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Demco Hydraulic Brake Actuator w Drop - Drum - Primed - A-Frame - 2" Bulldog Coupler - 8,000 lb
(42 reviews)
Price: $358.48
In Stock
Demco
Demco Hydraulic Brake Actuator w Drop - Drum - Primed - A-Frame - 2" Bulldog Coupler - 8,000 lb
Part Number: DM8509612
In Stock
$358.48
Retail:$461.12
You Save: $102.64
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- All Info
- Reviews (42)
- Q & A (0)
- Photos
Demco Brake Actuator - DM8509612
Highlights
- Smooth, Automatic Braking: Surge design activates trailer’s drum brakes as you slow down.
- Strong Pulling Power: Rated for 8,000 lbs GTW for heavy-duty towing.
- Secure Connection: 2" Bulldog Collar-Lok coupler grips the hitch ball tight for a solid link.
- Built for Long Life: Composite master cylinder and glass-reinforced nylon resist rust and wear.
- Easy Height Match: Built-in 4" drop helps level trailer to tow vehicle.
- Ready for Custom Setup: Weld-on fit for 50-degree A-frame trailers with hydraulic drum brakes.
Features to know about
Solid Replacement for Worn-Out Actuators: Heavy-Duty 8,000 lb Capacity
This actuator is built as a direct replacement when older or discontinued models wear out. With a 8,000 lb gross towing weight, it’s tough enough for heavy-duty use. The Bulldog Collar-Lok coupler locks tightly around a 2" hitch ball, giving a solid, no-wobble connection that holds up to real work. The built-in 4" drop helps line up your trailer height without extra attachments.
Long-Lasting Brake Performance: Composite Master Cylinder with Large Reservoir
The master cylinder is made from glass-reinforced nylon, so it won’t rust or corrode like metal versions. It also has a large reservoir that keeps more brake fluid on hand to reduce refills and maintain braking pressure over long trips. The automotive-style diaphragm cap seals the system to keep dirt and moisture out. Every stop feels smooth thanks to the acetal copolymer lining that lets the actuator telescope in and out easily.
Simplified Setup: Weld-On A-Frame Mount with Primed Finish
This unit welds directly onto a standard 50-degree A-frame tongue, making installation straightforward for DIY builders or anyone upgrading an older trailer. Since it comes primed rather than painted, you can weld without burning off finish and then paint it to match your trailer afterward. It’s a clean way to mount a new actuator without extra prep work or disassembly.
Backup Safety Built In: Ready with Breakaway System
A built-in breakaway feature adds peace of mind when towing. If the trailer ever disconnects from the hitch, the breakaway lever engages the brakes automatically to bring everything to a stop. When you’re ready to reset it, you can lift the flat emergency lever spring with a screwdriver and move the lever forward until it releases—quick and easy without removing parts.
Adaptable for Reverse Maneuvers: Optional Lockout Kits Available
This actuator doesn’t include a reverse lockout, but it’s ready for one if you need it. You can add the Manual Reverse Lockout Kit #DM5939 or an Electric Reverse Lockout Solenoid Kit #DM5837 to keep brakes from engaging while backing up. Either kit fits right onto this DA91 model, letting you set up your trailer exactly how you want it without swapping actuators later.
Specs
Application
- Application: 50-degree A-frame trailers with hydraulic drum brakes
Compatibility
- Ball size: 2"
Weight and Capacity
- Gross towing weight: 8,000 lbs
Dimensions
- Drop: 4"
Model Information
- Model number: DA91
- Warranty: 1-Year warranty
Note
- Important: Because this actuator does not include a reverse lockout, it is recommended that you equip your trailer with free-backing brakes so that you can drive in reverse without the actuator triggering your trailer's brakes.
