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  1. Trailer Brakes
  2. Demco
  3. Hydraulic Drum Brakes
  4. 3500 lbs Axle
  5. 10 x 2-1/4 Inch Drum
  6. 14 Inch Wheel
  7. 14-1/2 Inch Wheel
  8. 15 Inch Wheel
Demco Hydraulic Brake Kit - Free Backing - Galvanized - 10" - Left/Right Hand Assemblies - 3.5K

Demco Hydraulic Brake Kit - Free Backing - Galvanized - 10" - Left/Right Hand Assemblies - 3.5K

Item # 40716-15
Our Price: $164.94
Trailer Brakes
Shipping Weight: 19 lbs
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Free-backing, driver's-side and passenger's-side brakes won't engage when you reverse, even if your actuator is activated. Galvanized steel resists rust, making the assemblies great for boat trailers. Fit 14" to 15" wheels. Great Prices for the best trailer brakes from Demco. Demco Hydraulic Brake Kit - Free Backing - Galvanized - 10" - Left/Right Hand Assemblies - 3.5K part number 40716-15 can be ordered online at or call 1-800-940-8924 for expert service.
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Demco Trailer Brakes - 40716-15

  • Hydraulic Drum Brakes
  • 3500 lbs Axle
  • 10 x 2-1/4 Inch Drum
  • 14 Inch Wheel
  • 14-1/2 Inch Wheel
  • 15 Inch Wheel
  • Marine Grade
  • Free Backing
  • Manual Adjust
  • Single Servo
  • Demco

Free-backing, driver's-side and passenger's-side brakes won't engage when you reverse, even if your actuator is activated. Galvanized steel resists rust, making the assemblies great for boat trailers. Fit 14" to 15" wheels.


  • Marine-grade hydraulic drum brake assemblies are great for boat trailers
    • Designed for use with surge-type trailer brake actuators
  • Sturdy, corrosion-resistant steel construction
    • Galvanized backing plates
    • Stainless steel spring hardware
    • Zinc-plated wheel cylinders
  • Free-backing design lets you back up without engaging the trailer brakes, even if the actuator is activated
    • Riveted, fall-away brake shoes only anchor on drums when brakes are engaged as trailer is moving forward
    • Periodic manual adjustment required
  • Adjuster plugs (included) cover access holes to keep dirt and grime out of the assemblies and off of the shoes
  • Left-hand (driver's-side) brake assembly and right-hand (passenger's-side) brake assembly included
    • Mounting bolts and hardware sold separately
  • Made in the USA


  • Dimensions: 10" diameter x 2-1/4" wide
  • Mounting flange bolt pattern: 4 bolt
    • Measurement between center of mounting hole to center of mounting hole: 2-3/4"
    • Diagonal measurement between mounting holes: 4"
  • Wheel size: 14" or 15"
  • Axle rating: up to 3,500 lbs
  • 1-Year warranty

Note: Because free-backing brakes are designed to eliminate nearly all friction between the brake shoes and the drum when you are driving in reverse, a trailer breakaway kit will not be effective should your trailer disconnect from your tow vehicle while you are backing up.

Free-backing brakes let your trailer move in reverse without the brakes being activated by your surge actuator. These brakes are needed if your actuator does not have a reverse lockout, which is a mechanism that ensures that the actuator does not activate when your rig moves in reverse.

Demco Free-Backing Brakes with Fall-Away Shoes

Each of these Demco free-backing brake assemblies has a fall-away shoe that is designed to provide full braking action when your trailer is moving forward and to supply only limited friction when the trailer is moving in reverse. This is largely due to the incorporated dual springs at the shoe's pivot point. (One spring sits on either side of the shoe lever, so only a single spring is visible when looking at the brake assembly.)

Demco Free Backing Brake Labeled Diagram - Right Hand Assembly

When your rig is moving forward and you engage the trailer brakes, each fall-away shoe expands normally, with the leading edge of the shoe catching the drum. This occurs because the plunger on the hydraulic cylinder pushes on the shoe lever, forcing the leading edge of the brake shoe into the drum. Once that edge catches, the dual springs at the shoe's pivot point facilitate braking by forcing the rest of the shoe to pivot into the drum. The action of the shoe against the drum provides the friction required for braking.

When you are driving in reverse, however, the hydraulic cylinder and the springs work against one another. Even though the plunger pushes on the shoe lever, the dual springs of the fall-away shoe overcome the pressure from the brake cylinder, keeping the leading edge from catching on the drum and ensuring that the shoe does not fully pivot into the drum. Because the shoe makes only slight contact with the drum, just enough friction is generated so that only a minimal amount of braking occurs when you are in reverse.

