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  1. Brake Actuator
  2. Demco
  3. Surge Brake Actuator
  4. Drum Brakes
  5. 2 Inch Ball Coupler
  6. 7000 lbs GTW
Demco Hydraulic Brake Actuator - Drum - Zinc - 2" Ball - 7,000 lbs

Demco Hydraulic Brake Actuator - Drum - Zinc - 2" Ball - 7,000 lbs

Item # DM72VR
Our Price: $207.16
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Brake Actuator
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Shipping Weight: 20 lbs
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Surge-type actuator features a corrosion-resistant composite master cylinder and durable zinc plating with a 120-hour salt spray rating. EZ-Latch coupler mechanism makes hookup a snap. Bolt-on application. 1-800-940-8924 to order Demco brake actuator part number DM72VR or order online at Free expert support on all Demco products. Great prices and Fastest Shipping for Demco Hydraulic Brake Actuator - Drum - Zinc - 2" Ball - 7,000 lbs. Brake Actuator reviews from real customers.
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  • Reviews (73)
  • Q & A (0)
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Demco Brake Actuator - DM72VR

  • Surge Brake Actuator
  • Drum Brakes
  • 2 Inch Ball Coupler
  • 7000 lbs GTW
  • Bolt-On
  • No Lockout
  • Straight Tongue Coupler
  • Demco

Surge-type actuator features a corrosion-resistant composite master cylinder and durable zinc plating with a 120-hour salt spray rating. EZ-Latch coupler mechanism makes hookup a snap. Bolt-on application.


  • Hydraulic actuator activates trailer's brakes when tow vehicle slows or stops
  • EZ-Latch coupler mechanism for simple, secure hookup and disconnect
    • Lets you hook up when latch is in closed position - just drop coupler over hitch ball and latch will snap into place
  • Zinc plating offers corrosion resistance
    • 120-Hour salt spray rating
  • Composite master cylinder is durable and efficient
    • Glass-reinforced nylon construction resists rust and corrosion
    • Large reservoir provides increased capacity for brake fluid
    • Automotive-style diaphragm cap creates completely enclosed system to help prevent contamination of fluid
  • Large rear rollers allow for easy movement and smooth operation
  • Breakaway included
    • Snap hook on safety cable ensures secure connection to breakaway lever
  • Heavy-duty steel construction with sturdy, reinforced outer casing
  • Bolt-on installation
    • Requires 2-1/2" x 4-1/2" Grade-5 bolts (not included) for mounting
  • Made in the USA


  • Application: trailers with hydraulic drum brakes
  • Ball size: 2"
  • Gross towing weight: 7,000 lbs
  • Maximum tongue weight: 700 lbs
  • Mounting: straight, 3" wide trailer tongue
  • Model number: DA70
  • 1-Year warranty

Note: 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.

When you apply the brakes in your tow vehicle, deceleration occurs and momentum pushes your trailer toward the rear of your vehicle. With surge brake systems, the hydraulic actuator is triggered as your trailer moves forward, once your tow vehicle starts to slow down. When this happens, the actuator contracts, applying force to its master cylinder. This in turn supplies the necessary hydraulic pressure to engage your trailer's brakes.

EZ-Latch Coupler

Cast Coupler Cutaway

This coupler features a simple-to-use latching mechanism known as the EZ-Latch. With this mechanism, hooking up is as easy as dropping the coupler over your trailer hitch ball. The latch does not need to be tugged or manually activated to allow the ball into the coupler socket, nor does it have to be secured in place. Just make sure that the coupler is properly lined up with the ball when you lower it, and the rest is automatic. Disengaging the coupler is just as effortless. Simply lift up the handle and the coupler socket will automatically release its grip on the ball.

