Replacement Master Cylinder for Atwood 85778 Actuator
Updated 02/17/2026 | Published 06/14/2024
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Question:
Is a master cylinder brake kit available for a Atwood 85778
asked by: Brian S
Expert Reply:
No, I am sorry Brian we do not. Your Atwood 85778 uses the master cylinder 85841, which is no longer available. Atwood doesn't produce any actuator components anymore so it's getting harder and harder to track down replacement parts. Hopefully this part number helps you track one down.
If it does not, you can replace the Atwood 85778 actuator with the Demco item # DM72VR for drum brakes or item # DM62VR for disc brakes. These each have a 7,000 lbs towing capacity, a trigger-style latch that's easy to use for a secure connection, and are made in the USA. They work with 3" wide trailer tongues.
Product Page this Question was Asked From
Demco Hydraulic Brake Actuator - Drum - 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
- Drum Brakes
- No Lockout
- Demco
more information >
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Jerred H.
2/17/2026
Hey Brian, did you end up replacing your Atwood 85778 actuator with one of the Demco options? Knowing which route worked could really help others trying to find parts for older Atwood setups.