SB40716M Demco Galvanized 10" Marine Trailer Brake Assembly - Freebacking - Left Hand

SB40715M Demco Galvanized 10" Marine Trailer Brake Assembly - Freebacking - Right Hand

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Customer Reviews

Demco Hydraulic Brake Kit - Free Backing - Galvanized - 10" - Left/Right Hand Assemblies - 3.5K - 40716-15

Average Customer Rating:  4.9 out of 5 stars   (102 Customer Reviews)

Free-backing, driver's-side and passenger's-side brakes won't engage when you reverse, even if your actuator is activated. Galvanized steel resists rust, making the assemblies great for boat trailers. Fit 14" to 15" wheels.


2000 ez loader trailer complete brake job. 2 axle torsion suspension. All 4 axles . I ordered 4 complete brake /backing plate assemblies and 4 new hubs. My complete order showed up on time afew days later. After I got the trailer and boat jacked up and started to take things apart I overlooked not ordering the transitional flexible brake lines that go from the hard lines into the back of the brake assembly. After traveling for 30 minutes to a hydraulic brake line shop to have lines made up they told me they did not have the fittings I really needed these lines to get this job done for the weekend to get the boat out on the water. So I called etrailer and was connected to Tiffany who I must say provided the best customer service I've ever experienced she worked with me on getting the correct items and set up next day rush shipping. She even personally made sure that my order got out the door and called me personally to let me know . There aren't too many companies that goes to that length to serve their customers. The next day at 10 a.m. the were delivered to my front door. (From half way across the United States ) . I was trilled to say the least. Thank you etrailer and a special thank you to Tiffany. In customer service for your personal attention and follow up regarding my order.



The complete brake and line replacements our working great 1 year later. And I put alot of miles on my trailer both to salt water and fresh water.


After launching my boat, my left trailer wheel with drum brakes started locking up on my 2005 boat trailer. Thus, I decided to replace all brake and hub assemblies including both backing plates. I found all parts online from, and it was an easy repair.

I contemplated changing from drum to disc brakes at this time and get rid of the heavy hubs. However, I would have to replace the drum brake actuator with a higher pressure disc brake actuator, and I would have to run a wire to the reverse lights to keep the disc brakes from engaging when backing uphill.


Haven't used them yet because I have to install a new actuator... however these were an exact fit and easy replacement on my 1981 Somerset boat trailer.

Robert C.


Working fine after a year of use. Great product.


24 yr old boat trailer brake cylinder finally fails. Brake shoes very thin. Every thing rusty and dirty.
I look at cylinders only, pads only, then found these! Everything new at reasonable price and delivered on time.
First trip found them to be smooth in operation. did not jam on at the last minute like the old ones did. THANKS etrailer.


Hey George just got done installing your brake system on my Carkins dual axle boat trailer, what are nice product they went on beautiful no issues whatsoever extremely satisfied following is a picture of before and after , I just bought the boat and trailer and could not believe the condition of the brakes


I gave the brakes only 4 stars because I just put them on and have not road tested them. They look great for rust prevention as they are for a boat trailer, I will be road-testing them tomorrow, and I'm sure they will get 5 stars.


Repeat customer, quality parts and quality customer care.


Fast deliver and an exact fit on my Tracker Boat trailer


Everything was great except and fit like a glove. No issues at all.


I bought these right and left hydraulic brake assemblies for my boat trailer at a great price. I received my order one day earlier than promised. really rocks to satisfy it’s customers. They provided an awesome tracking link for me to review my order’s shipping progress. This is the best tracking link that have ever experienced. Both complete brake assemblies fitted perfectly in place of my old assemblies. On each Brake assembly, I just had to remove the 4 mounting bolts from the axle flange and the hydraulic hose. Then install the new complete brake assembly, tighten the 4 mounting bolts and makeup the hydraulic hose.. This made this brake job a breeze! It was a pleasure doing business with you.



Working great with no problems. Good product!


Product looks great, heavy-duty and ready for install! Would have given 5-Star if the shipping boxes weren't damaged.


It took to long to receive them,but Great service.


Great replacement. Took off the old crud and cleaned up the mount. The new assembly bolted right on.


Brakes work well and are a good value. I also bought an actuator and new lines to replace an existing, old trailer brake system.
The detailed descriptions of these products is great and helped verify that they would fit my trailer.
The gravity bleeding system that the etrailer video shows did not work for me.
I repeatedly pulled on the emergency breakaway handle on the actuator to fill and bleed the system.


