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  1. Trailer Brakes
  2. Demco
  3. Hydraulic Drum Brakes
  4. 7000 lbs Axle
  5. 12 x 2 Inch Drum
  6. 14-1/2 Inch Wheel
  7. 15 Inch Wheel
  8. 16 Inch Wheel
Demco Hydraulic Brake Kit - Free Backing - Galvanized - 12" - Left/Right Hand Assemblies - 7K
Demco

Demco Hydraulic Brake Kit - Free Backing - Galvanized - 12" - Left/Right Hand Assemblies - 7K

Part Number: 42029-28
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$183.45
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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 14.5" to 16" wheels. Great Prices for the best trailer brakes from Demco. Demco Hydraulic Brake Kit - Free Backing - Galvanized - 12" - Left/Right Hand Assemblies - 7K part number 42029-28 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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Demco Trailer Brakes - 42029-28

  • Hydraulic Drum Brakes
  • 7000 lbs Axle
  • 12 x 2 Inch Drum
  • 14-1/2 Inch Wheel
  • 15 Inch Wheel
  • 16 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 14.5" to 16" wheels.


Features:

  • 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


Specs:

  • Dimensions: 12" diameter x 2" wide
  • Mounting flange bolt pattern: 5 bolt
  • Wheel size: 14-1/2", 15", and 16"
  • Axle rating: up to 7,000 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.



SB42029M Demco Galvanized 12" Marine Trailer Brake Assembly - Freebacking - Left Hand

SB42028M Demco Galvanized 12" Marine Trailer Brake Assembly - Freebacking - RightHand




California residents: click here


Video of Demco Hydraulic Brake Kit - Free Backing - Galvanized - 12" - Left/Right Hand Assemblies - 7K

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Comprehensive Review: Demco Hydraulic Brake Kit

Jeff: Hello, everybody. This is Jeff at etrailer.com. Today we're going to take a look at the Demco 12" x 2" left-hand and right-hand side galvanized hydraulic drum brake assemblies for up to 7,000-pound axles. Now, these are marine-grade hydraulic drum brake assemblies. They're great for boat trailers. They are designed for use with the surge type trailer brake actuators.

They are sturdy corrosion-resistant steel construction, and you can see they have the galvanized backing plates, which will work well for the marine applications. Also uses stainless steel spring hardware and up right up the top here a nice zinc-plated wheel cylinder.Now, these brake assemblies are a free-backing design, and the reason I say that is because the free-backing design will let you back up without engaging the trailer brakes even if your actuator is activated, and you can tell the free-backing design because one of these shoes looks like a D. You can see this shoe right here. This is a fall away shoe. This fall away brake shoe will only anchor on the drum when the brakes are engaged as the trailer's moving forward.

Because the shoe makes only a slight contact with the drum in reverse, just enough friction is generated so that only a minimal amount of braking occurs when you're in reverse. So, these brakes can be used when you're backing up. It just won't put full brake pressure on. It allows you to back up in reverse.Now, these are manual adjustment brakes, so you can see at the bottom here it has the adjustment wheel that you have to periodically manually adjust them. The mounting flange bolt pattern you can see is a five-bolt design.

Now, the mounting bolts to install these are not included. We do sell those separately on our website and they're listed on this product page as a related product. Configuration, it does include the left-hand driver's side and the right-hand passenger side. Now, when you get new brake assemblies, they'll always have a sticker on it that'll tell you what side is what. This one says R for right.

This would have L for left, but if the sticker wasn't on there and you wanted to know how to tell, the best way to tell what side the brake assembly is for is look at the length of the pad on the shoe.This pad goes from here to here. This pad goes from all the way to here to here. This is a longer pad. This is a shorter pad. The shorter pad is your primary shoe and the primary shoe will always face the front of the trailer. So, that's going to tell you this one will go this way, which is the right-hand passenger side. Same on this one, the pad length. This is the shorter one, so it's going to tell you that it's the left-hand driver's side.Now, again, the axles, these are designed for up to 7,000-pound axles. Now, the size on these are a 12" x 2", and what that means, the 12 inch is the diameter measured from here to here. So, if we put a ruler on it, there's your 12-inch diameter, and the two inch will be the width of the pad. So, there's your two-inch width. Now, these brake assemblies do require a 12-inch brake drum and the wheel size that'll fit on these is 14.5 inch- up to 16-inch diameter wheels. But that should do it for the review on the Demco 12" x 2" left-hand and right-hand side galvanized hydraulic drum brake assemblies for up to 7,000-pound axles.

Customer Satisfaction Score:


Customer Reviews

Demco Hydraulic Brake Kit - Free Backing - Galvanized - 12" - Left/Right Hand Assemblies - 7K - 42029-28

Average Customer Rating:  4.8 out of 5 stars   (18 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 14.5" to 16" wheels.

by:

I contacted your company to discuss replacing the discontinued brakes on my Trailmaster boat trailer and your Tech person was knowledgeable and accurate with his suggestions. Your website was great, and the videos you have available are perfect. I ordered that day, and I have never had better delivery. The Brake Kits I ordered look fantastic, and they installed very easy with no issues. Excellent product and Great informed people, I'll be back. Thank You. Keep up the great work.

Timothy profile picture

Timothy

8/25/2019

Excellent, Nice job, great business.



by:

Great product. Easy to install - MUCH easier than changing out individual components such as brake shoes. Don't cheap out by not getting the replacement mounting bolts. If your brake assemblies are bad enough to be replaced, so are the bolts (Ithink they should come with the brake assembly, not separately). This is the second time I have replaced the brake assemblies - no matter how good the galvanizing is, salt water eventually destroys them. Minimal adjustment needed after assembly with the hub.



by:

Older boat trailer had a wheel cylinder fail and fluid everywhere. These were easy to bolt on and a perfect replacement for what I had. This was not my first order from etrailer and I would recommend to anyone! Extremely fast shipping even when I just chose the regular, free method.

John profile picture

John

9/13/2019

No issues at all!



by:

This is a fantastic deal....makes the brake replacement easy and fast. Great quality. I will buy here again!



by:

Complete kit with the backing plate, 5 bolts and it's together. Easiest brake job I've ever done. Pics of brake kits make sure you have the right kit, and the ordering and shipping is FAST.



by:

Great service. Great prices. Timely responses via email and phone. Order was backordered by manufacturer and i was provided the appropriate alternative. Will be using e-trailer in the future.



by:

excellent, high quality



by:

Great fit. My 7000 lb boat has brakes again



by:

High quality parts sold at an excellent price. Highly recommend etrailer.



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by:

Excellent quality and fit.



by:

Advice in purchase was good and delivery was quick. Thanks



by:

Worked great thks



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See what our Experts say about this Demco Trailer Brakes

  • 12 inch Free Backing Hydraulic Brake Assembly
    Brake Assemblies like the Hydraulic Brake Kit - Uni-Servo - Free Backing - 12" - Left/Right Hand Assemblies - 5.5K to 7K item # AKFBBRK-7 will have the description in the title that the brakes are free backing. We also offer the same size free backing brakes in different finishes. Demco Hydraulic Brake Kit - Free Backing - Galvanized - 12" - Left/Right Hand Assemblies - 7K item # 42029-28. Hydraulic Brake Kit - Uni-Servo - Free Backing - Dacromet - 12" - Left/Right Hand - 5.2K to 7K...
    view full answer...

Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jeff D
Installed by:
Jeff D
Employee Wilson B
Updated by:
Wilson B
Employee Alexander C
Written by:
Alexander C

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