Dexter Electric Over Hydraulic Actuator Will Not Build Pressure

Question:

Pmp wired correctly. No hydraulic leaks. Reservoir full. Pump 10 years old. Recent caliper replacements. Pump operates as designed but never builds up pressure. Disconnect line at and activate. Doesnt look like 1600 psi to me. Triple axle. No brakes whatsoever

asked by: Chris

Expert Reply:

I spoke to a Dexter engineer about the issue you are having with your actuator. They informed me that it could be one of two different things not allowing the pump to build pressure. These two things could be an issue with the control board or the proportioning valve.

The first thing you will want to check is the control board. The control board which sends voltage to the proportioning valve could be faulty. In order to test this you will need to pull the breakaway pin and see if you get any pressure. If you do then you know the control board is bad but if not then this points to signs of a bad proportioning valve.

The portioning valve is located deep inside the unit and will open and close based on the voltage it receives from the control board. If this valve is blocked or clogged then that could then prevent the valve from closing which means you would not have any pressure. Therefore, I recommend disassembling the unit and cleaning the screen that goes to the valve as well as inspecting it for any other foreign objects.

Unfortunately, the proportioning valve and control board are not offered as replacement parts for the actuator so if clearing the valve does not help your only option would be a full replacement for which I recommend using the Dexter DX Series Electric Over Hydraulic Brake Actuator part # K71-651 for disc or part # K71-650 for drum brakes.

expert reply by: Conner L