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10

DISASSEMBLY

PREPARATION FOR DISASSEMBLY

1. Remove all air fittings and plugs from the valve.

2. Mark the relationship of the valve cover (3) to the body

(4) and, if the valve is equipped with a mounting bracket
(15), mark the relationship of the bracket to the cover
and body (4).

3. Mark the relationship of the electronic controller (1) to

the cover (3).

DISASSEMBLY

The following disassembly and assembly procedure is
presented for reference purposes only.  Instructions
packaged with repair and maintenance kits should always
be followed instead of the instructions presented here.

CAUTION: The valve may be lightly clamped in a bench
vise during disassembly, however, over clamping will result
in 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 body.

1. Remove and retain the four cap screws (2) that secure

the electronic controller (1) to the cover (3), then
separate and retain the controller (1), from the cover
(3).  Note: In some instances a controller, Item 1, will
not be present and only a cover plate will be noted.
Remove the cover plate in the same manner described
for the controller.

2. While holding the exhaust cover (6), remove the

retaining ring (5) that secures it to the body (4).

3. Remove the exhaust cover( 6) along with both o-rings

(7 & 8).

4. Remove the valve spring (9), valve retainer (10), and

the valve assembly (11) from the body (4).

5. Remove and retain the two long cap screws (12) and

nuts (13) that secure the cover (3) to the body (4).

6. Remove and retain the two cap screws and lock

washers (14) that secure the bracket (15) to the cover
(4), then remove and retain the bracket.

7. Remove and retain the two short cap screws (16) that

secure the cover (3) to the body (4).

8. Separate the cover (3) from the body (4), then remove

the sealing ring (17) and o-ring (18).

9. Remove the relay piston (19) and relay piston spring

(20) from the body (4).  NOTE: The relay piston spring,
item 20 is not used in all valves.

10. Remove the o-ring (21) from the relay piston (19).

11. Remove the retaining ring (22).  Then remove check valve

seat (23), with o-rings (27 & 28).  Remove o-rings (27 &
28) from the check valve seat.

12. Remove the check valve (24), guide (25), and spring (26).

13. Remove the inlet seat (29) with o-rings (30 & 31), then

remove o-rings (30 & 31) from the inlet sea (29).

14. Remove the check valve seat (32) from the valve cover

(3).  Remove both o-ring (33).

15. Remove the check valve (34), guide (35), and spring (36).

16. Remove the primary inlet seat (37) with o-rings (38, 39 &

40), then remove o-rings (38, 39 & 40) from the primary
inlet seat (37).

17. Do not disassemble the ATR-1DC

 valve any further than

described here.

CLEANING & INSPECTION

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

thoroughly dry all metal parts.  Do not damage bores
with metal tools.

2. Wash all retained, nonmetallic components in a soap

and water solution making certain to rinse and dry
thoroughly.

3. 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 (4) and cover (3) is acceptable.  Replace the
entire valve if the interior of the body or cover exhibit
signs of corrosion or pitting.

4. Inspect each nonmetallic component for cracks, wear

or distortion.  Replace the entire valve if these conditions
are found.

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

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

6. Make certain the air channel running between the top

surface of the body (1) and its supply port is clear and
free of obstruction.

7. Make certain all air channels and exhaust passages in

the valve cover (3) are clear and free of obstruction.

8. Inspect the pipe threads in the body (4) and valve cover

(3).  Make certain they are clean and free of thread
sealant.

9. Inspect the relay piston spring (20) for signs of corrosion,

pitting and cracks.  Replace as necessary.

10. 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 silicone lubricant.

2. Install the large and small diameter o-rings (38, 39 & 40)

on the primary inlet seat (37), then insert the small
diameter of the seat (37) into the bore in the cover (3).
Do not cut or pinch the o-rings.

Summary of Contents for ATR1DC ANTILOCK TRACTION RELAY

Page 1: ...a cover plate can be installed and the antilock controller mounted elsewhere on the vehicle When an ATR 1DC valve is combined with an antilock traction controller the resulting assembly is referred to as a antilock traction assembly or AT 1DC TheATR 1DC valve replaces the standard relay valve used to control the rear axle service brakes and performs the standard relay function Like the standard re...

