor decreases SERVICE BRAKES RELEASING TRACTOR TRAILER COMBINATION When the brake application is released air from above the relay piston flows back through the proportioning blend back and service pistons to the foot brake valve and is exhausted As air pressure is reduced above the relay piston pressure beneath it lifts the piston away from the exhaust valve and opens the e...

Страница 4: ...ning will occur for all service applications between approximately 30 and 80 psi Service applications of more than 80 psi cause the blend back piston to begin to move Service air pressure acting on the full diameter of the blend back piston over comes the resistance of reservoir pressure acting on the large diameter of the other side Above 80 psi the ratio between control and delivered air pressur...

Страница 5: ... damage Replace as necessary 3 Test air line fittings for excessive leakage and tighten or replace as necessary 4 Perform the Leakage Test described in this manual EVERY YEAR 100 000 MILES OR 3 600 OPERATING HOURS 1 Perform the Operation and Leakage Tests described in this manual WARNING PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH When working on or around a vehicle...

Страница 6: ...TOR TRAILER SUPPLY VALVE INLET CLOSED EXHAUST CLOSED REARAXLESERVICE CHAMBER SERVICE BRAKE VALVE ANTILOCK CONTROLLER INLET CLOSED EXHAUST CLOSED M 21 MODULATOR BLENDBACK PISTON PROPORTIONING PISTON RELAYPISTON TRAILER SUPPLY VALVE REARAXLESERVICE CHAMBER SERVICE BRAKE VALVE ANTILOCK CONTROLLER M 21 MODULATOR ...

Страница 7: ...red octagonal button and system park control dash control w yellow diamond button activated for tractor trailer operation apply and release the brakes several times and check for prompt application and release at each wheel If prompt reaction is noted at some but not all wheels test the M 21 antilock modulator between the AR 2 valve and the brake chamber for proper operation If a sluggish response...

Страница 8: ...where it joins the body The leakage noted should not exceed a 1 bubble in less than 3 seconds at any exhaust port with no leakage detected between the cover and body VALVE REMOVAL 1 Park the vehicle on a level surface and block the wheels and or hold the vehicle by means other than the air brakes 2 Drain the air pressure from all vehicle reservoirs 3 Identify mark or label all air lines and wiring...

Страница 9: ...9 FIGURE 10 AR 2 ANTILOCK RELAY VALVE 1 2 3 30 32 34 36 35 33 31 7 6 5 29 27 25 24 26 28 4 19 17 40 18 39 38 37 8 20 22 21 23 15 13 11 14 12 10 16 9 ...

Страница 10: ...e the service piston 23 from the cover 4 13 Remove the spring 24 and spring cage 25 from the cover 4 14 Remove the blend back piston 26 from the valve cover 4 then remove both o rings 27 28 15 Remove the proportioning piston 30 from the valve cover 4 then remove both o rings 29 31 16 While holding the inlet valve seat 34 in place remove the retaining ring 36 from the proportioning piston 30 17 Rem...

Страница 11: ...iner 15 surrounds the rubber portion of the valve Install the inlet and exhaust valve in the body 9 17 Install the inlet and exhaust valve return spring 14 in the body 9 18 Install the large and small diameter o rings 13 12 in the cover 11 then install the exhaust cover in the body 9 taking care not to damage the o rings Hold the exhaust cover in place 19 While depressing the exhaust cover 11 inst...

Страница 12: ...12 BW1672 2004 Bendix Commercial Vehicle Systems LLC All rights reserved 6 2004 Printed in U S A ...

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