Video Transcript for Comprehensive Review: Demco Hydraulic Brake Actuator

Jeff: Hello everybody. This is Jeff at etrailer.com. Today, we're going to take a look at this Demco eight inch adjustable channel center hydraulic drum brake actuator. Has a 20,000 pound weight capacity. Now this hydraulic actuator will activate your trailer's brakes when your tow vehicle slows or stops. Basically what happens is when you apply the brakes in your tow vehicle, deceleration occurs and the momentum will push your trailer toward the rear of your vehicle.

So with the surge brake system, this actuator is triggered as your trailer moves forward once your tow vehicle starts to slow down. So when this happens, this inner slide portion of this actuator will actually contract back and it applies force to the master cylinder that's back here, and this in turn supplies the necessary hydraulic pressure to engage your trailer's brakes.What's nice is where this inner slide moves. It uses an acetal copolymer lining, which provides a nice smooth operation as the actuator telescopes in and out. If you notice on the front, it is an adjustable channel, has three different mounting positions for your coupler. Now, the coupler's not included.

That is sold separately on our website. This is a heavy duty steel construction. Has a nice prime finish to it. And in the very back here we mentioned that uses a composite master cylinder. It's very durable and efficient.

It's a glass reinforced nylon construction. That'll help resist rust and corrosion, and it offers a nice large reservoir which provides increased capacity for the brake fluid. The very top here you can see uses the automotive style diaphragm cap, which creates completely enclosed system to help prevent contamination of the brake fluid.If you notice, the breakaway cable right here is included. Now the breakaway cable is required by law, and what that's used for is it prevents a trailer runaway situation. What you'll do is take the end with the latched hook here, hook this to your tow vehicle, and then this cable runs to the lever right here.

And what happens is in the case of if your trailer would come disconnected from your tow vehicle, it'll pull this cable, which will activate the lever, which will apply pressure in the master cylinder to apply the brakes in a runaway situation. So it is required by law, but you don't have to worry. It is included.Now this is a weld on installation. It is made in the USA. Few specs on this, this is for trailers with hydraulic drum brakes. We mentioned the gross towing weight capacity is 20,000 pounds. Maximum tongue weight capacity is 2000 pounds. Now the channel width, right up front here, the inside width inside the inside is right at three inches. Overall channel height, bottom to the very top, is eight inches. It is designed to mount onto a three inch wide trailer tongue, and this also goes by the model number of DA20. Last note I do want to mention on this is because this actuator does not include a reverse lockout in the rear here, it is recommended that you either equip the trailer with a reverse lockout solenoid that screws in right here, or free backing brakes so that you can drive in reverse without the actuator triggering your trailer's brakes.But that's going to do it for the review on the Demco eight inch adjustable channel center hydraulic drum brake actuator, with the 20,000 pound weight capacity.