Demco EZ-Latch in Use

The contoured, low-profile design of the latch handle helps protect the coupler from damage by allowing any potential hazards - from debris on the road to your ball mount backing into the coupler - to simply slide over the top. This helps prevent anything from getting under the latch handle and releasing the ball, and it can also limit any damage to the coupler should an impact occur

Unlike most couplers, which have a pin hole on the handle latch, the EZ-Latch coupler features a hole on the side of the coupler itself. Inserting a coupler lock through this hole will keep the latch from lifting, preventing disconnect and theft.

Sturdy, Corrosion-Resistant Construction

Made of sturdy steel, this hydraulic trailer brake actuator features a durable zinc coating that is designed to limit rust and corrosion. This zinc coat has a 120-hour salt spray rating. In addition, the composite master cylinder is made of corrosion-resistant glass-reinforced nylon to further ensure durability.

8705001 Demco DA86 Hydraulic Trailer Brake Actuator for Drum Brakes - 2" Ball Easy-Latch Drop Coupler 0 7,000 lbs
Replaces Demco DA86 and 8605001

Customer Satisfaction Score:

Customer Reviews

Demco Hydraulic Brake Actuator - Drum - Zinc - 2" Ball - 7,000 lbs - DM72VR

Average Customer Rating:  4.8 out of 5 stars   (73 Customer Reviews)

Surge-type actuator features a corrosion-resistant composite master cylinder and durable zinc plating with a 120-hour salt spray rating. EZ-Latch coupler mechanism makes hookup a snap. Bolt-on application.


I’ve owned this for 1 year now and have towed about 3,000mi at a 4K lb capacity - it works great and have had zero issues. Honestly this is the easiest hitching mechanism I’ve used, and there’s no need for a lock pin. Goes on smooth and releases easy every time. I highly encourage cutting off your old surge hitch and replacing it with this one, so much time saved with how easy it is. Even bleeding the brakes was a breeze by pulling the emergency lever by hand. Great product.


The hitch was good. The instructions weren't complete. There's no reference to how to release emergency lever. No hardware provided. For this price it should have. I used grade 8 bolt setup with washer, lock washer and lock nut. The install of brake valve was tricky. Overall time to change it was less than 20 minutes. Most of my time was spent installing brake line. For the trouble of an incomplete video demonstration, no hardware, and no clear instruction of emergency lever I'm giving it 3 stars. Overall the hitch worked and was a good upgrade.


This actuator works great so much better than my old one I had to lock out when I backed up but not this one easy to get hitched up to.


much improved from the old coupler I replaced which was completly shot. the ez latch feature is awesome. very easy to install...just had to re prime the brakes.


Unit fit trailer as expected. Seems to do it’s job well! E-trailer delivers again.


i purchased this unit along with the electric lock out solenoid. they were priced excellent and arived promtly. very high quality units and very easy to install. only wish a page on how to bleed the unit came with it, instead of having to hunt one up on the internet. after finding instructions on how to bleed th unit it was quite simple and easy.very satified with the purchase


works great!


Great customer service


We have only used the trailer a few times but so far, so good :)


Great product and very easy to install. The holes lined up with the existing ones. I do wish it came with the new bolts as it would make it easier to install, hence the 4 stars.

It’s still working great and love how easy it is to hook up to my receiver.
Bryant - 06/02/2022


Nice unit. Two of the holes lined up with my old Attwood unit but looked like it sat a bit high. Instructions as to proper install would have helped. Drilled 3 new holes and good to go. Took a bit of work and bending to get my brake line to connect but worked out fine in the end.


Direct replacement for older model. Customer service kept me up to date on delivery which was very much appreciated. Worked great with the Demco DA66B lockout solenoid and cover fit perfectly.




Good service and timely delivery of good products. Have the right parts delivered the first time means less headaches. Only shop here for my trailer needs. They have everything.


Installed this part in replacement of an Atwood 61101 on my four winns trailer. It bolted right up. I added the reverse lockout solenoid. Well built part that arrived quickly. Thanks!


