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Dexter Electric Trailer Brake Assembly - Self-Adjusting - 12-1/4" - Left Hand - 10,000 lbs

Dexter Electric Trailer Brake Assembly - Self-Adjusting - 12-1/4" - Left Hand - 10,000 lbs

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Dexter Axle Accessories and Parts - 23-438
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12-1/4" x 4" Driver's-side electric trailer brake assembly fits 10,000-lb axles. Mounting flange has 7-bolt pattern. Self-adjusting brakes require little maintenance. Fits 15" or larger wheels. Call 800-298-1624 to order Dexter Axle accessories and parts part number 23-438 or order online at Free expert support on all Dexter Axle products. Guaranteed Lowest Price and Fastest Shipping for Dexter Electric Trailer Brake Assembly - Self-Adjusting - 12-1/4" - Left Hand - 10,000 lbs. Accessories and Parts reviews from real customers.
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Dexter Axle Accessories and Parts

  • Trailer Brakes
  • Electric Drum Brakes
  • Brake Assembly
  • Dexter Axle
  • 12-1/4 x 4 Inch Drum
  • LH
  • Self Adjust
  • 10000 lbs

12-1/4" x 4" Driver's-side electric trailer brake assembly fits 10,000-lb axles. Mounting flange has 7-bolt pattern. Self-adjusting brakes require little maintenance. Fits 15" or larger wheels.


  • Electric brakes are easier to install and offer more user control than hydraulic brakes
    • Requires only an electric brake controller (sold separately) - no actuator or hydraulic lines necessary
  • Self-adjusting brakes automatically adjust to deliver optimum performance and braking power
    • No need for manual brake adjustments
    • Proper adjustment leads to better brake efficiency and less wear on your tow vehicle's brakes
  • Mounting bolts and hardware sold separately
  • Made in the USA


  • Application: most standard hub-and-drum assemblies, including Dexter and Lippert (LCI)
  • Configuration: left hand (driver's side)
  • Dimensions: 12-1/4" diameter x 4" wide
  • Mounting flange bolt pattern: 7 bolt
  • Wheel size: 15" or larger
  • Axle rating: up to 10,000 lbs
  • Limited 5-year warranty

K23-438-00 Dexter Electric Brake Assembly, LH 12-1/4" x 4" - Self Adjust - 10,000 lbs

Replaces 23-438

Item # 23-438

Customer Reviews

Dexter Electric Trailer Brake Assembly - Self-Adjusting - 12-1/4" - Left Hand - 10,000 lbs - 23-438

Average Customer Rating:  5.0 out of 5 stars   (1 Customer Reviews)

12-1/4" x 4" Driver's-side electric trailer brake assembly fits 10,000-lb axles. Mounting flange has 7-bolt pattern. Self-adjusting brakes require little maintenance. Fits 15" or larger wheels.

- 23-438

Website was very easy, (with no attitude from the no nothing parts man) received order in 2 days and for less money than locally.


