Komatsu 830E-AC Shop Manual page 632

PERIODIC INSPECTIONS
Inspect the caliper, linings and disc on a periodic
schedule.
Shoes, Linings and End Plates
• End Plates. To help prevent abnormal lining
wear, replace worn, bent or cracked end plates
and distorted shoes. Inspect the end plate cap
screws for wear. Replace the cap screws if worn.
NOTE: End plate cap screws are highly stressed.
• Lining Wear. Replace the linings when the
thickness of the lining is less than 3.2 mm (0.125
in.) from the back plate.
• Lining Wear Not Even. Replace the linings if the
thickness of the two linings is significantly
different. Check the pistons for correct operation.
Replace the piston or housing if a piston is
cocked in the bore. Check that the disc surface is
flat and parallel to the linings.
• Oil or Grease on the Linings. Replace the linings.
• Cracks on the Linings. Replace the linings that
have larger or deeper cracks than the small, tight
cracks on the surface of the lining which are
normal when the caliper is used under high
temperature conditions.
referred to as heat check cracks.
J6-28
These cracks are
Armature Speed Rear Disc Brakes
Inspect the following areas for fluid leaks.
• Pistons. If fluid leaks at a piston, disassemble the
caliper. Inspect the piston, bore, O-rings and
backup rings. Service as necessary.
• Elbow Fitting. If fluid leaks at the elbow fitting,
tighten the fitting. If the leak continues, replace
the O-ring.
• Tube Assembly. If fluid leaks from the tube
assembly, tighten or replace the tube or fitting.
• Adjuster Pin. If fluid leaks at the adjuster pin, hold
the pin and tighten the nut to 120-150 lb-in (13.6-
17 N m). If the leak continues, replace the O-ring.
• Bleeder Screw. If fluid leaks at the bleeder screw,
tighten the bleeder screw. If the leak continues,
replace the bleeder screw.
• Inlet Fitting. If fluid leaks at the inlet fitting, tighten
the fitting. If the leak continues, replace the O-
ring.
Dust Boots
• Verify that the dust boots are soft and flexible.
• Disassemble the caliper and replace the dust
boots that are hard or damaged.
Brake Disc
• Refer to Brake Disc Inspection in this chapter. If
the disc is worn beyond the wear limits, replace
the disc.
10/06 J06025