Troubleshooting Surge Brakes Locking Up When Moving Forward

Published 03/01/2019

Question:

What causes surge brakes to drag and lock up going forward?

asked by: Robert M

Expert Reply:

Surge brakes use a hydraulic actuator to push fluid to the cylinder piston to activate the brake shoes on drum brakes or brake pads on disc brakes. This pressure should only be applied when weight is pushing against the hitch ball, so no pressure when moving forward and pulling the trailer.

With brakes dragging and locking up when going forward, there has to be something mechanically incorrect in the system like a sticking piston in the wheel cylinder keeping pressure on the brake shoes or a plunger in the master cylinder that is not releasing.

The most common issue when this happens is there is a shock like # T2336200 in the coupler to help the coupler return to position after compressing that has most likely failed. Depending on your coupler this may or may not be a replaceable part.

expert reply by: Jason S