Ask the Experts about this Dexter Axle Accessories and Parts

  • Will Dexter 12-1/4 x 4-Inch Left-Hand Electric Brake # 23-438 Fir 10K Dexter Axle D1012
    The brake assembly you referenced, Dexter 12-1/4 x 4-Inch Left-Hand Electric Brake # 23-438, is indeed rated for 10K axles. This brake matches up to Right-Hand brake # 23-439. You can check for fit on your existing axle's brake flanges by checking the mounting bolt pattern. Both of these brakes use a 7-bolt mounting pattern. As long as your drums are 12-1/4 x 4-inches and your brake flanges use the 7-bolt mounting pattern these will work great as replacements.
    view full answer...
  • Servicing Electric Trailer Brakes on a Tandem Axle Trailer with 10,000 Pound Axles
    I have included 3 videos that will help you. One specifically is on installing electric brakes. The trailer in that video did not start with brakes so it will be a little different. However it will still show you how to remove the hub and adjusting the brakes. I have all included a video just on installing a hub. And finally I have included a video on bearings that should be very helpful. Some tips that I will add is to make sure that you clean off all of the old grease and use new grease...
    view full answer...
  • Parts Needed to Replace Grease Lube Hubs with Oil Bath Hubs
    You will not need to replace the brakes on your trailer when converting from grease lube hubs to oil bath hubs. The oil bath hubs that you choose should come with the proper bearings, seal and oil cap for that hub. You will want to check the part numbers on your bearings and seals to ensure you select the correct hubs for your spindles. We carry two oil bath hub and drum assemblies. Trailer Hub and Drum Assembly, # 8-219-9UC3-A, fits 5,200 lb to 7,000 lb axles with spindles that require...
    view full answer...
  • How to Tell if Trailer Drum Brake Assemblies are On the Right Side
    If you pull of the hubs on your trailer you should see the actuating arm holding the magnet below the spindle. If you imagine the arm as the end of an arrow it should be pointing towards the front of the trailer. If yours are on the wrong sides they would perform like you described.
    view full answer...
  • How to Determine if a Hub Was Originally Designed as an Oil Bath or Grease Hub
    An easy way to tell if your hubs were originally oil filled or packed with grease is to remove the cap of the hub. Typically, if it is a press-in cap it is a grease hub, and if it is a screw-in cap it is an oil bath hub. Not only do semi trailers use oil bath hubs, there are many heavy duty trailers that will use them as well. If you have been putting grease in your hub so far and it has been working well for you, then I would just stay with the grease. I attached an FAQ article on...
    view full answer...
  • Two Year Old Big Horn 3670RL 5th Wheel Trailer Leaking Grease into All Four Brake Assemblies.
    If all four wheels on your 2-year-old Big Horn 5th wheel trailer have suddenly leaked wheel bearing grease into the brake assemblies my initial thought is that perhaps the bearings have recently been re-packed (which is typically to be done at 6 or 12 month intervals depending on manufacturer) with either too much grease or with grease of an incorrect grade. While there are general-purpose grease products that can be used in multiple applications, wheel bearings usually require a grease...
    view full answer...
  • Width of Brake Pads on 28 Foot Gooseneck Trailer With Dexter 10K Axles
    To determine which brake assembly you need, measure the width of your brake linings, as shown in the photo I edited for you. If your existing brake shoes measure 4 inches wide, the # 23-438 you mentioned would be an example of a good replacement for you if your existing brake assemblies use 7 mounting bolts (some use 4) and the diameter of the assembly is 12-1/4 inches in diameter when measured from the outside of one brake shoe directly across to the outside of the other shoe as shown...
    view full answer...
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  • Electric Brake Assembly For Tandem 10k Dexter Axles
    For your tandem Dexter 10,000 pound axles, you will want to use the Dexter Electric Trailer Brake Assembly # 23-438 for the left hand assembly, and the Dexter Electric Trailer Brake Assembly # 23-439 for the right hand assembly. These are self adjusting brakes that require little maintenance.
    view full answer...
  • Trailer Brake Magnets for Dexter 10k Axles
    Not all trailer brake magnets are the same, but since we know you have a Dexter 10,000 lb trailer axle the correct magnets would be the part # BP01-301 which would be correct for the brake assemblies # 23-438 and # 23-439.
    view full answer...
  • Replacement 12-1/4 x 4 Inch Brakes for 10,000 Pound Dexter Trailer Axles
    If your drums are 4 inches wide where the brake shoe pad makes contact with the inside of the drum then you will need 12-1/4 by 4 inch brakes # 23-438 for the left and # 23-439 for the right. If you are measuring the overall depth of the drum then you likely need the 12-1/4 by 3-3/8 assemblies such as # AKEBRK-10L which would fit on Dexter axles.
    view full answer...
  • Adjusting Dexter 10K Electric Trailer Brakes
    The Dexter 10K electric brakes # 23-439 (right side) and # 23-438 (left side) will have to be manually adjusted using the adjustment wheel below the magnet. To adjust the brakes you will use a small screwdriver or similar tool to turn the adjustment wheel. The wheel pushes out the shoes. You will keep turning the wheel until the pads lightly, but consistently, drag on the drum. The brakes should be adjusted like this anytime you notice braking starting to weaken. I have included a link...
    view full answer...
  • How To Adjust And Test Electric Brakes On A Trailer
    It sounds like you need to adjust the brake on your trailer. If you have electric brakes like the Dexter Electric Brake Assembly LH, part # 23-438, you can make the adjustments pretty easily. I have attached a video that shows trailer brakes being installed. If you go to about the 4:40 mark on the video it shows how to adjust the brakes. I have also attached a photo of an electric brake that shows where the adjustment wheel is located. You can also test the magnet on the brake that...
    view full answer...
    Image 1 for
  • Replacement Electric Drum Trailer Brakes for a 10,000 Pound Wells Cargo Trailer
    The brakes on your Wells Cargo trailer could just be in need of adjustment. On drum brakes you will adjust the brakes so that there is a slight but constant drag of the pads on the drum when you turn the wheel. To see how to manually adjust trailer brake assemblies check out the video I attached, fast-forward to the 4:35 mark of the video. If the trailer has 2 axles then you likely have de-rated 6K axles (5200 pound axles). This size would be 12x2 inches. they mount to a 5-hole mounting...
    view full answer...
    Image 1 for
  • Bearings, Seal, & Electric Brakes For Big Tex 22GN 35+5 Gooseneck Trailer
    I was able to find the correct electric brakes, as well as oil seal (which is what I assume you were referring to by wheel seal), and also the bearings for your Big Tex 22GN 35+5 gooseneck trailer. I'll go ahead and list out the parts for you below. - Oil Seal # 10-56 - Replacement Trailer Hub Bearing # 395S & Race # 394A - Replacement Trailer Hub Bearing # 387A & Race # 382A - Dexter Electric Trailer Brake Assembly - Left Hand # 23-438 & Right Hand # 23-439
    view full answer...

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