What is the purpose of a self adjuster in the drum brake system?
What is the purpose of a self adjuster in the drum brake system?
In a disc/drum application, the automatic adjusters play an important role in maintaining proper brake balance when the shoes are seating to the drum. The linings on premium replacement shoes are eccentrically ground to produce a clearance at the shoe’s heel and toe.
What is the importance of drum brake self adjusters?
The Importance of Drum Brake Self Adjusters. See more from Brake & Front End. Drum brakes have return springs to return the shoes to a rest position and hardware to hold the shoes to the backing plate. The shoes return to a fully retracted or rest position when the pressure to the wheel cylinder is released.
Where is the adjuster on a dual servo drum brake?
Dual Servo brakes use two primary shoes and two anchor pins. The pistons of the wheel cylinder apply both of the shoes. The adjuster is located under the wheel cylinder. The adjuster uses an adjusting screw and notched wheel and lever in the same way as the Bendix/Wagner unit. A lever is attached to one of the shoes to adjust the notched wheel.
How do you adjust the brakes on a drum?
You need to adjust the brakes manually first, then the self adjusters will keep them adjusted if all is working properly. When doing a drum job, I tear everything down. Use brake grease on the adjuster nut threads and the points of contact to the shoes.
When does the emergency brake adjuster come out?
When the brake shoes wear a little more, the adjuster can advance again, so it always keeps the shoes close to the drum. Some cars have an adjuster that is actuated when the emergency brake is applied. This type of adjuster can come out of adjustment if the emergency brake is not used for long periods of time.
When do you adjust the drum self adjusters?
Drum brake self adjusters should adjust when reversing and coming to a COMPLETE stop, no rolling then into forward. They only adjust one click each time this happens and if the rear brakes are already adjusted they will not tighten any farther.
Where is the adjuster located on a drum brake?
The lever is attached to the secondary shoe at the shoe hold down. A lever return spring is placed between the lever assembly and shoe. A spring connects the primary and secondary shoe to contain the adjuster.
When do you need to adjust drum brakes?
A modicum of self-adjustment has been built into drum brake systems, but the catch is that this self-adjuster only works when the car is being driven in reverse on some vehicles and only when the parking brake is engaged in others. As the car is moving in reverse and you step on the brakes, the shoes expand.
When the brake shoes wear a little more, the adjuster can advance again, so it always keeps the shoes close to the drum. Some cars have an adjuster that is actuated when the emergency brake is applied. This type of adjuster can come out of adjustment if the emergency brake is not used for long periods of time.
