How to Diagnose Dragging Brakes

Pinpointing brake problems stump many car owners. Questions arise about whether or not the trouble plagues the front or back wheels. Diagnose dragging brakes by checking the drums after first isolating the problem to the back wheels. In addition, think "safety-first" with any car repair or diagnosis. Use caution, wear the proper safety gear and work with a friend when possible.

Instructions

1

Determine if the dragging occurs in the front or back wheels. Lift up the front and back ends of the car separately to see if the wheels turn freely. If the wheels stick on the back end, then the brake drums may be causing the problem. Jammed wheels on the front end of the car could result from brake disc issues. Use a car jack to hoist up the vehicle.

2

Find out what part of the drum brakes is causing the dragging. Pinpoint the problem by looking at the parking brake cable, the brake adjusters and the wheel cylinders.

3

Check the parking brake cable. Inspect the area for rust, which can jam the cable in its holding area. Releasing a parking break lever will not free a rusted cable from its housing, and that results in dragging. Wheels turn slower than usual because the cable pulls one of the shoes against the drum.

4

Examine the brake adjusters. Use a plastic faced hammer to separate the drums from the shoes. Brake adjusters automatically place the shoes near the drum as the shoes' friction material wears out. If the adjuster pushes the shoes out too far, they will drag against the drum.

5

Inspect the wheel cylinders. If these are stuck, they produce symptoms similar to jammed brake adjusters. Corrosion forms inside the system due to lack of brake fluid that causes the wheel cylinders to stick in the open position. This results in brake shoes pressing on the drum even after releasing the brakes.