Replacement Drum Brake Actuator for a Atwood 85778
Updated 05/15/2026 | Published 05/14/2026
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Question:
I have a 2000 boat trailer manufactured by Trailers by Dorsey, INC and the brake system on it is the Atwood system. I found the Part it tells me to refer to on top of the trailer - 85778 which brings me to a manual with the necessary information - I need to find a comparable replacement system for the trailer. Complete system everything for the brakes and I dont know exactly what to go with since I can no longer get the Atwood. What is recommended to replace with- with the least number of modifications needed to be made.
asked by: Ashley
Expert Reply:
Hey Ashley, thanks for the information! To replace a Atwood 85778 brake actuator, I recommend the Demco Hydraulic Brake Actuator item # DM62VR for drum brakes. It has the same 2" ball size and offers a bolt-on install for a 3" wide straight tongue.
Please note that the Demco Hydraulic Brake Actuator item # DM62VR has a manually lock out. If your boat trailer does not have free backing brakes, you can install the Reverse Lockout Solenoid Kit item # DM5836 which will automatically engage when you put the tow vehicle in reverse.
When you say complete system what exactly are you needing? If you need new lines, hubs, and brakes I'll need more some more information from you. Length of your trailer and how many axles for the lines. For brakes and hubs, I'll need to know the lug nut pattern of the wheels and the size of the spindle. There should be part numbers stamped inside on the inner and outer bearings that'll tell me what I need to know.
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Product Page this Question was Asked From
Demco Hydraulic Brake Actuator w/ Electric Lockout - Disc - Zinc - 2" Ball - 7,000 lbs
- Brake Actuator
- Surge Brake Actuator
- Farm Trailer
- Boat Trailer
- Construction Trailer
- Travel Trailer
- Utility Trailer
- Bolt-On
- 7000 lbs GTW
- 2 Inch Ball Coupler
- 3 Inch Channel Tongue
- Disc Brakes
- Electric Lockout
- Demco
more information >
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Big B.
5/15/2026
The actuator works very well. It did make me drill new mounting holes and that was the hardest part of the installation. All else was easy. I'm back to having a trailer I know will help me stop in a much shorter distance. Works very smooth no jerkiness. I'm very pleased.