bing tracking image
  1. Brake Actuator
  2. Demco
  3. Surge Brake Actuator
  4. Disc Brakes
  5. 2-5/16 Inch Ball Coupler
  6. 12500 lbs GTW
Demco Surge Brake Actuator w Drop and Electric Lockout - Disc - Zinc - 2-5/16" Ball - 12.5K
Demco

Demco Surge Brake Actuator w Drop and Electric Lockout - Disc - Zinc - 2-5/16" Ball - 12.5K

Part Number: DM8104311
In Stock
$465.99
Brake Actuator
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.
By submitting this form, you understand and agree to our Terms of Sale, Website Terms of Use and Privacy Policy.

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.

Product Images

Customer Photos

Need help with installation?
Locate installers near me
Heavy-duty and easy to use, this surge actuator engages your trailer's disc brakes and keeps them from locking up when you launch your boat. EZ-Latch coupler with a 4" drop keeps you from second guessing your connection. Made in the USA. 1-800-940-8924 to order Demco brake actuator part number DM8104311 or order online at etrailer.com. Free expert support on all Demco products. Great prices and Fastest Shipping for Demco Surge Brake Actuator w Drop and Electric Lockout - Disc - Zinc - 2-5/16" Ball - 12.5K. Brake Actuator reviews from real customers.
  • All Info
  • Reviews (142)
  • Q & A (0)
  • Photos

Demco Brake Actuator - DM8104311

Highlights

  • Easy Backing: Electric reverse lockout keeps brakes off when reverse lights come on.
  • Hitch Fast and Confidently: EZ-Latch drops onto a 2-5/16" ball and clicks securely in place.
  • Smooth Stops: Surge design automatically engages disc brakes as your tow vehicle slows.
  • Perfect for Use Around Water: Zinc plating with 200-hour salt-spray rating resists rust.
  • Strong and Long-Lasting: Heavy-duty steel body and aluminum master cylinder for durability.
  • Built for Heavy Loads: Rated for 12,500 lbs GTW and mounts on a 3" x 3" trailer tongue.
Made in USA

Features to know about

Confident Hookup Every Time: EZ-Latch Coupler with 4" Drop

The EZ-Latch coupler on this actuator takes the guesswork out of connecting to your 2-5/16" hitch ball. Just lower your trailer onto the ball and the latch snaps into place automatically—you’ll hear the metallic *clink* when it’s locked down tight. The low-profile composite handle is tough and resists bending or breaking, and the 4" built-in drop helps line up your trailer with your tow height so you don’t have to mess with extra adapters.

Cutaway view of Demco coupler showing internal latch and locking mechanism for hitch ball connection

Underside view of Demco EZ-Latch coupler with latch disengaged, showing internal coupler mechanism

Underside view of Demco EZ-Latch coupler with latch engaged and secured to hitch ball

Smooth Braking You Can Feel: Self-Lubricating Acetal Copolymer Liner

Inside the steel housing, the moving parts glide on a heavy-duty acetal copolymer liner that’s self-lubricating for long life and quiet operation. This design keeps the actuator telescoping smoothly as it compresses under braking and extends again when you pull away, giving your disc brakes consistent pressure without jerking or chatter. It’s built for steady, reliable braking that holds up over years of towing.

Close-up of hard plastic acetal copolymer liner inside Demco DA10 surge brake actuator

Easy Backing Without Brake Drag: Built-In Electric Reverse Lockout

Backing a loaded trailer uphill or into tight spots is simpler with the built-in electric reverse lockout. It connects to your reverse light circuit through a 5-pin, 6-pin, or 7-pole plug so when you shift into reverse, the solenoid automatically stops hydraulic pressure to your brakes. There’s no manual pin to fuss with—just back up smoothly without wheel lockup.

Backside view of Demco surge brake actuator showing electric solenoid and wiring for electric reverse lockout

Built to Last in Harsh Conditions: Zinc Plating and Aluminum Master Cylinder

The entire actuator is zinc-plated inside and out for rust resistance with a 200-hour salt spray rating, making it ideal for use around water or road salt. A heavy-duty aluminum master cylinder adds strength without corrosion, while the composite latch handle and internal components resist wear from years of exposure. Bolt it to a 3" wide trailer tongue using 1/2" x 4-1/2" Grade-5 bolts (hardware not included) and you’ve got a setup rated for 12,500 lbs GTW and 1,250 lbs maximum tongue weight that’s ready for serious work.

