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Dexter Hydraulic Drum Brake Assembly - Uni-Servo - 10" - Left Hand - 3,500 lbs

Dexter Hydraulic Drum Brake Assembly - Uni-Servo - 10" - Left Hand - 3,500 lbs

Item # 23-312
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Accessories and Parts 23-312 - 10 x 2-1/4 Inch Drum - Dexter
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10" x 2-1/4" Driver's-side hydraulic trailer brake assembly features a single-plunger design. Mounting flange has a 4-bolt pattern. Fits 13" to 15" wheels. 1-800-940-8924 to order Dexter accessories and parts part number 23-312 or order online at Free expert support on all Dexter products. Great prices and Fastest Shipping for Dexter Hydraulic Drum Brake Assembly - Uni-Servo - 10" - Left Hand - 3,500 lbs. Accessories and Parts reviews from real customers.
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  • Reviews (10)
  • Q & A (0)
  • Videos (1)
  • Photos
  • Why etrailer?

Dexter Accessories and Parts - 23-312

  • Trailer Brakes
  • Hydraulic Drum Brakes
  • Brake Assembly
  • 10 x 2-1/4 Inch Drum
  • Dexter
  • LH
  • Single Servo
  • 3500 lbs

10" x 2-1/4" Driver's-side hydraulic trailer brake assembly features a single-plunger design. Mounting flange has a 4-bolt pattern. Fits 13" to 15" wheels.


  • Hydraulic drum brake assembly is designed for use with a surge-type trailer brake actuator
  • Periodic manual adjustment required
  • Adjuster plugs (included) cover access holes to keep dirt and grime out of the assemblies and off of the shoes
  • Mounting hardware included
  • Made in the USA


  • Configuration: left hand (driver's side)
  • Dimensions: 10" diameter x 2-1/4" wide
  • Mounting flange: 4 bolt
  • Wheel size: 13", 14", and 15"
  • Axle rating: up to 3,500 lbs

K23-312-00 Dexter 10" Single-Servo Hydraulic Brake Assembly - LH - 3.5K

Replaces 23-312

Video of Dexter Hydraulic Drum Brake Assembly - Uni-Servo - 10" - Left Hand - 3,500 lbs

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

Video Transcript for Dexter Axle Trailer Brakes 23-312 Review

Customer Satisfaction Score:

Customer Reviews

Dexter Hydraulic Drum Brake Assembly - Uni-Servo - 10" - Left Hand - 3,500 lbs - 23-312

Average Customer Rating:  4.9 out of 5 stars   (10 Customer Reviews)

10" x 2-1/4" Driver's-side hydraulic trailer brake assembly features a single-plunger design. Mounting flange has a 4-bolt pattern. Fits 13" to 15" wheels.


Exact replacement for my old ones at a great price with prompt shipping. Still letting the penetrant seep into the hose end connections before removal. Since the backing plate is coming off, I plan on leaving the hoses attached to the cylinders so they can be exchanged on the bench. The only hose connections on vehicle will at the hard line where there is more room to work.


My tow dolly brakes failed while on the road this summer. Found WiFi and it was a snap to order the parts thanks to an excellent online ordering system. Thanks!!


Sticker says Made in USA. Fits like a glove.My brakes were rusted and just to old to not want something new I can count on. etrailer helped me size it out by providing bolt to bolt measurements. The first assembly I was ordering would not have fit because I ordered without accurately measuring what I was working with. I will now have a safe boat towing experience downhill as a result. Thank You etrailer and Thank You Judy!


Great ! Bolted right on in about 10 min! Nice new parts! Won't have to worry about my trailer brakes for years now!! Wish I knew about eTrailer years ago!!


Brake assembly was an exact fit. It was easy to remove the old assembly & install the new. Made the whole job very easy. Good price compared to other sites.


Easiest brake job ever. Great video to install the unit.



Great U.S. Made product. Works like a c harm.




