Bench Test - Komatsu 830E Shop Manual

Assembly of Piston Assembly
1. Assemble inner spring guide (10, Figure 6-15),
return pin and grip assembly (8 & 9) and spring
retainer (5) loosely into piston (11).
2. Using sleeve (A), (Figure 6-6) install sleeve over
return pin against spring retainer.
3. Apply force with a press to fully compress return
spring.
4. With spring compressed, turn (clockwise direc-
tion) threaded retaining ring (2, Figure 6-15)
down against spring retainer. Use a spanner
wrench to be certain retaining ring is fully bot-
tomed.
FIGURE 6-15. PISTON ASSEMBLY
1. Lockwire Wing
2. Retaining Ring
3. O-Ring
4. Return Pin Washer
5. Spring Retainer
6. Piston Return Spring
J6-12
7. Outer Spring Guide
8. Return Pin
9. Grip Assembly
10. Inner Spring Guide
11. Piston
12. Dust Shield
Rockwell Armature Speed Rear Disc Brakes
5. Continue holding spring compression and turn
retaining ring one full turn (minimum) counter-
clockwise, plus any additional amount (1/8 turn
max.) to allow for lockwire installation. This pro-
vides the necessary built-in clearance adjustment
required for piston retraction after brake release.
6. Install lockwire ring (1).
7. Lubricate cylinder walls, threads, seals, piston
seal surfaces, etc. with clean C-3 hydraulic oil.
8. Install return pin washer (4, Figure 6-15) on pis-
ton assembly return pin (8) and install new return
pin O-ring (3).
9. Install dust shield (12) in groove of piston (11).
10. Refer to "Caliper Piston Installation".

BENCH TEST

The purpose of this test is to verify that overhaul of the
calipers was performed satisfactorily. If any leakage
occurs during this test the caliper assembly must be
rebuilt.
A hydraulic supply with sufficient volume and pressure
capacity to extend piston assemblies will be necessary.
A gauge of 0-2000 psi (0-14 MPa) should be placed in
the output line of the hydraulic source.
Fabricate two blocks using (front and rear) lining back-
ing plates as templates. Thickness of plate for the front
caliper should be 1.25 in. (31.75 mm) thick. Thickness
of plate for rear caliper should be 1.0 in. (25.4 mm)
thick.
1. If necessary, bolt caliper halves together with
mounting hardware or Grade 8 capscrews and
nuts of adequate diameter and length to securely
retain caliper halves together during testing.
Tighten capscrews and/or nuts to standard
torque.
2. Install new lining assemblies and appropriate test
block for caliper being tested.
3. Connect oil lines between two caliper halves.
Be sure test block is securely retained in caliper
head before applying pressure.
J06020