Demco coupler mounted on straight-pole trailer tongue showing installed appearance and fit

Safety Ready: Integrated Breakaway Cable

The included breakaway cable with snap hook is built right into the actuator housing. If the trailer ever separates from your hitch, it automatically pulls to engage the brakes and bring everything to a stop. It’s a simple safeguard that adds peace of mind every time you tow.

Specs

Application

  • Application: trailers with hydraulic disc brakes
  • Designed to bolt on top of: 3" tall x 3" wide trailer tongue
  • Bolts: 1/2" x 4-1/2" Grade-5 bolts (not included)
  • Bolt pattern dimensions: See below for bolt pattern dimensions

Technical dimension diagram showing 5-hole bolt pattern and measurements for Demco surge brake actuator

Weight and Capacity

  • Gross towing weight: 12,500 lbs
  • Maximum tongue weight: 1,250 lbs

Coupler and Drop

  • Ball size: 2-5/16"
  • Drop: 4"

Model and Warranty

  • Model number: DA10
  • Warranty: 1-Year warranty

8104311 Demco DA10 Hydraulic Trailer Brake Actuator for Disc Brakes - Electric Lock-Out - 2-5/16" Ball Easy-Latch Drop Coupler - 12,500 lbs

Installation Details DM8104311 Installation instructions



Customer Satisfaction Score:

Ratings & Reviews

4.6

142 reviews
Review sort icon
Heavy-duty and easy to use, this surge actuator engages your trailer's disc brakes and keeps them from locking up when you launch your boat. EZ-Latch coupler with a 4" drop keeps you from second guessing your connection. Made in the USA.

by:



by:

Bolted right up exactly like the old one, bled the brakes, hooked up 2 wires save time & $ compared to the original one which was b/o till November. Just haven't found a place to grease it yet



by:

It installed easily, fixed my problem, and works well. However, it's nearly inconceivable that it doesn't have a mechanical lockout built in. Since I prefer to maneuver my boat at home with the tractor, I will be fabricating a mechanical lockout - probably by pinning the large hole near the back of the movable portion and fabricating a steel spacer to wedge in the gap to the stationary housing. It will need to wedge in pretty tight since the total tongue movement is only about about 3/8".



by:

Great product but FYI, it is not a direct replacement for the comparable TITAN actuator.
Your brake line may be a few inches too short as mine was.
Super fast shipping!



by:

Works great!! Thank you



by:

Would like a manual with the actuator to insure my correct install.

Gwendolyn Y. profile picture
Etrailer Expert

Gwendolyn Y.

10/18/2024

Hey Robert! I have the instructions linked for ya.



by:

Very fast shipping. Good price and sales help! Thanks

John R. profile picture

John R.

9/30/2022

Great !!



by:

Customer service was very good. Excellent.
shipping info was accurate and the suggestion to try a product (actuator ) in stock sped up my getting the part to the mechanic who is going to install in the next couple of days.
Thanks Warren



by:

Great product and quick delivery



by:

Experience with Etrailer was great. They sent the part that I ordered and it was not damaged which was a plus. The actuator has been working great since then. I hope to get several years of service from this actuator without any issues.
Thank you Etrailer!

Happy Customer: Gus Rodriguez



by:

Prior to ordering, I was concerned about the length of the brake. Length end to end was provided, but I would have liked mounting area length (8 1/4"), and length behind the mounting (~11 1/4"). Communication was great and they kept me informed.

John profile picture

John

4/24/2023

I really like this hitch. Even when there is a lot of pressure on the hitch, I have no problem getting it off the ball. With the old hitch it would typically be a struggle to get disconnected.



by:

***BEWARE*** The brake actuator (complete tongue module assembly) was a nightmare to bleed brake system and after less than one year of installation the back up disengage piston exploded as I backed up for refueling the boat sending brake fluid all over my Ram tailgate destroying the paint job!!!
Many emails were sent to etrailer without any answer. Not happy with purchase at all. My boat trailer is now unusable and no reply’s from Etrailer.

Nick S. profile picture

Nick S.

