Troubleshooting EOH Horse Trailer Brakes That Stay Engaged When Brake Pedal is Released

Question:

we have a horse trailer that the hydraulic brakes wont release. with your foot off the pedal and the pump not running the brakes are locked up. it seems that the pressure is not returning to the pump. after a few minutes the brakes will then release. all lines leading to the brake assym. are steel. the rubber lines to the backing plate have all been replaced. new brakes on the entire unit. brakes have been bleed. the only part left to replace is the pump. would a bad pump cause the brakes to stay locked up?

asked by: Ben

Expert Reply:

Since you have replaced your brake assemblies and flexible brake lines, and have bled the system, the sticking brakes on your horse trailer are most likely caused by the electric-over-hydraulic actuator itself or its main steel brake line.

It is possible that the actuator is damaged and is not allowing the brake pressure to back off when you stop pressing the pedal. It is also possible that there could be a bit of foreign material in the main steel brake line (rust is most likely) that is preventing pressure from backing off immediately. A partial clog would certainly explain the brakes' behavior. If only one of the brake assemblies had this problem then the cause could possibly be localized to that one brake but since all brakes are staying engaged when you release the pedal it sounds like the actuator or the primary brake line coming from it is the problem. I suspect the brake line.

You can try disconnecting the main brake line from the actuator to see if there is any rust evident inside it. Chances are that it may just be easier to replace that main steel line and re-bleed the system. Since your actuator's pump works, and since the steel line is MUCH less costly to replace than the EOH actuator, I would try this first. We offer steel brake lines in various lengths, such as 19-foot # T4336000, 15-foot # T1086500, 10-foot # T1074500 and the 66-inch # T1086600.

In the event that you need to replace the actuator you can use the linked page to view all available items, such as the Cargo Towing Solutions HydraStar # HBA-10.