Leading/Trailing

Leading/trailing drum brakes are used on vehicles up to and including a 6450 pound GVW rating (excluding the Police Package). Both brake shoes are held against the wheel cylinder pistons by the upper return spring and against the fixed anchor plate by 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 wraps into the drum and becomes self-energized.

With reverse wheel rotation, the rear brake shoe is self-energized. Force from the brake shoes is transferred to the anchor plate, through the backing plate, and finally to the axle flange. Adjustment is automatic and occurs on any brake application. It is normal for the front (leading) shoe and lining assembly to wear faster than the rear (trailing) shoe and lining assembly.