Bolted right up to the standard 3" spread bolt pattern. One point of caution. See how the steel is doubled up when looking at it from behind? If your old one was not, you will need longer bolts. Just make sure you have 1/2-13 x 4.5" bolts on hand before install. Your old ones may be too short. I had to run to Lowes for bolts to complete install. 5 stars had it come with bolts.


Quick shipping, great product. Very easy install.


This new hitch (quick coupler) design is very cool. Installation is easy and it fit perfectly.


Fit perfectly!


Great replacement for the (almost) 30 year old Dico actuator, which was completely worn out. The auto locking ball latch is a great feature too.


Perfect for application and great price and super fast shipping


Quality product. Easily replaced my old Atwood 171 coupler. Delivered days before advertised date.

I called Demco for some technical information. Although the instruction clearly state to bolt the unit on, Demco advised against welding this coupler to my trailer.


arrived on time. Packaged good. Have not mounted on trailer yet .


The fitting on the end of master cylinder was cross threaded. I recapped it. I really hope it doesn't leak, it's too late in the game to get another one, we leave in a week. Have other things to do.


Fit right on my older double axel boat trailer. Very solid construction. The EZ hitch is actually a very nice feature. Great product.

Show More Reviews

See what our Experts say about this Demco Brake Actuator

  • What is Master Cylinder of Demco Trailer Brake Actuator # DM72VR Constructed Of
    The master cylinder (reservoir that holds the brake fluid) used in the Demco Trailer Brake Actuator # DM72VR is constructed of a fiberglass reinforced nylon composite that will not corrode, which makes this actuator perfect for marine applications.
    view full answer...
  • How to Bleed Trailer Surge Brakes
    I attached a video that details how to bleed surge brake actuators for you to check out. First top off the master cylinder with appropriate fluid. Next you will want to pump the fluid from the master cylinder. You can do this by unbolting the plate that holds the lever in place and then use that lever to actuate the master cylinder and force the fluid through. On some units, you will have to manually activate it at the point where the hitch ball moves in and out. The model in the video...
    view full answer...
  • Will Trailer Brakes Lock When Backing Up Trailer w/ Demco Hydraulic Trailer Brake Actuator # DM72VR
    I can understand how this can be a bit confusing. Brake actuators, like the Demco Hydraulic Trailer Brake Actuator, # DM72VR, with no lock-out are typically more economical and are perfect for trailers equipped with free-backing brakes because the lock-out is not needed. As for whether or not you can back up slowly without locking up the brakes is going to depend on the weight of your trailer and whether you are on level ground. A very heavy trailer is going to engage the brakes much...
    view full answer...
  • Truck and Trailer Shakes When Brakes Are Applied
    When it comes to your trailer shaking when the brakes are applied, it sounds like you may have a clogged brake line. In this case I recommend bleeding the brakes. I have included a video which goes over the process. I would also check your brake adjustment. After completing these steps, if you are still experiencing issues send me an email and we can continue the troubleshooting process.
    view full answer...
  • Difference Between Demco Hydraulic Trailer Brake Actuator DA66B, # DM72VR, and Previous DA66 Model
    I spoke with my contact at Demco and he said that there really is no difference between Demco Hydraulic Trailer Brake Actuator DA66B, # DM72VR, and the DA66 that you have on your trailer except the DM72VR has a capacity of 7000 pounds. Except for that they just did a name change. These actuators do not include a reverse lockout
    view full answer...
  • Selecting a Surge Coupler for a Boat Trailer
    In order to replace your boat trailer surge coupler you will need to match a number of your trailer's characteristics. You need to select a coupler for the type of hydraulic brakes you have, either disc or drum. Couplers for each type vary in their pressure rating (1500-psi for disc, 1000-psi for drum). You also need to match the coupler to the size of your trailer's tongue and to the gross weight of the boat/trailer. I was able to find the weight of the Allante 545 boat itself (approximately...
