19
FORM NO. L-20063-AG-1216
16. Ream the new Bearings (Items 14 and 15) to fit the
Pivot Pins (Item 7).
17. Reinstall the Pivot Pins (Item 7).
18. Reinstall the Pivot Pin Retainer Plate (Item 6).
19. Reinstall the four Cap Screws (Item 24) to secure Pivot
Pin Retainer Plate (Item 6).
20. Tighten the four Cap Screws (Item 24) to 7.0-9.2 Nm
[5-7 ft-lb] torque.
21. Slide the Friction Facings (Item 4) and Shoes (Item 3)
onto the Arms (Item 2).
22. Reinstall the Shoe Pins (Item 16).
23. Reinstall the Spring Retainers (Item 5) and Return
Springs (Item 17) onto the Arms (Item 2).
24. Screw the Actuator (Item 11) back onto the Arm (Item
2).
25. Screw the Adjustment Screw (Item 8) and the Spanner
Nut (Item 12) onto the other Arm (Item 2).
Note
On spring engaged BD Caliper Brakes, apply hold-off
air pressure and:
Refer to pages 16 & 17 for Manual Disengagement and
Re-Engagement instructions.
26. Perform Friction Facing adjustment (See FRICTION
FACING CLEARANCE ADJUSTMENT).
DIAPHRAM REPLACEMENT
The diaphragm, part #1555, is the air seal in the service
chamber of the Spring/Air actuator and the Air Actuator.
(See Figure 18).
Air/Spring Actuator:
1. Make sure the Air/Spring Actuator is manually released:
Refer to pages 16 & 17 for Manual Disengagement and
Re-Engagement instructions.
2. Use a spanner wrench to loosen the spanner nut and
unscrew the Spring/Air Actuator from the brake arm.
3. Using a 9/16” wrench to remove the nut on the clamp
ring. Hold the spring actuator securely in place, remove
the clamp ring and remove the spring actuator from the
service chamber.
4. Discard the old diaphragm and install a new diaphragm
in the bottom recess of the Air/Spring Actuator.
5. Position the Air/Spring Actuator onto the housing/tube
assembly and re-install clamp band.
6. Firmly tap the clamp band around its circumference
while tightening the clamp band nut to ensure proper
seating. Tighten nut to 20-25 ft.-lbs. torque.
7. Screw the actuator back into the arm and tighten the
spanner nut to 10-14 ft.-lbs.
8. Apply air pressure to the service chamber and check
for air leakage.
Refer to pages 16 & 17 for Manual Disengagement
and Re-Engagement instructions.
Refer to page 8, “FRICTION FACING CLEARANCE
ADJUSTMENT” for Air/Spring Actuator re-engagement
and facing clearance adjustments.
Air Actuator:
1. Use a spanner wrench to loosen the spanner nut and
unscrew the Air Actuator from the brake arm.
2. Using a 9/16” wrench to remove the nut on the clamp
ring. Remove the clamp ring and remove the Air Actuator
pressure cap.
3. Discard the old diaphragm and install a new diaphragm
in the pressure cap.
4. Position the pressure cap onto the housing/tube
assembly and reinstall the clamp bolt and nut.
5. Firmly tap around the circumference of the clamp ring
with a hammer to assure full seating and tighten the
nut to 25-30 ft.-lbs. torque.
6. Screw the actuator back into the arm and tighten the
spanner nut to 10-14 ft.-lbs.
7. Apply air pressure to the service chamber and check
for air leakage.
Refer to page 8, “FRICTION FACING CLEARANCE
ADJUSTMENT” for Air/Spring Actuator re-engagement
and facing clearance adjustments.
CAUTION
Working with spring loaded or tension
loaded fasteners and devices can cause
injury. Wear safety glasses and take the
appropriate safety precautions.
PARTS REPLACEMENT (continued)
REPLACEMENT OF NON-FUNCTIONING
2 & 3 PORT SPRING ACTUATORS
Never remove the spring chamber retaining ring from
a spring actuator. Improper disassembly could release
the high energy spring (with a force up to 2,700 lbs) and
cause serious bodily harm.
1. Manually release the brake. Refer to pages 16 &
17 for Manual Disengagement and Re-Engagement
instructions.
2. Remove manually disengaged actuator from the caliper
brake.
3. Order Replacement actuator. (#810493)
CAUTION
This product is spring loaded under
extreme pressure. Do not disassemble.
actuator. If actuator malfunctions, replace
actuator or contact Nexen.
