Comparing Bypass and Non-Bypass Electric Reverse Lockout Solenoids for Surge Couplers

Updated 03/15/2016 | Published 03/12/2016

Question:

What is the difference between a bypass actuator and a non bypass actuator?And can I buy it already installed?

asked by: Gary

Expert Reply:

Demco Solenoid Kit (Bypass) # DM5404, when energized, will only allow the brake fluid to flow back into the master cylinder. A non-bypass, when energized, will just prevent the fluid from flowing anywhere.

The type used depends on the master cylinder type on the actuator. To use a bypass type the master cylinder has to have a return port for the fluid to flow back into. A master cylinder without this feature would use a non-bypass.

Both thread into the back of the master cylinder directly. One wire will ground to the trailer frame and the other wires into the reverse light circuit on the trailer connector. You can get actuators that already have an electric reverse lockout installed so you won't have to retrofit one onto an actuator. I have included a link to them for you.

If you can tell me the capacity you need and if you have disc or drum brakes on the trailer I can make a specific recommendation.

expert reply by: Michael H