Park Brake Caliper Disassembly; Cleaning And Inspection - Komatsu 830E Shop Manual

Park Brake Caliper Disassembly

NOTE: To assure that tension on springs (9, Figure
7-2) has been released, be certain that jam nut (17)
has been loosened on adjustment bolt (16) and that
clamping capscrew (3) has been loosened one turn.
Be sure that adjustment bolt (16) has been loosened
six turns.
1. Remove bleeder screws (11, Figure 7-2) from
housing (2) and drain fluid from brake caliper.
2. Loosen jam nut (17) and remove adjustment
bolt (16) from yoke (1).
3. Remove clamp capscrew (3) and washer (4) to
release housing (2) from yoke (1).
4. Remove piston dust boots (8) from spring
retainers (15).
5. Remove spring retainers (15) and springs (9).
Note order and orientation of springs.
6. Remove pistons (10) from housing.
7. Remove seal and backup ring (6 & 7) from pis-
tons and discard these parts.
8. Remove screws (14) releasing the lining (5)
from pistons.
9. Remove seal and backup ring (6 & 7) from
housing and discard these parts.
J7-4

Cleaning and Inspection

Petroleum base cleaning solvents are flammable.
DO NOT USE NEAR OPEN FLAME.
1. Clean all metal parts of brake assembly in
cleaning solvent.
2. Inspect all metal parts for breaks or cracks.
Replace all cracked parts.
3. Measure pistons and housing bores. Replace
the parts if they are worn beyond the following
limits:
Piston:
• Large O.D. . . . . . . . . . . . . 4.494 in. (114.1 mm)
• Small O.D. . . . . . . . . . . . . . .2.493 in. (63.3 mm)
• Seal groove . . . . . . . . . . . .4.126 in. (104.8 mm)
Housing Bore:
• Large I.D. . . . . . . . . . . . . . . 4.503 in. (114.4 mm)
• Small I.D. . . . . . . . . . . . . . . 2.504 in. (63.6 mm)
• Seal groove. . . . . . . . . . . . . 2.869 in. (73.6 mm)
4. Inspect inlet and bleeder holes in housing (2)
for thread damage. If re-threading is necessary,
use the following taps:
• Lining bolt hole in piston . . . . 10-24 UNC-2B tap
• Inlet hole . . . . . . . . . . . . . . . 7/16-20 UNF-2B tap
• Bleeder hole . . . . . . . . . . . . . 1/4-28 UNF-2B tap
After tapping, be certain all metal chips and resi-
due are removed from openings and hydraulic
passages. If threads are not serviceable, replace
housing.
Rockwell Parking Brake J07013