Shipping time was quick ,direct
bolt on, seem to function well.
Over all good quality.
Used with the Demco Hydraulic Brake Actuator, to complete the restoration of the braking system.


Perfect fit, I had them installed in 20 minutes. Super fast delivery.


Very impressed with the speed of shipping. Wow! Very happy with the parts.


I ordered a set of complete galvanized trailer brake backing plates/linings/master cylinder, and a new surge coupler, and couldn't be happier with the quality, price, and very quick free shipping. Very easy on line ordering experience......


Perfect fit. Excellent quality with the lowest prices around. Received complete order in under 5 days. I found that customer service was extremely knowledgeable of the parts i needed and offered up the 3 options, good, better and best for my boat trailer brake assemblies. I will return to etrailer for all my boat trailer needs.


I primarily use this trailer in salt water and the shoes are holding up pretty good so far,I’ve put it in the water about 15 times now and shoes have no signs of cracks yet I usually replace em about every two yrs just as preventative maintenance.


Products are great but can’t say so for the customer service of took almost 2 weeks to get my products. I was going to order from [online] but I thought I would give etrailer the business. Never again.


I purchased these with new hoses and a new master cylinder, all from etrailer. After one year, they’re holding up great! I rinse them thoroughly since I launch in saltwater and I’m really happy with them.


Very pleased with these folks, shipping was very quick and the parts are top notch.


It was easy to select the trailer brake kit. The dimensions were right there so I could measure what I needed and order. Glad I read the reviews that said to purchase replacement hardware too. Quick delivery And I am all set


I bought a set of trailer brakes from, they were easy to install and function really good on my trailer. I talked with Robert over the phone at etrailer and he was extremely knowledgeable about this product and he helped me buy the correct brakes for my trailer. I receive my brakes three days after I ordered them, extremely fast service. I will use again to by parts for my trailer.

