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.
This surge-type actuator is designed for serious hauling jobs. With a 20,000-lb gross towing weight and a 2,000-lb maximum tongue weight, it delivers reliable braking for big trailers that carry heavy equipment or materials. The hydraulic system automatically activates your trailer’s drum brakes when the tow vehicle slows down, giving you consistent control without needing an electric hookup.
The glass-reinforced nylon master cylinder resists rust and corrosion, so it keeps working smoothly even when exposed to moisture or road grime. Its large reservoir provides extra brake fluid capacity, which helps prevent the system from running low. The automotive-style diaphragm cap completely encloses the system to keep contamination out, so you get long-term reliability without frequent maintenance.
The 12" adjustable channel gives you five mounting positions for a coupler (sold separately). That means you can match up different hitch heights easily and tow your trailer level. The channel-down design adds more drop, which is especially handy for tall trailers that need a lower connection point. Whether you run a standard ball coupler, a lunette ring, or a clevis attachment, the setup stays straightforward and adaptable.
You can bolt this actuator directly onto a straight 3" wide trailer tongue using 1/2" x 4-1/2" Grade-5 bolts (not included) or weld it in place for a permanent fit. The primed steel finish gives you a solid base coat ready for paint, so you can match it to your trailer and protect against corrosion right from the start.
The built-in breakaway feature keeps your trailer safer by engaging the brakes if it ever separates from the tow vehicle. Inside, an acetal copolymer lining ensures smooth telescoping action every time you brake, so the actuator performs consistently under load and in emergencies alike.
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, we're gonna take a look at this Demco 12-inch adjustable channel down hydraulic drum brake actuator. Has a 20,000 pound gross towing weight capacity, and you can see, it has a nice prime finish to it. Now this hydraulic actuator will activate your trailer's brake when your tow vehicle will slow or stop. 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 a surge brake system like this, the actuator is triggered as your trailer moves forward once your tow vehicle starts to slow down, and when this happens is the inner slide of the actuator will contract and applies force to the master cylinder that's in the back here. And this in turn supplies the necessary hydraulic pressure to engage your trailer brakes and stop the trailer. Now, between these two, between the inner slide and the outer case, they use acetal copolymer lining, and it provides a nice, smooth operation as the actuator will telescope in and out. We mentioned up front here, you can see it has this adjustable channel, has five different mounting positions for your coupler. Now the coupler is not included.
We do sell those separately on our website. And this is a channel down design. You can see how it goes down further. This allows for a greater drop if you're towing tall trailers. Now, just to give you a few measurements.
The height on the channel we mentioned is 12 inches tall. The width, which is always measured inside the inside is three inches. This is a heavy duty steel construction, has a nice prime finish to it. Does use a composite master cylinder in the back here, which is durable and efficient. It is a glass-reinforced nylon construction, which resists rust and corrosion.
Offers a large reservoir, which provides increased capacity for the brake fluid. And up top here, uses an automotive style diaphragm cap, which creates a completely enclosed system to help prevent contamination of the brake fluid. Now, the breakaway cable and the hook, as you'll notice right up here at the top, it is all included and installed. And this part is required by law because it does prevent a trailer runaway situation. What happens is you take this hook with the keeper on it, and this will hook to the tow vehicle. And then this cable runs all the way back to the lever here. So what happens, if in this case it would detach from your tow vehicle, this cable would be pulled, which would activate the lever, which would again activate the pressure of the brake cylinder, which would bring the trailer to a stop. So it is required by law to have this breakaway cable on your trailer. Now this is a bolt on or weld on installation. You can see at the bottom here it does mount to a straight three-inch wide trailer tongue. And, again, it can be bolted on or welded on. This part is made in the USA. A few specs on this, the application, this is for trailers that have hydraulic drum brakes. Gross towing weight capacity of 20,000 pounds, maximum tongue weight of 2,000 pounds. This goes by a model number of DA20. But one last note I do wanna mention on this, because this actuator here does not include a reverse lockout, it is recommended that you equip your trailer with either a reverse lockout solenoid that will screw right into the back of the master cylinder here or to have 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 this Demco 12-inch adjustable channel down hydraulic drum brake actuator with the 20,000 pound gross towing weight capacity in the prime finish.
Customer Satisfaction Score:
92% were satisfied with this product
8% of customers were not satisfied
Ratings & Reviews
Victoria H.
11/19/2024
Hi Holger, this should've been packaged better. Let me make this right for you.
Condition: Surface Scratches
Notes: Item has minor cosmetic scratches and dings.
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.
Jeff M.
9/3/2025
No problems works as it should