Component Tests and General Diagnostics

PARKING BRAKE: PARKING BRAKE ASSEMBLY: INSPECTION

INSPECTION

1. CHECK BRAKE DISC INSIDE DIAMETER





(a) Using a drum gauge or equivalent, measure the inside diameter of the disc.
Standard inside diameter:
240 mm (9.45 in.)
Maximum inside diameter:
241 mm (9.49 in.)
If the inside diameter of the disc is more than the maximum, replace the disc.
2. CHECK PARKING BRAKE SHOE LINING THICKNESS





(a) Using a ruler, measure the thickness of the shoe lining.
Standard thickness:
3.8 mm (0.148 in.)
Minimum thickness:
1.0 mm (0.0394 in.)
If the lining thickness is less than the minimum value, or if severe or uneven wear is present, replace the shoe.
3. CHECK BRAKE DISC AND PARKING BRAKE SHOE LINING FOR PROPER CONTACT





(a) Apply chalk to the inside surface of the disc. Rub the brake shoe lining against the disc and check that full contact is achieved between the brake shoe and disc (chalk is transferred to the entire brake shoe lining).
If the disc and brake shoe lining do not have full contact, grind the brake shoe using a brake shoe grinder or replace the brake shoe.
(b) After the inspection, wipe the chalk off of the inside surface of the disc and the lining surface.