Show More Reviews

See what our Experts say about this Demco Trailer Brakes

  • Is Galvanized Coating Best for Salt Water Application for Boat Trailer Brakes
    The Galvanized Demco Hydraulic Brake Kit # 40716-15 is definitely the best coating that you can get for corrosion resistance. The other coatings are basically just different levels of powder coats while galvanized resists salt water much better. I do recommend rinsing your boat trailer off as well to help extend the life of the various components.
    view full answer...
  • Is Demco Hydraulic Brake Kit # 40716-15 Sold As Pair or Individually
    The Demco Hydraulic Brake Kit # 40716-15 that you referenced is sold as a set. This gives you both assemblies you'd need for a single axle. So since you have a single axle trailer you need to just order a quantity of 1.
    view full answer...
  • Replacement 10-Inch Galvanized Drum Brakes for Boat Trailer with 14-Inch Wheels
    If you cannot find a sticker or plate on your boat trailer axle you can still get in the ballpark on its weight rating based on the brake dimensions. All of our 10 x 2-1/4-inch drum brakes, both electric and hydraulic, that work with 14-inch trailer wheels will be rated for axle capacities from 3500-lbs on the low side up to 4400-lbs on the high side. The vast majority of these brakes are for 3500-lb axles so odds are good that is your rating. All brakes are shown on the linked page. Do...
    view full answer...
  • Complete Hydraulic Brake Assy. for 2006 EZ Loader Trailer with Oil Bath Hubs
    Yes, the Demco # 40716-15 Hydraulic Brake Kit will fit your needs for a 10" X 2.5" assembly. When measuring the drum use inside measuerments as shown in the attached photo. You will just want to confirm your flange bolt pattern is 4 on 4". Measurement between center of one mounting hole to center of the next mounting hole. I have attached another photo depicting this.
    view full answer...
    Image 1 for Image 2 for
  • Recommended Replacement Hydraulic Brakes with 10-Inch Diameter for a Boat Trailer?
    Knowing the inside diameter of the drum is the key piece of information we need; the brand of the assembly will not be a factor in determining what you will need to replace your hydraulic brakes. You mentioned your trailer's GVW, but it is the trailer's axle weight capacity which determines the size of the brake assembly you are going to need. For example, a drum with a 10-inch diameter like yours fits brake assemblies for a 3,500 lbs axle. For your boat trailer, I recommend the Demco...
    view full answer...
  • Is A Brake Flange With A Bolt Spacing Of 2-3/4" The Same As A Brake Flange With Spacing Of 2-7/8"
    Yes, the Demco Hydraulic Brake Kit - Free Backing - Galvanized part # 40716-15 will fit a 3,500 lb trailer axle with a brake mounting flange dimension of 2-7/8". The dimensions of the brake mounting flange from bolt hole to bolt hole is an industry standard, however some companies such as "Demco" refer to this measurement as a 2-3/4 instead of the more common 2-7/8". The actual dimension is really more like 2-13/16", but different brake manufacturers will round to either 2-3/4" or 2-7/8"....
    view full answer...
  • Brake Assembly Replacement Recommendation for 1994 Eagle Boat Trailer
    The brake assemblies part # 40716-15 that you referenced are exactly what you need. The size matches, the capacity is adequate, and the bolt pattern matches as well! I attached a review video for this brake assembly set for you to check out as well.
    view full answer...
  • How To Find the Axle Capacity of a Square Tube Axle To Determine Correct Braking Assemblies
    The process to measure the axle diameter to determine an approximate weight capacity does not apply to square tube axles. Therefore, you must find the axle tag if present and reach out to the axle manufacturer with the serial number if the capacity cannot be found on the axle tag. If the axle tag is not present then you will need to reach out to the trailer manufacturer. If the reason you need to determine the axle capacity is for choosing a set of braking assemblies then this is not needed....
    view full answer...
  • Ways to Determine Axle Capacity of Trailer
    There's a few ways to determine trailer axle capacity. You can check the axle for a label which will have it's capacity and length listed, it might be listed on the plate of the coupler that also has the VIN, or you can measure the diameter of the axle. If the axle diameter is 2-3/8 inches then that would indicate you have a 3,500 lb axle. If the drums of your hubs are 10 inch in diameter and 2-1/4 inches deep that would also indicate this too and would mean that the brake assembly set...
    view full answer...
  • What is Needed to add Brakes to Boat Trailer?
    To determine the brake assemblies that will fit your trailer, you would need to know your axle's weight capacity, the size of your wheels, your mounting flange bolt pattern and the inside diameter and depth of your hub. Depending on the type of brakes you want, different parts will be needed. For example, to add hydraulic drum brakes you would need a hydraulic drum brake actuator, a brake line kit and the brake assemblies. I've left a link to our page with our selection of brakes for you...
    view full answer...
  • Difference Between Demco 10 inch Drum Hydraulic Brakes and Brand Brakes
    The big differences is basically pricing and brands. The part # AKFBBRK-35-D is a pair of Dacromet coated drum, hydraulic brakes that are free-backing. The part # 40716-15 is essentially the same thing buy made by Demco. The etrailer brand is going to cost less since it's our brand and there's not as much markup so it's the better deal. Now the part # 40716-15 is basically just the part # 40716 and # 40715. What doesn't make much sense though is the pricing difference. It would seem to...
    view full answer...
  • Recommended Replacement 10 Inch Hydraulic Drum Brakes for 1985 EZ Loader Boat Trailer
    The Atwood Brake Actuator AT82543 referenced in your question is compatible with any trailer that has hydraulic drum brakes. Uni-servo wheel cylinders are found on certain hydraulic brake assemblies. If an assembly has them, this basically means that they are not free-backing assemblies, as they feature a single-pushrod wheel cylinder that will retain about 20 percent of their braking ability in reverse. If your trailer has a 3,500 pound axle, I recommend looking at the Demco Hydraulic...
