Brake Drag
Brake drag is caused by the brake pads or shoes not releasing completely when the brake pedal is released. The vehicle will pull to one side, this will be especially noticeable if it involves one of the front brakes. There are different reasons this can occur depending on the type of system. This problem must be diagnosed and repaired immediately. It will result in overheated parts and possible damage to the braking system.
Possible causes include:
1. Master Cylinder
a. Brake drag can be caused by the brake pedal adjustment. This pedal adjustment is crucial because when adjusted to tightly the compensation and vent port of the master cylinder can become blocked building pressure in the system resulting in brake drag and possible brake lockup. A slight gap should be present between the push rod and the master cylinder.
b. A worn or corroded master cylinder bore can cause excesses pedal effort and result in dragging brakes.
2. Brake Lines/Hoses
a. There may be pressure trapped in the brake line. This happens when the brake line is pinched or kinked and pressure is high enough while applying the brakes to bypass the kink, but when the pedal is released the spring pressure of the master cylinder is not sufficient to bypass the kink leaving the brakes still applied resulting in brake drag.
3. Poor Lubrication
a. The sliding and moving parts of the brake system require lubrication to prevent them from binding. Lubricate slide pins on disc brakes to prevent brake drag and binding. *Lubricate the pads where the brake shoes ride on the backing plate of drum brakes. This will help prevent a possible squeaky noise as the shoes move across the plate.
4. Return Springs
a. Weak or broken return springs will result in brake drag. This happens with drum brake systems as the return springs wear or become rusty due to exposure to water and the environment.