Page 2: ... of the antilock system and separate antilock components and their operation is not addressed in this publication For a description of antilock operation refer to the appropriate Service Data Sheet covering the electronic controller used with the ATR 1DC valve e g SD 13 4785 for the EC 16 electronic controller or SD 13 4788 for the EC 17 electronic controller Other useful information on antilock s...

Page 3: ...nse to primary control and seals the air passage leading to the secondary control Air flows past double check valve diaphragm B and through a passage in the cover to the top of the service relay piston In response TRACTION CONTROL SOLENOID SUPPLY PORT SECONDARY SERVICE PORT DOUBLE CHECK VALVE A DELIVERY PORT EXHAUST PORT RELAY PISTON INLET EXHAUST VALVE BLEND BACK PISTON SOLENOID CONNECTOR AIR BAG...

Page 4: ...re above and below the relay piston is equal the piston moves FIGURE 7 SERVICE BRAKES APPLYING PRIMARY CIRCUIT DELIVERY FAILED TRACTION CONTROL SOLENOID SUPPLY PORT SECONDARY SERVICE PORT DOUBLE CHECK VALVE A DELIVERY PORT EXHAUST PORT RELAY PISTON INLET EXHAUST VALVE BLEND BACK PISTON SOLENOID CONNECTOR AIR BAG BRAKE CHAMBER TONE RING EC 16 OR EC 17 CONTROLLER WHEEL SPEED SENSOR PRIMARY SERVICE P...

Page 5: ... control port and primary delivery circuit of the brake valve Air flows past double check valve diaphragm B and through a passage in the cover to the top of the service relay piston In response to air pressure the relay piston drain valve flexes and seals the drain passage leading to the relay exhaust Simultaneously the relay piston moves into contact with the exhaust portion of its inlet and exha...

Page 6: ... AT 1DC ANTILOCK TRACTION ASSY EC 16 OR EC 17 CONTROLLER ATR 1DC VALVE MODULATOR MODULATOR REAR AXLE BRAKE REAR AXLE BRAKE EXCITER SPEED SENSOR EXCITER SPEED SENSOR MODULATOR BRAKE CHAMBER ENGINE CONTROL MODULE ECM TRACTION SWITCH ANTILOCK DASH LAMP TRACTION DASH LAMP RETARDER SWITCH MODULATOR ...

Page 7: ...lve s exhaust port PREVENTIVE MAINTENANCE GENERAL Perform the tests and inspections presented at the prescribed intervals If theATR 1DC valve fails to function as described or leakage is excessive it should be repaired or replaced with a new or genuine Bendix remanufactured unit available at any authorized parts outlet EVERY 3 MONTHS 25 000 MILES OR 900 OPERATING HOURS 1 Remove any accumulated con...

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

Page 9: ...ery port pressure from the 10 psi service pressure to obtain the differential Compare the measured differential with the pressure specified for theATR 1DC valve part number see the l D washer also for the differential NOTE For ATR 1DC valves not incorporating a relay piston return spring 20 the measured differential should be approximately 4 psi When a spring is in use the differential will be hig...

Page 10: ...lve seat 23 with o rings 27 28 Remove o rings 27 28 from the check valve seat 12 Remove the check valve 24 guide 25 and spring 26 13 Remove the inlet seat 29 with o rings 30 31 then remove o rings 30 31 from the inlet sea 29 14 Remove the check valve seat 32 from the valve cover 3 Remove both o ring 33 15 Remove the check valve 34 guide 35 and spring 36 16 Remove the primary inlet seat 37 with o r...

Page 11: ...9 in the body 4 12 Install the large and small diameter o rings 7 8 in the exhaust cover 6 then install the exhaust cover in the body 4 taking care not to damage the o rings Hold the exhaust cover in place 13 While depressing the exhaust cover 6 install the retaining ring 5 in the body 4 Make certain the retainer 5 is fully seated in its groove in the body 14 If the valve was equipped with a relay...

Page 12: ...12 BW1969 2004 Bendix Commercial Vehicle Systems LLC All rights reserved 9 2004 Printed in U S A ...

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