8509612 Demco DA91 Hydraulic Trailer Brake Actuator for Drum Brakes - A-Frame - 2" Ball Bull Dog Drop Coupler - 8,000 lbs
Customer Satisfaction Score:
86% were satisfied with this product
14% of customers were not satisfied
- Arrived Damaged
Ratings & Reviews
4.9
42 reviews
by:
John X
10/07/2021
Thanks for your help in these trying times. I am restoring the surge brake operations to a 1985 Wells cargo enclosed trailer and performing all of the work myself. Not an easy task on a 36 year old trailer purchased new. I received this part and it is fantastic and arrived many days ahead of the projected delivery date. My prior orders also arrived early and the trailer brake parts and lines fit perfectly. Thank you for providing the service and knowledge to get me what I needed to restore an obsolete trailer. I can provide photos on completion. I may need to order new parts again in 36 years, I will be 94.
by:
Brian
08/13/2024
Good product for a reasonable price. Product availability and service was excellent.
by:
Dean
10/21/2022
by:
Rick
05/07/2025
by:
S
07/09/2025
The weld on installation matched the trailer tongue angle perfectly and is a very rugged build. I connected the hydraulic line to the original brake tubing, bled the brake fluid through the system using pressure with the break away lever and put the trailer back to work. The braking power is smooth and consistent. The only trouble is when I back the trailer up an incline. I would purchase the backing option lever so you don’t have the trouble backing the trailer putting on the brakes.
by:
Frank R. Eview
12/13/2025
Awesome unit, but did not come with installation or system bleed instructions.
by:
R
06/14/2023
excellent!. I painted with the trailer color
by:
Michael
07/08/2021
Yes i recieved the device , I'ts better than i expexted , very well built , Can definetely handle more weight than designed for, P/S I invented the device about 45 years ago. The device takes the shifting weight away from the hitch and tong of the trailer. The first device used a coil spring, The device i recieved uses a shock works the same as a coil spring.
by:
Greeno,
09/30/2018
The product was just what I expected. The real story was that etrailer had a delay in shipping due to a manufacturer issue. Etrailer stayed in constant contact with me and made sure I was up to date on every stage of the order. AAA+ service...!!!
by:
Jerry H
06/08/2020
Product has met my expectations. The customer service at etrailer is fantastic.
by:
Rcmedic
08/15/2020
Very impressed! This will be perfect for my trailer rebuild.
by:
Jeremy
04/18/2024
Amazing upgrade from magnetic brakes! Brittany was friendly, prompt, knowledgeable.
by:
Paul
01/30/2023
far superior to what it is replacing. well constructed, fast shipping.
Thanks again for supplies a quality product keep it up!
Thanks again for supplies a quality product keep it up!
by:
Fred
04/16/2025
Really pleased on the outcome. I did have to paint where I had to weld. Would be nice to have the color to match the metal.
by:
Daniel
06/28/2020
Have not installed yet, but the product appears to be of high quality and heavy weight steel. Looks great.. would reccomend to anyone!
Daniel
7/6/2021
Great product!!! Would reccomend
by:
Robert
10/05/2018
Very good product. I have been a fabricator for 42 years, and I will say this is very well made. etrailer.com is a great place!
by:
Carl
03/31/2022
Very happy with my purchase. It was a good price, easy to order and was received in short time. Thank you!
by:
Alex f
09/08/2019
this hitch was by far beyound my expections they will get most of my business
Alex F.
9/10/2020
12.500 clamshell surge works execellent thks
by:
Skyler
03/15/2022
Needed this for a water trailer. Couldn’t find one locally. Ordered and received very quickly. Item was as pictured and looks like it should work great!
by:
Chad B
02/28/2017
The people at E-trailer were very helpful and the product that came was exactly what i needed.
by:
Gregory
09/25/2019
Super replacement and much cheaper than the bulldog style.
by:
Deb H
09/06/2017
Excellent product. Exact product as shown. Quality materials. Quick to ship and receive.
by:
Rob U.
12/01/2014
Extremely happy with service and product. Thank You!
by:
Marcel
03/09/2023
Perfect , the delivery was faster than expected. The product is real good quality.
Thanks for your great service.
Regards,
Marcel
Thanks for your great service.
