Replacement Master Cylinder w/ Inline Solenoid for Demco Actuators - Drum Brakes

Video Transcript for Review of Demco Brake Actuator - DM5921

Today we're going to take a look at the replacement master cylinder with the inline solo Knight for Demco drum brake actuators. Now this is a replacement master cylinder. It's designed for use with the Demco trailer brake actuators with electric reverse lockouts. It is designed to work with the DA66B, the DA86, the DA91, the DA10, the DA16 and the DA20 models designed for drum brakes. You can see it has a nice composite master cylinder. It's very durable and efficient, has glass reinforced nylon construction to help resist rust and corrosion, and it's a very large reservoir provides increased capacity for your brake fluid.

Other nice features, if you look at the top here, has a standard automotive style diaphragm cap that'll help create completely enclosed system to help prevent contamination of your brake fluid. Now this master cylinder uses the electric first reverse lockout right here on the back, lets you back up without actuating your trailer brakes. Basically this master cylinder with this inline solenoid installs in your drum brake actuator and it wires to your tow vehicle so that the trailer brakes won't activate when you shift your vehicle into reverse. Has a ground wire and a power wire and see they're both yellow, so either one can be used for either function. The power wires connected to the reverse circuit`at happens is when the vehicles placed in reverse, electrical signal powers the solenoid which will prevent brake fluid from getting to the brakes.

Now this one is a non bypass configuration, which means when it's energized it'll just prevent the fluid from flowing anywhere. Also, one thing I do want to mention is the reason this master cylinders for only drum brakes is that it uses a residual valve in the cylinder that maintains approximately 10 pounds to 15 pounds of hydraulic pressure on your hydraulic circuit from the master cylinder out to your drum brakes wheel cylinders. And this reduces the time of brake activation by overcoming the pressure created by the drum brake return spring. So you do not want to use this cylinder for disc brakes because you do not need that residual valve in these brakes because that extra pressure created will partially activate your disc brakes during highway travel causing brake overheating and failure. Now if you do need the cylinder for disc brakes with the solenoid, we do sell that separately on our website.

It's part number DM5919. But that should do it for the review on the replacement master cylinder with the inline solenoid for the Demco drum brake actuators.