    view full answer...
  • Can Mounting Studs be Removed from Hydraulic Brake Assemblies AKFBBRK-35-D
    The four mounting studs on Hydraulic Brake assemblies # AKFBBRK-35-D are not removable. These are press-fit for a permanent installation. For a similar brake without studs you can use Demco kit # 40716-15. These brakes are also free-backing galvanized finish left- and right-hand brakes for 3500-lbs axles.
    view full answer...
  • Center Hole Diameter & Brake Line Fitting For Demco Hydraulic Brake Kit 40716-15
    The center of the backing plate has a 2-3/8 inch diameter hole, and the brake line fitting is a 3/16" inverted flare for the Demco hydraulic brakes you asked about, which are the following part: - Demco Hydraulic Brake Kit - Free Backing - Galvanized # 40716-15 These brakes are rated for up to 3,500 lbs and the only other thing you will need with them is the mounting hardware, which is the Mounting Bolts and Hardware for 10" Brake Assemblies # BRKH10A.
    view full answer...
  • Hose Fitting Needed For Demco Hydraulic Brake Kit # 40716-15
    The Demco Hydraulic Brake Kit # 40716-15 uses a 3/16" Inverted Flare fitting to connect to the brake lines. If you need new mounting hardware for your brakes you can use the Redline Kit for 10" Brake Assemblies # BRKH10A .
    view full answer...
  • 3,500 lb Free-Back Hydraulic Brake Assembly Recommendation for Trailer
    For free backing, hydraulic drum brake assemblies that are 3,500 lb capacity we have assemblies that are 10 inch by 2-1/4 inch like the part # AKFBBRK-35-D which comes with assemblies for both sides of the trailer. We don't have anything that's 1-3/4 inch wide for a 3,500 lb axle.
    view full answer...
  • Availability of Replacement Brake Assemblies for Lippert 4,400 lb Trailer Axles
    The 4,400 lb trailer axle is an oddball when it comes to replacement parts but the easy solution is that you'd need 3,500 lb replacement assemblies like the part # AKEBRK-35-SA for a set of left and right hand assemblies that are self adjusting. While the assembly states that it was for a 3,500 lb trailer axle the great thing is that as long as the sizes and bolt pattern match up (like they do) they will work great. The only real difference between brake assembly capacities when the sizes...
    view full answer...
  • Correct Replacement Brake Shoes for a Demco Hydraulic Braking Kit
    Yes, the Replacement Brake Shoe Lining for Demco/Dico 10" Free-Backing Hydraulic Brakes # BP04-126 is the correct replacement brake shoes for your Demco Hydraulic Brake Kit # 40716-15.
    view full answer...
  • Replacement Brake Kit Options for Demco 40716-15 Brake Kit on a 2005 Karavan Boat Trailer
    The Demco brake kit 40716-15 that you say you have on your boat trailer is a direct match to this kit: - Demco Hydraulic Brake Kit # 40716-15 This is a free-backing kit though so it may be that your reverse lockout isn't necessarily needed if you're wanting to use these same exact brakes. For a duo-servo brake kit that matches the mounting bolt pattern you currently have you can use this kit instead: - Demco Hydraulic Brake Kit # DMSB18794M-93M The lockout feature has more to do...
    view full answer...
  • Are There Galvanized Trailer Hub/Drums for Travel Trailers
    We do have galvanized trailer hub/drums available for travel trailers. For example we have the part # 8-247-50UC3 which fits the very popular 3,500 lb trailer axles and has a 5 on 4-1/2 inch bolt pattern. If you have a different need for a hub/drum let me know and I'll see what we have that would be best option.
    view full answer...
  • Replacement Adjuster for Demco 3500lb 10 Inch Hydraulic Brake Assembly
    We do indeed, the # BP10-060 brake adjuster for 10 or 12 inch hydraulic brake assemblies fits Dexter, Demco and Dico 10" Hydraulic trailer brake assemblies, so it would work great for you. If you also need a new adjuster spring, use # 046-083-01
    view full answer...
  • Recommended Free Backing Hydraulic Brake Assembly for 3,500 lb Boat Trailer Axle
    For your Macgregor boat trailer with 3,500 lb axle, you will want the Demco Hydraulic Brake Kit - Free Backing - Galvanized - 10" - Left/Right Hand Assemblies - 3.5K # 40716-15. This galvanized assembly will work great for your boat trailer to resist corrosion and the free backing means you don't need a lockout to allow backing up without brakes applying. I've attached a video to assist.
    view full answer...
  • Replacement Brake Pads and Wheel Cylinder for 10 Inch Hydraulic Brake Assemblies on Boat Trailer
    Recommending replacement components like brake pads and a wheel cylinder for a hydraulic brake assembly without knowing who manufactured it would be very difficult. Are there any part numbers or manufacturer information on them? Without any manufacturer information, your best bet would be to simply replace the entire assembly. This way, you'll have all new parts and you'll know your brake assemblies will be good to go for a few years. For a boat trailer, I'd recommend using galvanized...
    view full answer...
  • Surge Coupler Equipped Trailer Brakes Occasionally Actuate When Backing Trailer
    When the brakes lock up, are you backing up a small hill or a rise? I'd be willing to bet you are. It sounds like your surge coupler isn't equipped with a reverse lockout. A reverse lockout will prevent the coupler from compressing and actuating the brakes when you back the trailer. There are a couple possible solutions for this. Depending on the surge coupler you have, it could be possible to install an electric lockout like part # T4748800 for Titan or Dico surge couplers or # DM11993...
    view full answer...

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Info for this part was:

Employee Mike L
Expert Research:
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Employee Jameson C
Expert Research:
Jameson C
Employee Adam R
Expert Research:
Adam R
Employee Lindsey S
Edited by:
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Employee Jeff D
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