1. Accessories and Parts
  2. Redline
  3. Trailer Brakes
  4. Electric Drum Brakes
  5. Brake Assembly
  6. 12-1/4 x 3-1/2 Inch Drum
Electric Brake Assembly - 12-1/4" x 3-1/2" - Left Hand

Electric Brake Assembly - 12-1/4" x 3-1/2" - Left Hand

Item # 10257
lowest price pledge
Our Price: $325.08
You Save: $40.72
Accessories and Parts
This item qualifies for Free Shipping
Shipping Weight: 21 lbs
In Stock
Redline Brake Assembly Accessories and Parts - 10257
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

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


Call 800-298-8924 to order Redline accessories and parts part number 10257 or order online at etrailer.com. Free expert support on all Redline products. Guaranteed Lowest Price and Fastest Shipping for Electric Brake Assembly - 12-1/4" x 3-1/2" - Left Hand. Accessories and Parts reviews from real customers.
  • All Info
  • Reviews (2)
  • Q & A (7)
  • Videos (1)
  • Photos
  • Why etrailer?

Redline Accessories and Parts - 10257

  • Trailer Brakes
  • Electric Drum Brakes
  • Redline
  • Brake Assembly
  • 12-1/4 x 3-1/2 Inch Drum
  • LH
  • Self Adjust
  • 12000 lbs


  • Hayes/AL-KO 12-1/4" x 3-1/2" electric brake assembly - left hand
  • Capacity: 12,000 lbs per pair
  • Fits: 9K through 12K axles
  • Mounting flange bolt pattern: 5 bolt
  • Mounting studs included

K23-528-00 Electric Brake Assembly - 12-1/4" x 3-1/2" - Left Hand

Replaces 186700 and K568255.2

Video of Electric Brake Assembly - 12-1/4" x 3-1/2" - Left Hand

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

Video Transcript for Redline Trailer Brakes 10257 Review

Today we're going to take a look at the Hayes AL-KO 12-and-a-quarter-inch by 3-and-a-half-inch driver's side electric brake assembly for 9,000 lbs. to 12,000 lbs. axles. Now electric brakes are easier to install. They offer more user control than hydraulic brakes. They do require only an electric brake controller to use them.

There is no actuator hydraulic lines necessary. Now the size on this one is 12-and-a-quarter by 3-and-a-half inches. It's the driver's side electric brake assembly, and when they do the size, the 12-and-a-quarter by 3-and-a-half, what they're measuring, the 12-and-a-quarter would be measured from this pad all the way across to this pad. If I put a ruler edge to edge, there's your 12-and-a-quarter, and the 3-and-a-half would be the width of the pad. So again if you put the ruler on here, there's your 3-and-a-half inches, and this is the left hand driver's side. And a good way to tell on this assembly, I mean on a new assembly, it'll have a sticker which will tell you. But if that sticker wasn't there, the way to determine what side this goes on is your magnet will always be at the bottom of the brake assembly and this actuating arm will always face the front of the trailer.

So if we know this is at the bottom, and this is towards the front, then this will show that this is the left hand or driver's side assembly. Now the pads on this, they do use a friction material which is fully bonded. It's not riveted to the shoes. Gives you a lot longer life and more braking torque. The other nice thing on each end, you can see right here they actually chamfer or taper this edge to prevent cracking and crumbling that can lead to mechanical lock-up. Now this is a self-adjusting brake, and the way you can tell that, is this cable that goes around this holder right here and connects to a lever on the adjustment wheel. That's a self-adjusting cable.

So a self-adjusting brake does not require periodic manual adjustment like standard brakes. Basically on this after you install it you make your initial adjustment, and then from then on it will self-adjust as you go. I flip it over to the back here, you can see this fits a five bolt brake mounting flange. Now the mounting bolts and the nuts are all included to install this. This assembly is certified by U.S. SAE standards, and again just the specs on it, it's a 12-and-a-quarter-inch by 3-and-a-half-inch dimension.

It fits axles from 9,000 lbs. up to 12,000 lbs. Again, it's the left hand driver's side. It does require the use of 12-and-a-quarter-inch brake drums, and it is an electric brake, so you do need to make an electric connection. The two wires back here, you can see two red wires. One needs to go to the brake feed, one goes to the ground, and they're both red wires so either one can go for either function. But that should do it for the review on the Hayes AL-KO 12-and-a-quarter by 3-and-a-half inch driver's side electric brake assembly for 9,000 lbs. to 12,000 lbs. axles.

Customer Reviews

Electric Brake Assembly - 12-1/4" x 3-1/2" - Left Hand - 10257

Average Customer Rating:  5.0 out of 5 stars   (2 Customer Reviews)

- 10257

Great quality 424335

- 10257

product was not to be found locally, and when found at etrailer it was delivered quickly. 286517


Ask the Experts about this Redline Accessories and Parts

  • Why etrailer.com?

    At etrailer.com we guarantee:
  • Highest quality accessories and parts for the best price.

    Our Lowest Price Pledge ensures you will never overpay for the parts you need.
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate accessories and part information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Installed by:
Jeff D
Expert Research:
Jameson C
Updated by:
Laura H
Updated by:
Sarah W
Updated by:
Mike S

At etrailer.com 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.