This actuator is built with heavy-duty steel and rated for 20,000 lbs gross towing weight and 2,000 lbs maximum tongue weight. It’s made for serious hauling—construction rigs, farm trailers, or big equipment setups that need confident braking power. The surge-style design automatically activates your trailer’s hydraulic drum brakes when you slow down, so stopping stays smooth and consistent without any extra setup or wiring.
The primed finish gives you a clean surface ready for paint or extra coating before installation. Inside, a glass-reinforced nylon master cylinder resists rust and corrosion that can eat away at steel or aluminum. The large reservoir holds more brake fluid for fewer refills, while the automotive-style diaphragm cap keeps moisture and dust out of the system to help prevent contamination over time.
The telescoping mechanism uses an acetal copolymer lining that keeps things moving smoothly each time the actuator compresses and releases. That means consistent braking response without sticking or jerking as you tow up hills or through stop-and-go traffic.
The built-in 8" adjustable channel gives you three mounting positions to match your coupler height. The channel-down configuration adds more drop, which helps line up taller trailers so they sit level when hitched. You can mount different coupler types (sold separately)—a standard ball coupler, lunette ring, or clevis—using the same setup without extra adapters.
If the trailer ever disconnects, the integrated breakaway lever pulls automatically to engage the brakes. A snap hook on the safety cable provides a solid connection so the system reacts right away if separation occurs. It’s a simple mechanical safeguard that helps keep your trailer under control in an emergency.
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Hello, everybody, this is Jeff at etrailer.com. Today, I'm gonna take a look at this Demco eight-inch adjustable channel down hydraulic drum brake actuator with a 20,000 pound gross towing weight capacity and a primed finish. 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, and, with surge brake systems, this actuator is then triggered as your trailer moves forward once your tow vehicle starts to slow down. Now, when this happens, the inner slide of this actuator will 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 and stop the trailer. Now, this one here uses an acetal copolymer lining between this inner slide tube and the outer case, provides a nice smooth operation as the actuator will telescope in and out.
Now, this one is an adjustable channel, has three different mounting positions for your coupler. Now, the coupler is not included, we do sell those separately on our website. And, if you notice on this one, it's a channel down design, and what that allows for is a lot greater drop, so it works good on tall trailers. The channel height, if we measure the channel height, it's gonna be right at eight inches. The width, which will always be measured inside-to-inside, is right at three inches.
And this is a heavy-duty steel construction, has a nice primed finish to it. In the very back here it has this composite master cylinder, which is durable and efficient. Does use glass-reinforced nylon construction to help resist rust and corrosion, and the master cylinder has a large reservoir, provides increased capacity for the brake fluid. And, if you notice on the top right here, it uses the automotive-style diaphragm cap, which creates a completely enclosed system, helps prevent contamination of your brake fluid. Now, it does come with this breakaway cable and the hook on the end.
And now this is required by law because it does prevent a trailer runaway situation, and the way it does that is, you see this hook with the keeper on it This will hook to your tow vehicle. So, when this is hooked to your tow vehicle, this cable will be stretched out, and if, by chance, this trailer come disconnected, it would pull on this cable, which would activate that lever, and then this, in turn, will supply that hydraulic pressure at your master cylinder to engage your trailer brakes and stop the trailer, so it'll prevent a runaway situation if it became detached. Now, this is a weld-on installation. It does mount to a straight three-inch-wide trailer tongue. This part is made in the USA.
Again, the application, this is for trailers with hydraulic drum brakes. Gross towing weight capacity on this is 20,000 pounds, tongue weight is 2,000 pounds. This does go by a model number of DA20. And one last note I do want to mention for you: because this actuator does not include a reverse lockout, it is recommended that you equip your trailer with either a reverse lockout solenoid that'll install back here on this master cylinder, or for your trailer to have free-backing brakes so that you can drive in reverse without the actuator triggering your trailer's brakes. But that should do it for the review on the Demco eight-inch adjustable channel down hydraulic drum brake actuator with the 20,000 pound gross towing weight capacity.
Ratings & Reviews
Thanks you! a great experience with the ordering and receiving my parts that I needed. I would recommend Etrailer.com to anyone needing competitively priced and quality parts fast.
Etrailer is the best store for parts.best prices,fast deliver,on time and safe,300 per cent hapy.the etrailer be mi store for ever.
Really happy with customer service and flexibility with shipping to Hawaii.
I think the demco actuator is grate
excellent quality, unbelievable delivery time.
Excellent product,service and price. I was notified at every stage where my item was on its journey without contacting etrailer other than placing my order. They have their "stuff " together.
Package wasn't the greatest, it was a heavy item and should have been packaged a little better, box was torn and one of the clips that holds the pins in place was missing
We're replacing old brake units on our fleet of tank trailers. These Demco actuators have a longer adjustment channel than the ones we could get locally, and they were cheaper. Great customer service also!
It does the Job. I tried to talk them in to going with an electric over hydraulic Disc system but the did not want to spend the money with this set up at least is has some brakes.
It worked out very well for us and was very affordable.
Anna did a GREAT job on getting the trailer parts I needed give her a raise :-)
Great quality excellent service
The product delivered was exactly what we ordered. It arrived within only a few days and the package showed up with zero damage. We will continue to order from eTrailer. 5 Stars!!
Quality is great and exactly what I was looking for in a Brake Actuator. Customer service was super friendly and online invoice and tracking was speedy and easy to obtain! Highly recommend.
Worked perfect, exactly as described.
A perfect fit and it took paint beautifully. Upon brake testing, it performed as an OEM! Customer Service was extraordinary.
Welded it together, haven't used it yet.
I am building a very strong utility trailer for a Mustang Skid Steer- I'm a welder by many years- and strong matters. I will put a 'dully' axel under a dump truck body with hydraulic breaks- thus you product was a perfect fit- strong, functional and safe. Thank you for your design intelligence and craftsmanship. I am set up for two trucks- a big one, Mack B-81SX, and a pick-up.
Well built just replaced a old unit that been sitting for years and had been jackknifed
we received in the hitch, we installed it without a problem.
the tech tried to beleed the brakes.
the tech was having problems with the master cylinder sticking.
we ordered in a replacement master cylinder in. after the new master cylinder was installed the tech bled the brakes with no issue. we received the hitch in with a bad master cylinder
Ordering was easy delivery was quick.
Excellent quality for use on trailers!
Info for this part was:
At etrailer we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.
Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.
Error submitting comment. Please try again momentarily.