Troubleshooting Trailer Hydraulic Brakes Locking Up

Question:

We were going camping. Were going up a small incline when the wheels locked up. Finally released so we could move to a safe area. We had this happen one other time just momentarily then could move. We are afraid to take it anywhere. My husband cut the brake line and we were able to get it back homejust a few miles from home. What could be the problem. We purchased the trailer new 12 years ago and only camp about 3 times a year. Please help us.

asked by: Marilyn P

Expert Reply:

It sounds like your husband had to cut a hydraulic brake line to free-up your trailer's locked brakes. Causes for this kind of issue could be anything from a bad master cylinder in your actuator/coupler, to a blockage in one of the brake lines, to damaged/rusted brake assemblies, or to the brake fluid deteriorating. A 12-year-old trailer, even if used gently and stored properly in the off-season, could have by now developed any of the above problems.

Trailer brakes should be bled and their fluid changed every single year. For reference, this and other routine trailer maintenance is outlined in the linked article.

At the very least you'll need to flush and replace the brake fluid and the brake line that was cut. I have linked our main page for brake line kits which are available in both steel and flexible types. We also offer individual steel lines like # T1086600 and also complete brake line kits like # DM5426.

I suggest you inspect the entire system from coupler to brakes, looking for any obvious damage (such as a crimp in the line caused by a hit from road debris) and then replace the brake line that was cut and replace the brake fluid. This process has to be done anyway and it will be the least costly way to see if a clog or deteriorated brake fluid was the cause of the issue.

I have also linked our main pages for actuator/couplers and hydraulic drum brake assemblies.

expert reply by: Adam R