4-86. BRAKE DRUM AND HUB REPLACEMENT/REPAIR (CONT).
Dry cleaning solvent P-D-680 is toxic and flammable. Wear protective goggles, face mask, and
gloves and use only in a well ventilated area. Avoid contact with skin, eyes, and clothes and
don't breathe vapor. Do not use near open flame or excessive heat. The flash point for type I dry
cleaning solvent is 100°F (38oC), and for type II is 140°F (60oC). If you become dizzy while using
cleaning solvent, get fresh air immediately and get medical aid. If contact with eyes is made,
flush eyes with water and get medical aid immediately.
DO NOT use a dry brush or compressed air to clean brake shoes. There may be asbestos dust
on brake shoes which can be dangerous to your health if you breath it. (Brake shoes must be
wet and a soft bristle brush must be used.)
Do not "spin dry" bearings with compressed air, the bearing may fly apart.
Clean all metal parts with dry cleaning solvent P-D-680 and dry.
Check bearings for pitting, rusting or wear.
Check races for grooves.
Brake shoes, drums and brake adjustment mechanisms must be cleaned of dirt, mud and debris
Measure edge thickness of brake lining. If brake lining is less than 1/8 in. (3.18 mm) at thinnest point,
replace brake shoes.
Inspect brake linings and drums for obvious grooves and uneven wear.
If brake linings are worn unevenly and less than 1/8 in. (3.18 mm), replace brake shoes.
If drum has deep grooves, replace drum.