Inspection Of Brake Assembly; Cleaning Of Brake Assembly - Piper Cheyenne IIIA Airplane Maintenance Manual

PIPER AIRCRAFT
PA-42-720 (Advanced Trainer)
MAINTENANCE MANUAL
B. Brake Assemblies (continued)
5. Inspection of Brake Assembly
(a) Inspect O-rings for nicks, distortion, or excessive wear. Replace as necessary.
6. Cleaning of Brake Assembly
(a) Except for disc-carriers and lining assemblies, clean all metal parts with a Stoddard solvent or
suitable equivalent.
(b) Remove and clean O-rings with denatured alcohol; dry thoroughly.
(c) If the finish on torque plate or housing assembly needs refinishing or removal, use the following
instructions to remove old paint from metal surfaces.
NOTE: It is not necessary to strip paint on assembly to inspect using dye-check or fluorescent
penetrant.
7. BrakeWear Limits (referto32-40-00 Chart 3)
BREAK WEAR LIMITS
CHART 3
Disk Carrier and
Carler, Lining and
Inspection Areas Linign Assembly
Torque Button Assys
Thickness Max. 0.519
0.265
Min. *0.370
*0.160
Dishing Max.
0.050 +0.025
(Flatness)
Min. 0.000
0.000
I.D.
Max. 7.000 7.000
Min.
6.800 6.800
*Minimum thickness is 85 percent of lining surface. This is an overhaul limit only.
Parts may wear beyond these dimensions in service.
+Carrier, lining, and torque button assemblies can be cold flattened with a mallet and
flat plate. Check flatness on lining side of segment.
In order to prevent premature removal and subsequent overhaul of brakes still serviceable, B. F.
Goodrich has established a brake removal wear limit (BFG S/B 399) check procedure. Proceed as
follows:
(a) Pressurize brake to 100 psi.
(b) Measure distance between the carrier. Line and torque button assembly and the piston
housing (refer to 32-40-00 Figure 404). (A 0.350 inch measurement indicates brake needs to
be overhauled.)
EFFECTIVITY:
040-999
PAGE 16
Jan
10/9032-40-00