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  1. Trailer Brakes
  2. Dexter
  3. Disc Brakes
  4. 6000 lbs Axle
  5. Hub and Rotor
  6. 15 Inch Wheel
  7. 16 Inch Wheel
  8. 16-1/2 Inch Wheel
Dexter Disc Brake Kit - 12" Hub/Rotor - 6 on 5-1/2 - E-Coat - 6,000 lbs

Dexter Disc Brake Kit - 12" Hub/Rotor - 6 on 5-1/2 - E-Coat - 6,000 lbs

Item # K71-638-639
Our Price: $1,647.99
Trailer Brakes
This item qualifies for Free Shipping
Shipping Weight: 111 lbs
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Two brakes fit 6,000-lb E-Z Lube axles with 15" to 16-1/2" wheels. E-coat finish on hubs, rotors, calipers, and brackets resists corrosion. Inner bearings (25580), outer bearings (15123), races, grease seals, and grease caps included. Great Prices for the best trailer brakes from Dexter. Dexter Disc Brake Kit - 12" Hub/Rotor - 6 on 5-1/2 - E-Coat - 6,000 lbs part number K71-638-639 can be ordered online at or call 1-800-940-8924 for expert service.
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Dexter Trailer Brakes - K71-638-639

  • Disc Brakes
  • 6000 lbs Axle
  • Hub and Rotor
  • 15 Inch Wheel
  • 16 Inch Wheel
  • 16-1/2 Inch Wheel
  • Camper
  • Car Hauler
  • Utility Trailer
  • 6 on 5-1/2
  • Dexter
  • 1/2 Inch Studs

Two brakes fit 6,000-lb E-Z Lube axles with 15" to 16-1/2" wheels. E-coat finish on hubs, rotors, calipers, and brackets resists corrosion. Inner bearings (25580), outer bearings (15123), races, grease seals, and grease caps included.


  • Trailer brake assemblies make it easy to upgrade from drum brakes to disc brakes for better performance
    • More consistent stopping, even at highway speeds
    • Dramatically shorter stopping distance
    • Easier and less expensive to maintain
  • E-coat finish provides corrosion resistance for freshwater and limited saltwater use
  • Vented rotors help to regulate temperature to prevent overheating
  • Included hubs replace your existing hubs
  • Self-adjusting calipers ensure maximum surface contact for smooth, equal braking
  • Semi-metallic brake pads resist heat and provide excellent grip
  • Grease caps feature removable plugs for easy access to grease zerks on E-Z Lube axle
  • Ductile iron mounting brackets provide strength and durability
    • Weld-on flanges sold separately
  • Kit includes 2 full brake assemblies for 1 axle
    • 2 E-coated rotors
    • 2 E-coated hubs with bolts pressed in
    • 2 E-coated ductile iron calipers
    • 4 Semi-metallic brake pads
    • 2 E-coated caliper mounting brackets with bolts and nuts
    • Bearings, races, grease seals, and E-Z Lube grease caps
    • Thread sealant
  • Hydraulic brake actuator and lines (sold separately) are required for brakes to be activated
    • Requires psi rating of at least 1,600
  • Made in the USA


  • Fits:
    • Axle capacity: 6,000 lbs
    • Wheel size: 15", 16", and 16-1/2"
  • Bolt pattern: 6 on 5-1/2"
  • Wheel bolt diameter: 1/2"
  • Rotor diameter: 12"
  • Brake flange configuration: 5 bolt
  • 5-Year limited warranty

Bearing, Race, and Seal Information

  • Bearings (included)
    • Inner bearing: 25580 (1.75" inner diameter)
    • Outer bearing: 15123 (1.25" inner diameter)
  • Races (included)
    • Inner race: 25520
    • Outer race: 15245
  • Grease seal (included): GS-2250DL
    • Inner diameter: 2.25"
    • Outer diameter: 3.376"

K71-638-00 Dexter Axle Disc Brake Assembly - 12" Hub/Rotor - 6 on 5-1/2 - E-Coat - 6,000 lbs - Left Hand