9/15/2025

I am sorry to hear about your experience with us and the actuator. I will have someone from our Customer Service team reach out and see if there is something we can do to help you out with this issue.



by:

I didn't give all five stars because Demco has changed the design of the master cylinder, again! My first hitch from 2009 had a cast iron (I think) master cylinder casting which was very strong. Then they went to cast aluminum when the original was replaced in 2018. When I lost brake fluid during two different trips to the lake because of broken brake lines, it resulted in not handling the pounding when the hitch retracted on braking and the master cylinder cracked. The first two hitch attachments of the master cylinder to the underside of the hitch was via "blind" hole drillings and threaded so that it wasn't exposed to the brake fluid reservoir. This most recent design now has attachment holes drilled all the way through (probably to decrease production costs) and a rubber seal that mates up to the underside of the hitch. The bolts were coated with a sealant but I had to remove two of them to facilitate using my pressure bleeder thus causing the brake fluid to weep out until having to reseal them with silicone seal. I wish they had kept the blind hole drillings and cast iron instead of counting on thread sealant and a rubber gasket...!!!



by:

The actuator itself has been operating flawlessly but as previously documented via emails, the backup solenoid failed on the first usage (i.e., wouldn't release the brake fluid pressure when energized). I had to swap out my old solenoid and reuse it so that the actuator was fully functional. It seems that cheaper solenoids are prone to failure and are being installed on new actuators. I disassembled the failed solenoid, connected the solenoid to a 12.5 VDC power source, and found that the electromagnet wasn't strong enough to lift the valve plunger upon energizing when pressurized by brake fluid. I would suggest that the purchasing department return back to the older style, more reliable solenoids. That is why I only gave three stars on this review.



by:

Easy ordering online, prompt shipping and delivery. No issues at all. We will order from Etrailer again when parts are required.
Thanks

Mitchell profile picture

Mitchell

9/28/2020

The brake actuator works as it should. The mounting points matched up perfectly with the old original unit.



by:

Works ok. The reverse actuator lockout is a bit iffy and heavily depends on good ground connection. Using the trailer itself as ground wasn’t sufficient, so I had to splice it to a dedicated ground wire. No manual bypass like other brands.



by:

Packaging of the product was very poor and the packaging arrived wide-open at my house with missing hardware. I emailed back Etrailer and I have yet to receive a response a week later.

Mike L. profile picture
Etrailer Expert

Mike L.

5/21/2026

If you're speaking of the 1/2" x 4-1/2" Grade-5 bolts used to mount the coupler to the trailer tongue, they aren't included. You'll want to source those from your favorite hardware store.



by:

The hitch was replacing a 18 year old hitch that had rusted out. It fit the existing holes without having to drill them out. I'm restoring a 19 year old Grady White 232 Golfstream. I'm looking forward to seeing how well the breaking system works.



by:

Good price and in time delivery.



by:

Found better pricing here, than any other place.



by:

Works great and even lined up with existing holes on my trailer.



by:

Great quality ,service,easy installation and fast shipping.



by:

Quality built unit that dropped for a perfect fit. Could not have been easier!



by:

Haven't installed yet, but superfast shipping! Love the features of the dropping on the ball with the hitch closed, and the addition of the solenoid lockout for reverse. This will replace the Titan 10 on my trailer now. Very happy with the quality of the unit. Joy was very helpful in the ordering process. Thanks



by:

After finishing my 4th and final boat trailer I purchased the hydraulic break actuator, Demco,12,500 lb. for 200.00+ cheaper than I could find anywhere, the etrailer staff helped with advise and follow-up; exceptional service.
51 years of commercial diving was all I work to restore now @ 80, but the spirit of the sport divers we work with, like this company, keeps me 'inspired', and I hope this inspires you too.

Brooke M. profile picture
Etrailer Expert

Brooke M.

7/10/2025

Consider me inspired! You've redone 4 trailers? I hope when I am 80 I'll be doing amazing stuff still, like you! What sorts of jobs did you work on as a professional diver?

Brook; T. profile picture

Brook; T.

7/11/2025

@BrookeM

25
25

See what our Experts say about this Demco Brake Actuator



< Previous
12



Do you have a question about this Brake Actuator?


Info for this part was:

Employee Leah B
Edited by:
Leah B
Employee Lindsey S
Written by:
Lindsey S
Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee Jeff D
Installed by:
Jeff D
Employee Laura H
Updated by:
Laura H
Employee Wilson B
Updated by:
Wilson B
Employee Dustin K
Video Edited:
Dustin K

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.