    view full answer...
  • Will Demco Hydraulic Trailer Brake Actuator Work for 4 Breaking Wheels on Tandem Axle Trailer
    I spoke with my contact at Demco and he said the Demco Hydraulic Trailer Brake Actuator # DM72VR will work for four breaking wheels on your tandem axle trailer. Please not that 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. I have included a video review of this surge-type actuator for you to check out.
    view full answer...
  • Key Differences Between Disc Brake and Drum Brake Trailer Coupler and Brake Actuators
    Drum brake actuators and disc brake actuators use different master cylinders. A disc brake actuator producer a higher psi than a drum brake actuator so the fittings will be a little different as well. The drum brake master cylinder will have a check valve in it that reduces the amount of psi the system puts out. The disc brake models do not have this valve because more pressure is needed to actuate disc brakes The problem could be air in the lines and/or pistons in the calipers that are...
    view full answer...
  • Advice for Removing Deteriorated Master Brake Cylinder Cap on Hydraulic Brake Coupler
    The challenge here is to keep the remains of the cap in one piece long enough to remove it. I would suggest mixing up some 2 part epoxy and coating the cap with it. If you are careful to avoid getting the epoxy down into the threaded portion of the cap, once it cures you should be able to get the cap off. If you should get pieces of the cap into the master cylinder, most hydraulic couplers are set up so that the master cylinder is removable, you could remove it if needed and clean it out.
    view full answer...
  • How To Bleed Trailer Brakes
    You are in luck! We happen to have a video on the proper procedure for bleeding trailer brakes. I have attached the video below as well as outline the method here for you. First top off the master cylinder with appropriate fluid. Next you will want to pump the fluid from the master cylinder. You can do this by unbolting the plate that holds the lever in place and then use that lever to actuate the master cylinder and force the fluid through. On some units, you will have to manually activate...
    view full answer...
  • Where Does Clip for Breakaway Kit Connect to for Hydraulic Actuator
    The cable that comes on the Demco Hydraulic Trailer Brake Actuator # DM72VR is the breakaway kit. Since this is intended to activate the brakes on your trailer in the event that the trailer becomes uncoupled you will want to attached the clip at the end of the cable to one of the safety chain loops on your trailer hitch.
    view full answer...
  • Thread Size of Brake Line for the DA66B Demco Hydraulic Trailer Brake Actuator
    The Demco Hydraulic Trailer Brake Actuator # DM72VR accepts a standard 3/16 inverted flare brake line. I reached out to my contact at Demco who confirmed this.
    view full answer...
  • Availability of Surge Coupler that Can Fit on 3 inch Wide Trailer Frame
    3 inch wide frame channel is actually very common for trailers with surge brakes like boat trailers so we have the Demco part # DM72VR which would fit and work well. This is a drum brake surge actuator for a 2 inch hitch ball that has a 7k capacity. I attached an install video for this coupler for you to check out as well.
    view full answer...
  • Why Would Trailer Brakes Stop Working After Replacing Hydraulic Brake Line
    Sounds like you replaced a hydraulic brake line and now the trailer brakes do not seem to be working. Typically when this happens it's because the brakes need to be bled. When you open up a brake line it allows air to get in the lines which will compress when the brakes are applied instead of activating the assemblies. What you'll need to do is bleed the brakes and you'll get the brakes to work again. I attached a video below that shows how to do this. First top off the master cylinder...
    view full answer...
  • Recommendation For Replacement For Hydraulic Trailer Brake Actuator
    Yes, the Demco Hydraulic Trailer Brake Actuator, Item # DM72VR, is a good replacement for your old brake actuator. It is designed to bolt-on and fits a 3 inch wide channel tongue. It requires 1/2 inch x 4-1/2 inch grade-5 bolts for mounting that are not included. Contact me if you have any other questions.
