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Review of Demco Brake Actuator - Surge Brake Actuator - DM8759122-30

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Demco Brake Actuator - Surge Brake Actuator - DM8759122-30 Review


Hello everybody, this is Jeff at etrailer.com. Today, we're gonna take a look at the Demco eight inch Adjustable Center Channel Hydraulic Drum Brake Actuator, has an 8,000 pound gross towing weight capacity. 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 towards the rear of your tow vehicle. So with the surge brake system, the actuator is triggered as your trailer moves forward once the tow vehicle starts to slow down. So when this happens, the inner portion of the actuator right here will contract and apply force to the master cylinder at the back here, and then this in turn supplies the necessary hydraulic pressure to engage your trailer's brakes.

This one here happens to use an acetal copolymer lining around the actuator inner portion that goes into the outer portion, this will provide a nice smooth operation as the actuator telescopes in and out. This one has have an adjustable center channel, has three different mounting positions for your coupler. Now, the coupler's not included, that would be sold separately. This does have a nice black powder coat finish to it to resist rust and corrosion. It is a heavy-duty steel construction.

On the very back here, they do use a composite master cylinder, which is durable and efficient. It's a glass-reinforced nylon construction that'll resist rust and corrosion, has a very large reservoir, which provides increased capacity for your brake fluid, and if you noticed on the top here, the cap that you'll open to put the brake fluid in, uses an automotive-style diaphragm cap, which will create completely enclosed system, helps prevent contamination to brake fluid. This does include the breakaway cable and a hook that is required by law, and what this does is prevent a trailer runaway situation. Basically, what you'll do is when you hook your trailer up to your tow vehicle, you do wanna take this hook, hook it to your tow vehicle, so in case this happens to come detached from your tow vehicle, this cable will pull on this lever, which the lever will activate the master cylinder to apply pressure to the brakes, prevents a runaway situation. Now, this is a bolt-on or weld-on installation.

Go ahead and put the this back here, there we go. It is a bolt-on or weld-on installation, it does mount to a straight three inch wide trailer tongue. This part is made in the USA. Application on this is for trailers with hydraulic drum brakes. We mentioned the gross towing weight capacity is 8,000 pounds, maximum tongue weight capacity, 800 pounds.

Now, the channel up front here, the width of it, which will measure the inside, is gonna be right at three inches. The overall height of it, bottom to the top is right at eight inches tall. Now, this part also goes by a model number DA91. One last note I do wanna mention on this actuator is because this does not include a reverse lockout, it is recommended that you equip your trailer with either a reverse lockout solenoid that installs in the back here, or to have free backing brakes on your trailer, so that you can drive in reverse without the actuator triggering your trailer's brakes. But that should do it for the review on this Demco eight inch Adjustable Center Channel Hydraulic Drum Brake Actuator with the 8,000 pound gross towing weight capacity..


Info for this part was:

Employee Jeff D
Installed by:
Jeff D

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