Video Transcript for Comprehensive Review: Demco Hydraulic Brake Actuator-DM8101021

Hello everybody, this is Jeff at etrailer.com. Today we're gonna take a look at this Demco eight inch adjustable center channel hydraulic drum brake actuator. Has a 12,500 gross towing weight capacity and a zinc plate finished to it. Now this hydraulic actuator will activate your trailer 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. With a surge brake system like this, the actuator is then triggered as your trailer moves forward, once the tow vehicle starts to slow down and when this happens, this inner slide portion of the actuator will contract, applies force to the master cylinder in the back here, and then this in turn supplies the necessary hydraulic pressure to engage your trailer brakes and stop the trailer.

This does use acetal copolymer linings between the inner slide tube and the outer case. These will provide a nice smooth operation as this actuator telescopes in and out. We mentioned this adjustable channel, has three different mounting positions for your coupler. Now the coupler's not included. We do sell that separately on our website.

Give you an idea of the dimensions on this channel, the overall height of it, bottom to top is right at 8 inches. The width, which would be measured inside to inside it's right at 3 inches wide. Now this is a heavy duty steel construction. You can see it does have a nice zinc plating on it, gives you excellent corrosion resistance. Has a 500 hour salt spray rating so this is great for marine applications.

Now, the master cylinder we mentioned it's in the back here, this is a composite master cylinder. It's very durable and efficient. It's a glass-reinforced nylon construction to resist rust and corrosion, and it gives you a large reservoir, which provides increased capacity for the brake fluid. Up at the top here, you can see has this automotive-style diaphragm cap, which creates a completely enclosed system to help prevent contamination of the brake fluid. Now on top here, you notice they have this breakaway cable and the hook that's included in this, and this is required by law.

And the reason is, this will prevent a trailer runaway situation. Basically what happens is when you hook up your trailer to your tow vehicle, you'll take this hook with the keeper on it and extend that cable to your tow vehicle and hook it onto it, and then what happens in the case if this comes detached from your tow vehicle it will pull this cable, which will activate the handle here. This lever'll move forward, which again, will activate the hydraulic pressure in your brakes, or your master cylinder here, which will then apply the brakes to prevent a runaway situation. And again, this is all included. Now, this is a bolt-on installation. You can see at the very bottom here, this'll bolt onto a straight three-inch-wide trailer tongue. This part is made in the U.S.A. Application, again, this is for trailers with hydraulic drum brakes. Gross towing weight capacity on this is 12,500 pounds. Maximum tongue weight is 1,250 pounds. This does go by the model number of DA10. One last note I do wanna mention on this actuator is because this actuator does not include a reverse lockout, it is recommended that you equip your trailer with either a reverse lockout solenoid that will unscrew right into the back of this master cylinder or that your trailer has free-backing brakes 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 eight inch adjustable center channel hydraulic drum brake actuator, 12,500 pound gross towing weight capacity, and a zinc plate finish.