How Do I Convert A Blocking Type Surge Brake Solenoid To A Bypass Type Solenoid

Question:

Our Four Winns Boat trailer has a Tiedown surge brake coupler actuator. Tiedown uses a blocking type solenoid with only a hot wire and uses the trailer frame as the ground, this is giving us intermittent problems backing up even slight grades. We have to put a pin in the lockout hole which is a pain when backing in the driveway from the street because there always somebody pulling up while your crosswise in the street wanting to get by you. The trailer shop thought it was an intermittent ground problem with the swing away tongue but after researching Tiedown actuators and Four Winns boat trailers. I have decided it is more likely the Tiedown decision to use this type actuator because from what I have read if there is pressure in the brake system even though the solenoid is working a blocking style solenoid wont release the pressure. Some people suggest releasing the brake just before going into reverse but I feel this will be rough on the transmission. Is there a kit that I can convert from a blocking to a bypass solenoid. Second option would be swapping the whole actuator. Are surge brake actuators interchangeable with other companies couplers or do I have to get the whole actuator/coupler unit? I would like to fix this as inexpensively as possible.

asked by: David S

Expert Reply:

In theory, we do have a solution that would turn your blocking solenoid into a bypass solenoid. The Demco Solenoid Kit for Brake Actuators with Reverse Lockouts - Bypass, part # DM5404, is designed just for this reason, to keep your trailer brakes from activating when you shift into reverse. Unfortunately, we cannot guarantee that it will work for your application. If that does not work, there is a slight chance you could swap out the master cylinder, but they are usually fit guided or at least more fit specific than just the solenoid. If this solution does not work and it is the solenoid itself that is causing the issue, correcting the problem will require a new actuator. We are available to help you find an actuator that has the bypass solenoid, if needed, in order to avoid this problem again.

I have included a product description and a video demo of the Demco Solenoid Kit below.

expert reply by: Mark Smith