6-67. BRAKE DRUMS
This task covers:
Tool Kit, General Mechanics, Automotive
Brake Drums Removed (see para 5-37.)
Dry cleaning solvent P-D-680 is
repeated and prolonged breathing
of vapors and skin contact with the
Do not use near open
flame, arcing equipment or other
ignition sources. Always wear eye
protection and protective clothing.
The flash point of P-D-680 is 100
to 138 deg. F (38 to 59 deg. C).
(1) Clean brake drum with dry cleaning solvent (Item 3,
(2) Check brake drum for wear, cracks or damage. Replace brake drum if damaged beyond repair.
Slight scoring conditions can be corrected by polishing with
crocus cloth (Item 34, Appendix E). Heavy scoring and out-of-
round conditions require turning brake drum on a refinishing
Whenever the drum on one side of the axle is refinished, the
other drum on the same axle must be turned to the same size.
(3) Check inner brake surface of drum for heat checking, scoring or warpage.
(4) Using micrometer, check inside of brake drum for out-of-round or tapered wear.
(5) Record each reading. The maximum difference between the four readings cannot exceed 0.006
inch (0.1524 mm). Drums with out-of-round exceeding limits must be turned.