Regards,
Marcel
by:
Mario
09/20/2023
Great design. Easy to install. Very sturdy and excellent updated features
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Show More Reviews
See what our Experts say about this Demco Brake Actuator
- Replacement Surge Brake Actuator For Drum Brakes On 6,000LB Boat Trailer w/ Atwood A-Frame ActuatorI recommend replacing your obsolete Atwood surge coupler with the Demco Hydraulic Brake Actuator # DM8509612. This coupler is rated for trailers up to 7,000lbs and connects to the vehicle with a 4" drop coupler accepting a 2" hitch ball so it will be similar in height to your current coupler. This Coupler will weld on top of your current 50 degree a-frame but you will want to find some steel to close off the exposed openings in your frame and tie the bottom of the frame together as well.
view full answer...
- How to Release the Breakaway on the Demco Hydraulic Brake Actuator Part # DM8509612Are you referring to the breakaway or lockout on the Demco Hydraulic Brake Actuator part # DM8509612? If you are referring to the breakaway then there is a lever on the top of the coupler which has two positions, one for brakes on (red) and one for brakes off (green). If you are referring to the lockout then this unit does not come with a lockout mechanism. Therefore, in order reverse the trailer without having the brakes lock up you would need to either use free-backing brakes or a manual...
view full answer...
- Recommended Surge Brake Actuator For Demco DT6000 Trailer With Drum BrakesI would be happy to help! As long as the A-Frame on your trailer is the standard 50-degree angle then the best option to replace your current surge brake actuator would be the Demco Hydraulic Brake Actuator w Drop - Drum - Primed - A-Frame - 2" Bulldog Coupler - 7,000 lb # DM8509612. This actuator will weld right on to your A-frame, has a 7000lb trailer weight rating, uses a standard 2" hitch ball, and is designed specifically for drum brakes like your Demco DT6000 trailer has. Now this...
view full answer...
- How Does Demco Brake Actuator DA91 Reset BreakawayI checked the manual for the Demco DA91 actuator part # DM8509612 and if the lever is pulled it can be disengaged by using a screwdriver to lift upward on the front of the flat emergency lever spring while pulling lever forward till it releases.
view full answer... - Manual Reverse Lockout for Demco D91 Trailer Brake ActuatorsYes! The manual reverse lockout kit you are looking for is the # DM5939 for D91 Demco Hydraulic Trailer Brake Actuators. I have linked the product and installation instructions to this page for your convenience.
view full answer...
- Reverse Lockout Options For a Demco DA91 Surge Brake ActuatorYou can add a Manual Reverse Lockout Kit # DM5939 or Electric Reverse Lockout Solenoid Kit # DM5837 to the Demco Hydraulic Brake Actuator # DM8509612 to get the DA91 surge coupler with a reverse lockout.
view full answer... - Recommended Replacement Hydraulic Actuator For An Atwood # 82654Hey John, I wasn't able to find any info on the Atwood 82654, but I'm assuming because you were looking at a 2" coupler with a 7K capacity that's what your coupler is designed for. If this is the case then I recommend the Demco Hydraulic Brake Actuator w Drop # DM8509612. This actuator is compatible with 50-degree A-frame trailers with hydraulic drum brakes and comes with a Bulldog coupler lock to secure the trailer fast and easily. It doesn't come with a reverse lockout so you'll need...
view full answer... - Best Replacement Reverse Lockout Solenoid for Demco Hydraulic Brake Actuator # DM8509612We do have a replacement reverse lockout solenoid for the Demco Hydraulic Brake Actuator # DM8509612, but the Replacement Solenoid Valve # T4748800 that you referenced is not designed and has not been tested to fit the Demco actuators. Instead you will want part # DM11993 for just the solenoid or part # DM5837 for the kit that includes the solenoid cover. These are designed specifically for the Actuator # DM8509612. I have attached a link to an installation video of this solenoid for...
view full answer...
Do you have a question about this Brake Actuator?
Info for this part was:
Edited by:
Leah B
Written by:
Lindsey S
Installed by:
Jeff D
Expert Research:
Jameson C
Updated by:
Laura H
Updated by:
Wilson B
Video Edited:
Dustin K
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Rcmedic
8/16/2021
I am very happy. It works great.