Drum Brake System: Testing and Inspection
BRAKE (REAR): REAR BRAKE: INSPECTION
1. INSPECT BRAKE CYLINDER AND PISTON
(a) Check the cylinder bore and piston for rust and scoring. If necessary, replace the brake cylinder assembly or piston.
2. INSPECT BRAKE DRUM INSIDE DIAMETER
(a) Using a brake drum gauge or an equivalent tool, measure the inside diameter of the drum.
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Standard inside diameter:
180.0 mm (7.09 in.)
Maximum inside diameter:
181.0 mm (7.13 in.)
If the inside diameter is more than the maximum, replace the drum.
3. INSPECT REAR BRAKE SHOE LINING THICKNESS
(a) Using a ruler, measure the thickness of the shoe lining.
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Standard thickness:
4.0 mm (0.157 in.)
Minimum thickness:
1.0 mm (0.0394 in.)
If the lining thickness is less than the minimum, or if there is severe or uneven wear, replace the brake shoe.
NOTICE:
Always replace both the right and left drum brake shoes together.
4. INSPECT BRAKE DRUM AND DRUM BRAKE SHOE LINING FOR PROPER CONTACT
(a) Apply chalk to the inside surface of the drum, and then grind down the brake shoe lining to fit the drum.
If the contact between the drum and the brake shoe lining is improper, repair it using a brake shoe grinder or replace the brake shoe.