See what our Experts say about this Dexter Accessories and Parts

  • Troubleshooting Hydraulic Trailer Brakes Locking Up on One Side
    If the brakes have been bled properly and your drums were replaced then the problem may be your wheel cylinder (see attached picture). Sometimes those can get worn out and then that pin will sit at an angle and prevent the piston from retracting. You did say that your backing plate was replaced. I am not sure if you meant the whole brake assembly, like part # 23-312, or if you had just the backing plate replaced. Typically the whole brake assembly is replaced as opposed to just the baking...
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  • What Brake Flange Bolt Pattern Do the Dexter Hydraulic Drum Brake Assembly 3,500 Lbs Fit
    The Dexter Hydraulic Drum Brake Assembly part # 23-313 for right hand and part # 23-312 for left hand uses an industry standard brake mounting flange pattern which I have attached a photo of below. I would bet this is what you have as you are very close and it's not uncommon for there to be a 1/8" - 1/4" discrepancy since measuring the center of the hole is not always easy.
    view full answer...
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  • Replacement Dexter Hydraulic Brake Assemblies for 023-344-00 and 023-345-00
    For your replacement Dexter hydraulic brake assemblies, you will want the Dexter Hydraulic Trailer Brake Kit - Uni-Servo - 10" - Left and Right Hand Assemblies # 23-312-313. These will work very well with your existing hub/drum assemblies.
    view full answer...
  • Troubleshooting Hydraulic Drum Brakes on Boat Trailer Rubbing After Removing Actuator
    With your boat trailer, removing the actuator would not have caused the brakes to apply. It sounds like there is a mis-adjustment with the assembly due to either the springs or adjuster spacer not engaging correctly. I assume the lack of pressure in the wheel cylinder likely meant shifting of the brake shoes and causing misalignment. I recommend removing the hub and then removing the brake shoes, springs, and adjuster. This will remove any braking issues causing rubbing/grinding. I...
    view full answer...
  • Parts Needed to Add Trailer Brakes to a Coleman Redwood Pop-Up Camper
    The first step is to determine what size drum hub you need. You will first measure the bolt pattern of the lugs on your current hubs. I have included a link to a page that will show you how to measure this. If you give me the part number of the hubs, I could probably find out the bearing and seal numbers. You could also pull the hubs apart and get the bearing and seal numbers off of the old ones. I will include a video link about replacing bearings and seals. You will need to do this anyway...
    view full answer...
  • Compatibility of Hydraulic Brake Assemblies on UPF Axles
    The Hydraulic Trailer Brake Kit - Uni-Servo - 10" - Left and Right Hand Assemblies - 3,500 lbs # AKUBRK-35 will work the same as the Dexter Hydraulic Trailer Brake Kit - Uni-Servo - 10" - Left and Right Hand Assemblies - 3.5K # 23-312-313. The difference is mainly in the name brand. Either assembly will work fine on your tandem UPF axles.
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  • Are Dexter Hydraulic Trailer Brakes # 23-312-313 Free Backing
    The Dexter Hydraulic Trailer Brake Kit # 23-312-313 that you referenced are standard uni-servo assemblies and are not free-backing. These will not automatically disengage when going in reverse with the trailer. For 3,500 pound free-backing assemblies I instead recommend the Hydraulic Trailer Brake Kit # AKFBBRK-35. This kit includes both the left and right hand assemblies and they use automotive-grade friction material that's molded to the shoe. I have attached a short...
    view full answer...
  • Replacement Master Cylinder Kit for Dico Model 60 Coupler/Actuator and 10" Dexter Drum Assemblies
    We had a customer install the Titan Model 60 master cylinder kit part # T4395100 on their Dico model 60 and although the bore was a little bigger they were able to make it fit. Then for Dexter 10 inch brake assemblies we have the part # 23-312-313 for a pair of left and right hand assemblies.
    view full answer...
