Brake Adjustment And Lining Tolerances; Removal And Disassembly Of Wheel Brake Assembly; Cleaning, Inspection And Repair Of Wheel Brake Assembly - Piper Navajo PA-31 Service Manual

PIPER NAVAJO SERVICE MANUAL
7-49. BRAKE ADJUSTMENT AND LINING TOLERANCES. No adjustment of the brake clearance
is
necessary as they are self-adjusting. Inspection of the lining is necessary and it may be inspected visually
while installed on the airplane. The linings are of the bonded type and need not be replaced until the
thickness of any one segment becomes worn to .100 of an inch or unevenly worn.
7-50. REMOVAL AND DISASSEMBLY OF WHEEL BRAKE ASSEMBLY. (Refer to Figure 7-16 or
7-16b.)
a. To remove the brake assembly, first disconnect the brake line from the brake cylinder housing (15).
Cap brake line to prevent contamination.
b. Remove the self-locking cap bolts (1) that secure the backing plates (10) and shim (8) or (9) to the
brake cylinder housing (15).
c. Slide the brake cylinder housing from the torque plate.
d. Remove the pressure plate (6) by sliding off the anchor bolts of the housing.
e.
The pistons may be removed by injecting low air pressure in the cylinder fluid inlet and forcing the
pistons from the housing.
f. The following procedure should be used when removing anchor bolts:
1.
Position cylinder assembly on a holding fixture. (Refer to Figure 7-16a, Step A.)
2. Use a suitable arbor press and remove the anchor bolt from the cylinder body.
g. Lining may be removed from a backing plate by inserting a sharp tool between the lining and
plate. Press new lining on the backing plate.
7-51. CLEANING, INSPECTION AND REPAIR OF WHEEL BRAKE ASSEMBLY.
a. Clean the assembly with dentured alcohol and dry thoroughly.
b. Inspect "O" rings for cuts, nicks, distortion or excessive wear. If necessary replace with "O" rings
of corresponding part numbers.
c. Inspect brake cylinder(s) for cracks, especially in the lug area around the anchor bolts. Cracked
cylinder should be replaced.
d.
Inspect pressure plate and back plates for cracks or warpage. Replace if cracked or severly
deformed.
e. Inspect inlet and outlet hydraulic parts for contamination. Light scratches or nicks in the piston
bores, pilot bores or on the chamferred surfaces within these bores may be polished out with 600 grit
emery cloth. Thoroughly clean out any residue.
f. Inspect anchor bolt holes in torque plate for internal corrosion or contamination. If present clean
with emery cloth and apply a light coat of dry lube.
g. Inspect bolts for cracks, thread damage or corrosion and replace if necessary.
h.
Inspect pistons for nicks or burrs.
Remove nicks or burrs by polishing with 600 grit emery
cloth. Thoroughly clean before installing.
i.
Inspect brake linings for edge chipping and surface deterioration. Refer to Figure 7-16 or 7-16b
for maximum wear limits for brake linings and discs. Discs warpage should not exceed .015 or.010 inch.
j. Paint exposed areas with one coat zinc primer and one coat of aluminum lacquar.
Reissued: 10/12/79
LANDING GEAR AND BRAKE SYSTEM
2G6