Important:
This drum brake is an advanced leading/trailing shoe design. The advanced design operates with less total parts. The drum brake performance is equivalent to other drum brakes while providing improved reliability. The operation and servicing of the advanced design brake is much simpler than traditional drum brakes.
This brake system employs a single universal spring (4). The single universal spring holds both the shoe and the lining assemblies (11, 5) to the backing plate (10). The spring also acts as the return spring for both the shoe and the lining assemblies. Force from the brake shoes transfers through the fixed anchor and backing plate to the axle flange. Adjustment is automatic and occurs on any service brake application. Also, with leading/trailing brakes, it is normal for the leading (front) shoe to wear at a faster rate than the trailing (rear) shoe.Do not switch the position of shoes that have been in service. Switching shoes may render the self adjustment feature inoperative and result in increased pedal travel.
Servicing the front brakes will usually correct pulsation in the brake pedal. Service the rear brakes only if the problem persists.
Thoroughly clean and inspect the brake drums for the following condition when the drums are removed for service:
• | Cracks |
• | Scores |
• | Deep grooves out-of-round |
• | Taper |
Normal, light scoring of the brake drum surfaces not exceeding 0.51 mm (0.020 in) in depth will not affect brake operation.