  • Replacement Hub/Drums & Brakes to Replace AL-KO 7230 Hubs
    You can select your new hubs by matching up your axle weight rating, wheel bolt pattern and the bearings used in your current hubs. Based on my research your hubs are 10 x 2-1/4-inches, are from a 3500-lb axle and have the 5-on-4-1/2 bolt pattern. If they use inner bearing L68149 and outer bearing L44649 then you can use Dexter hub/drum # 84546UC3. If you have other bearings you can use the linked page to select your axle rating, bolt pattern, bearings to find a matching hub. For brakes...
    view full answer...
  • 3500lb Axle Hydraulic Brake Assembly with Drum, Bearings and Seals
    Dexter Hydraulic Drum Brake Assembly - Uni-Servo - 10" - Left Hand # 23-312 would be the closet thing we have but it does not have the parking brake. For the Drum Assembly # AKHD-545-35-K is what I recommend giving the following is correct. It does not have EZ lube spindles, you have a 5 on 4-1/2" wheel bolt pattern (see link below for how to measure) and the same bearing Inner bearing: L68149 (1.378" inner diameter) Outer bearing: L44649 (1.063" inner diameter) and seal Inner diameter:...
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  • Recommendation for Corrosion Resistant 10 x 2-1/4 Hydraulic Trailer Brake Assemblies
    The hydraulic drum brakes that are good for marine applications are going to be the galvanized models like # 40716 as an example. Others, like the Galphorite coated assemblies, like # T4423400, also offer excellent corrosion resistance. Any assembly that does not have a special coating and/or is not galvanized then that would indicated it is powder coated steel, like # 23-312, and is not ideal for marine applications. If you are looking for 10 x 2-1/4 assemblies for marine applications,...
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  • Wheel Cylinder Needed for 10 Inch Dexter Hydraulic Brake Drum Assembly
    Based on my research, the 36-94 backing plate is used on the Dexter Single Servo # 23-313, # 23-312 hydraulic brake assemblies. For a 10 inch brake, left hand side, you will want # BP17-030 Wheel Cylinder. For 10 inch brake, right hand side, you will want # BP17-020 Wheel Cylinder.
    view full answer...
  • Can the Duo-Servo Demco Hydraulic Brake Kit Replace a Uni-Servo Dexter Hydraulic Trailer Brake Kit
    The Duo-Servo Demco Hydraulic Brake Kit # DMSB18794M-93M fits 10" hub and drum assemblies as well as the same mounting hole dimensions as the Uni-Servo Dexter Hydraulic Trailer Brake Kit # 23-312-313. This means that you definitely can replace them with the Duo-Servo kit. The Demco Duo-Servo kit is perfect if you have a boat trailer. The galvanized backing plates, stainless steel spring hardware, zinc-plated wheel cylinders will do a much better job at ressisting rust and corrosion from...
    view full answer...
  • 3,500 lb Capacity Hub/Drum and Brake Assembly Recommendation for 2004 Karavan with 3,500 lb Axle
    For a replacement Dexter 3,500 hub and drum for your 2004 Karavan Boat Trailer you would want the part # 84546UC3-EZ. This hub has the same 5 on 4-1/2 inch bolt mounting flange as what you most likely currently have and has a 3,500 lb capacity. If you have a different bolt pattern check out the link I attached to see all the hubs that would fit the same spindle. I also attached a link to an article on determining wheel bolt patterns as well. Then for brake assemblies you would want the...
    view full answer...
  • Trailer Brake Solution for 3,500 lb Axles for Saltwater Use
    We have galvanized hub/drums that are a fit for 3,500 lb axles like the part # 8-247-50UC3-EZ which would work well. For compatible brake assemblies use # 23-312 for the left and # 23-313 for the right if your brakes are hydraulic or part number # AKEBRK-35-SA for if they are electric.
    view full answer...
  • Replacement Trailer Hub Recommendation for Bearing Race Numbers L44610 Inner/Outer
    Sounds like you have an EZ lube spindle like the part # TRU74FR. We don't carry any type of sleeve for this type of spindle. Are you talking about a washer for the castle nut possibly? The part # L44610 is actually a race for # L44649 bearing and since you said you have two of them that would indicate you have a 3,500 lb axle hub. The part # 84546UC3 is a 3,500 lb hub like you'd need then. The uni-servo assemblies part # 23-313 and # 23-312 would work well with this.
