Caution: Avoid taking the following actions when you service wheel brake parts:
• Do not grind brake linings. • Do not sand brake linings. • Do not clean wheel brake parts with a dry brush or with compressed air.
This drum brake assembly is a leading/trailing shoe design. Both brake shoes are held against the wheel cylinder pistons by the lower return spring and the fixed anchor plate near the lower return spring. When the brakes are applied, the wheel cylinder pistons move both shoes out to contact the drum. With forward wheel rotation, the forward brake shoe will wrap into the drum and become self-energized. With reverse wheel rotation, brake shoes is transferred to the anchor plate through the braking plate to the axle flange. Adjustment is automatic and occurs on any service brake application. Do not switch the position of shoes that have been in service, as this may render the self-adjustment feature inoperative and result in increased pedal travel.
Important:
• Replace all the components included in the repair kits used to service
this drum brake. • Do not use lubricated shop air on the brake parts, as damage to the rubber
components may result. • If any hydraulic component is removed or disconnected, it may be necessary
to bleed all or part of the braking system. • Replace the shoe and linings in axle sets only. • The torque values specified are for dry, unlubricated fasteners. • Perform service operations on a clean bench that is free from all mineral
oil materials.
