Demco Hydraulic Brake Actuator - Drum - Zinc - 12" Adjustable Channel Center - 20,000 lbs

Video Transcript for Review of Demco Brake Actuator - Surge Brake Actuator - DM8202521

Jeff: Hello, everybody. This is Jeff at etrailer.com. Today, we're going to take a look at this Demco 12-inch Adjustable Channel Center Hydraulic Drum Brake Actuator with 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, the deceleration occurs and the momentum will push your trailer toward the rear of your vehicle. So with the surge brake system, this actuator is then triggered as your trailer moves forward once the tow vehicle starts to slow down.

And when this happens is the inner portion of this actuator will actually slide back or contract and applies force to the master cylinder in the back here and this in turn supplies the necessary hydraulic pressure to engage your trailer's brakes. Now, this actuator uses a nice acetyl copolymer lining around the inner slide. It provides a nice smooth operation as the actuator will telescope in and out.This one is an adjustable channel. It has five different mounting positions for your coupler. Now the coupler is not included, we do sell that separately.

This does have a nice zinc plating on it, gives you excellent corrosion resistance. Has a 500 hour salt spray rating, so it is great for marine applications. It is a heavy duty steel construction. Now in the back here, we mentioned the master cylinder, which is underneath there in the very rear. It's a composite master cylinder.

It's very durable and efficient. It's a glass reinforced nylon construction, helps resist rust and corrosion, and it's a nice large reservoir, so it provides increased capacity for the brake fluid. If you notice on the top here where you put your brake fluid in, it's an automotive style diaphragm cap, which will create a completely enclosed system, help prevent contamination of the brake fluid. Now, this does include this breakaway cable and hook with the latch on it.You can see here's your hook with the latch, and then here's your cable. Now this is required by law because it prevents a trailer runaway situation.

So basically what you'll do is take this hook and the latch, hook this to your tow vehicle and then what'll happen is by chance, if your trailer gets disconnected from your tow vehicle, it'll stretch this cable, which will activate the lever and that lever applies the pressure of the master cylinder back here, which again, will apply the brakes on the trailer to prevent a runaway situation. So it is a safety feature that is required by law and it will be included with this actuator.Now this is a bolt on installation. You can see the holes right here at the bottom for installing it. It is designed to mount onto a straight three inch wide trailer tongue. This actuator is made in the USA. This is for trailers with hydraulic drum brakes. Gross towing weight capacity is 20,000 pounds. Maximum tongue weight capacity is 2000 pounds. Now the channel width, which is measured inside to inside, it's going to be approximately about three inches. Channel height, bottom to the very top, let's do it this way, is right at 12 inches. This does go by the model number of DA20. And one last note I do want to mention on this actuator is because this actuator does not include a reverse lockout back here on the master cylinder, it is recommended that you hook the trailer with a reverse lockout solenoid that will screw onto the master cylinder back here or free backing brakes on your trailer so that you can drive in reverse without this actuator triggering your trailer's brakes.But that should do it for the review on the Demco 12-inch Adjustable Channel Center Hydraulic Drum Brake Actuator with a 20,000 pound weight capacity.