    view full answer...
  • Replacement Brakes for Unknown Dexter Axle on 1987 Fleetwood 5th Wheel Trailer
    For your braking assembly you will simply need to measure your hub diameter or the backing plate on your brake assembly and the thickness of your hubs. You will either need the Dexter Electric Trailer Brake Kit - 10" - Left and Right Hand Assemblies - 3,000 lbs # K23-472-473-00 that are 10 x 1-1/2 inches or the wider brake shoe assemblies # 23-468-469 that are 10 x 2-1/4 inches. If you have 7 inch assemblies, you will want # K23-103-104-00. If you have hydraulic brakes, you will either...
    view full answer...
  • Installing Hydraulic Trailer Brakes on a Kristi Utility Trailer
    There are two ways to go. Drum brakes and Disc brakes. To determine which assemblies will fit on your spindles we will need to know the inner and outer bearing and seal part numbers. We will also need the Brake Mounting Flange bolt pattern on the spindles and the bolt pattern and size of the wheels that are on your trailer. For the hydraulic actuator we will need the size of the trailer tongue where the actuator will mount. If you will get back to me with your choices and the needed information...
    view full answer...
  • Recommended Brakes/Actuator That Allow Single Axle Boat Trailer to Be Pushed in Reverse by Hand
    The Dexter Brake Actuator part # T63FR which is for drum brakes has a manual lockout which means you can engage this at the coupler with a pin and this will then allow for reversing the trailer without free backing braking assemblies. This is done instantly and there should be no take-up to get the trailer to reverse like there is for free backing braking assemblies. The Dexter Brake Actuator would then pair nicely with the Dexter Hydraulic Trailer Brake Kit part # 23-312-313 and Dexter...
    view full answer...
  • Can Timbren Axle-Less Suspension be Used for a Boat Trailer/Marine Applications
    You can use Timbren Axle-Less suspension for marine applications. But you would need 3500 pound kit # ASR3500S05. If attaching brakes you would need hydraulic brakes and not electric brakes. For a hub and drum assembly you could use # 8-247-50UC3-EZ which is a galvanized model for corrosion resistance. It has a 5 on 4-1/2 bolt pattern For compatible brake assemblies use # 23-312 for the left and # 23-313 for the right. Then you would need a brake actuating coupler, see link to the right...
    view full answer...
  • What is Needed to Replace Hydraulic Drum Brakes with Disc Brakes?
    You can definitely replace your current brakes with a disk brake set up. However, there are a few things that will need to be checked and upgraded to accomplish this task. First, you will need to determine which inner and outer bearings fit your spindle. As an example, the Kodiak Disc Brake Kit - 10" Hub/Rotor - 5 on 4-1/2 - Dacromet - 3,500 lbs # K2HR35D is designed to fit spindles with an # L68149 inner bearing and # L44649 outer bearing on a 3,500 pound axle. This will also use a 5...
    view full answer...
  • Which Hydraulic Brakes Fit the Timbren Heavy-Duty Axle-Less Trailer Suspension
    The Timbren Heavy-Duty Axle-Less Trailer Suspension # ASR35HDS02 can be used with hydraulic brakes but they will not work with the Dexter # 23-312-313. The Timbren system is designed to be used with the Dexter Trailer Hub and Drum Assembly # 8-201-9UC3-EZ and has a 5 bolt brake flange configuration. For hydraulic brakes that will fit, I recommend the Hydraulic Trailer Brake - Uni-Servo - 12" # AKUBRK-7R and # AKUBRK-7L. These hydraulic drum brakes are 12" x 2" and also have the same 5...
    view full answer...

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Info for this part was:

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Updated by:
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Employee Alexander C
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Employee Robert G
Expert Research:
Robert G
Employee Michael H
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Michael H
Employee Jeff D
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