Troubleshooting Dexter Electric Over Hydraulic Actuator that Won't Work Consistently
Updated 04/29/2026 | Published 04/27/2026
Question:
I have a 2021 Alliance Paradigm 385FL with the Dexter DX Series Electric Over Hydraulic Brake Actuator for Disc Brakes - 1,600 psi Part Number: K71-651. Im towing with a 2024 GMC Sierra 3500. I have added your Adapter Module for BrakeRite Electric Over Hydraulic Actuator - OE Ford, GM Brake Controllers ITEM DX35FR. Several weeks ago when preparing to leave a campground, the trailer brakes would not work. I checked all the connections and it appeared the brake fluid was low. However, the brakes started working again and I had no problems on the 2 hour drive home. Once home, I followed the Dexter manual for that unit, I disconnected the blue, black, and yellow wires. Touching the yellow wire to the positive terminal on the battery activates the pump. Touching the black wire to the positive terminal does not activate the pump. Touching the blue and black wires together to the positive terminal does activate the pump. This is correct according to Dexter. I reconnected everything thinking it was okay. However, this past weekend we went to a campground an hour away and did not have trailer brakes. While at the campground I pulled the emergency cable and the pump would not activate. I again followed the test procedure and the pump activates as it should. I did it again immediately before leaving for home, and the brakes worked fine all the way home yesterday. Today, I pulled the emergency cable and the pump would not activate. I again ran the test procedure on the three wires and the pump activates as it should. I reconnected all the wires and pulled the emergency cable and the pump activates properly. The bottom line of all this is if the unit sits for any length of time, the pump doesnt seem to activate. However, if I follow the Dexter test procedure and connect the wires directly to the battery the pump works properly. I really dont want to $1,000 on a replacement pump unless I know that is truly the problem frankly a brake component shouldnt fail in 5 years. I would appreciate any thoughts or suggestions you might have for additional testing.
asked by: ROBERT K
Expert Reply:
Hey Robert, this sounds like an issue we see somewhat often with the OEM brake controller of your truck. OEM brake controllers even when using the adapters just don't love to be used with electric over hydraulic actuators consistently. Is there anyone you know with a truck with an aftermarket controller that you could test with? If you can get the problem to happen again with an aftermarket brake controller that has a hydraulic mode I would say it sounds like the actuator. If the problem won't happen then it would be time for a new controller.
Steven
4/29/2026
I replaced my actuator/master cylinder on my gooseneck with the new Dexter unit. 2019 Ford F350. It use to work just fine but couldn’t get it to work with the new controller. I ended up putting a Tekonsha controller in, wiring it separately, splitting the positive and negative wires out of the trailer loom and it works just fine. Dexter is really no help, Ford, GM, Dodge no help. I think the problem is in the factory controllers but no one seems to know what the problem is. Hydraulic brakes are the best, that’s why all vehicles have them. But integrating them with the newer trucks can be next to impossible. Dexter and the vehicle manufacturers agree there is a problem but no one seems to know what it is. Very frustrating. It’s really just two wires, just how hard can it be. In the St Louis area trailer dealers don’t order trailers with EOH brakes because they know operation is iffy. But no one seems to be able to say “here’s the fix”. Good luck.
Jameson C.
4/29/2026
Product Page this Question was Asked From
Dexter DX Series Electric Over Hydraulic Brake Actuator for Disc Brakes - 1,600 psi
- Brake Actuator
- Electric-Hydraulic Brake Actuator
- Boat Trailer
- Travel Trailer
- Disc Brakes
- Dexter
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Rob K.
4/27/2026
I understand what you're saying, but it's odd that it would work fine for 2+ years. Also, that wouldn't explain why pulling the emergency cable doesn't trigger the pump unless it's immediately after running the test procedure.