    view full answer...
  • Replacement Surge Brake Coupler for a 7,000 lb Drum Brake Trailer
    The Demco Hydraulic Trailer Brake Actuator # DM72VR is a replacement for a coupler that was a 2 inch ball and 7,000 lb capacity when used for drum brake applications. The bolt holes are 3 inches on center for mounting. I've attached a couple videos to assist. I can't find any information on the Atwood 8300 you mentioned, but if it meets that criteria it would be a direct replacement.
    view full answer...
  • Replacement 7K Surge Coupler for A-Frame and Straight-Tongue Trailers
    We do not offer parts for Reliable brand brake actuators but we can help you with selecting a new one if you cannot source the part(s) you need elsewhere. The page I linked for you displays all 6K-rated surge couplers. We have both drum brake and disc brake models with the different psi pressures required for each type of braking system. Just click on the type of brakes you have, the ball size required, your preferred installation method - weld-on or bolt-on and the trailer frame style,...
    view full answer...
  • Actuator Replacement Recommendation for Tie Down 660 for Drum Brakes
    We don't carry the Tie Down actuators so we aren't going to be able to set you up with a different check valve or master cylinder for what you'd need. We could only recommend a different actuator all together like the Demco part # DM72VR which is for drum brakes.
    view full answer...
  • Can Surge Brake Actuator for 3 inch Frame Channel Install on 2 inch Channel
    What you can do is weld 1 inch spacers on either side of your 2 inch frame channel and you'd be able to install a surge actuator for a 3 inch channel on it. The most popular surge actuator we have is the Demco part # DM72VR which is for a 2 inch ball, has a 7k capacity, and is designed for drum brakes. To see all of the surge actuators we offer check out the link I attached below.
    view full answer...
  • 1999 Shorelandr Actuator Replacement Recommendation
    Thanks for the picture of your trailer. What you have now is an Atwood actuator. Since we no longer carry that actuator best solution would be a # DM72VR since it's very similar and actually a bit more reliable than the Atwood couplers.
    view full answer...
    Image 1 for
  • Availability of Drum Brake Surge Actuator without Manual Reverse Lock Out
    Atwood doesn't, but we do carry other brand surge brake actuators that don't have manual lock outs. The Demco actuator part # DM72VR is a similar rated drum brake actuator that does not have a lock out. I attached an install video for this coupler for you to check out as well.
    view full answer...
  • What Brake Fluid Should be Used in Surge Brake Actuators
    DOT 3 or DOT 4 brake fluid is recommended for Demco brake actuators like the # DM72VR. You should never use DOT 5 as it will wear out seals very quickly.
    view full answer...
  • Surge Brake Actuator Recommendation for 1979 Wellcraft Sunhatch 196
    I'd recommend going with the Demco surge actuator part # DM72VR which is designed for a pole tongue trailer like your boat trailer, has a 6k capacity, is designed for drum brakes, and a 2 inch ball. This is our most popular surge actuator for boat trailers with drum brakes so it would work very well for you.
    view full answer...
  • How to Reset Breakaway Cable of Atwood Surge Brake Actuator
    If your emergency/breakaway brake cable has been pulled slightly that would be why the brakes aren't releasing like they are supposed to. You need to reset it so that the brakes will release like they should. To reset the breakaway cable on the Atwood Hydraulic Brake Actuator, item # 84132, you will need to feed the cable back through the opening in the top of the housing so the push rod can be properly released into the master cylinder. Once this is done, pressure from the master cylinder...
    view full answer...

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Info for this part was:

Employee Mike L
Expert Research:
Mike L
Employee Jameson C
Expert Research:
Jameson C
Employee Lindsey S
Edited by:
Lindsey S
Employee Jeff D
Installed by:
Jeff D
Employee David F
Installed by:
David F
Employee Chris R
Video Edited:
Chris R
Employee Wilson B
Updated by:
Wilson B
Employee Mike S
Written by:
Mike S
Employee Schuyler H
Video by:
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