K71-639-00 Dexter Axle Disc Brake Assembly - 12" Hub/Rotor - 6 on 5-1/2 - E-Coat - 6,000 lbs - Right Hand

Video of Dexter Disc Brake Kit - 12" Hub/Rotor - 6 on 5-1/2 - E-Coat - 6,000 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 - Disc Brakes - K71-638-639 Review

Speaker 1: Today, we're gonna take a look at the Dexter E-Coat Disc Brake Kit, 12" Rotor and Hub with the 6 on 5 1/2" Bolt Pattern for 6000 Pound Axles. Now, this trailer brake assembly will make it easy to upgrade from your drum brakes to your disc brakes for better performance. Gives you more consistent stopping even at highway speeds and dramatically shorter stopping distance, and it is easier and less expensive to maintain.All these parts have a nice E-Coat finish to them to provide corrosion resistance for freshwater and limited salt water use. Now, this kit will include everything shown here on the table. It is two full brake assemblies for one axles. Comes with the two E-Coated rotors, the two E-Coated hubs with the bolt's studs already pressed in, the two E-Coated ductile iron calipers with the four semi-metallic brake pads, also the two E-Coated caliper mounting brackets with the bolts and nuts to install it, and if you notice all the bearings and the hardware to install everything is also included.Now, the rotors on this, they are a vented rotor which will help regulate temperature, prevent overheating.

It'll dissipate the heat. Also included are these hubs which will replace your existing hubs, and the calipers are a self-adjusting caliper to ensure maximum surface control for nice, smooth, equal braking. They do include the semi-metallic brake pads to help resist heat and provide excellent grip.The mounting brackets that they install to, they are also a ductile iron mounting bracket. Prevents strength and durability. Again, all the hardware's included.

Also what's nice is the grease caps they give you are easy lube grease caps which feature the removable center rubber plugs, so when these are installed, you can just pop out that rubber plug, gain access to the grease zerk fitting that's on the end of an easy lube back, so pump your grease in there and there's no need to remove the hubs.Now, this kit does require a hydraulic brake actuator and brake lines that are to install these to activate the brakes, and those are sold separately on our website, and they're usually listed on this product page as a related product. You do want to make sure when you do get the actuator or the brake lines that they do have to have at least a 1600 PSI rating. These parts are made in the USA.Again, they are designed to fit axle capacity of 6000 pounds. The wheel size that'll work on these hubs are 15", 16", and 16 1/2". The bolt pattern is 6 on 5 1/2" bolt pattern.

The wheel bolt or wheel lug diameter is half an inch the rotor diameter is a 12" rotor diameter. On the mounting brackets, they are a five bolt brake flange configuration, and then all the bearings, races, and seals are all included, all laid out here. The bearings, which are included, you have your inner bearing which is the larger bearing. That's part number 25580, has a 1.75 inner diameter. The outer bearing, which is a smaller, is part number 15123, has a 1.25" inner diameter.Now, the bearing races, they already pre-install them onto the hub.

The grease seals, they are a part number GS-2250DL. They are a double lip grease seal, have an inner diameter of 2.25" and an outer diameter of 3.376". That should do it for the review on the Dexter E-Coat Disc Brake Kit, 12" Rotor and Hub with the 6 on 5 1/2" Bolt Pattern for 6000 Pound Axles.


See what our Experts say about this Dexter Trailer Brakes

  • Fit of Dexter Disc Brake Kit for 6,000 lb Axles with Torsion Axle
    The Dexter Disc Brake Kit - 12" Hub/Rotor - 6 on 5-1/2 - E-Coat - 6,000 lbs # K71-638-639 is compatible with certain straight and torsion axle trailers. It simply requires a 5 bolt brake flange and spindles with a 1.75 inch inner bearing diameter as well as a 1.25 inch outer bearing diameter. This is common on a Dexter 6,000 lb capacity axles whether straight or torsion. This kit is compatible with 15, 16, and 16-1/2 inch wheels only that have the 6 on 5-1/2 inch bolt pattern. If you...
    view full answer...
  • Recommended Hubs and Brakes for Building Trailer With 5,200 Pound Axle
    There are a few things going on here that I will attempt to address regarding your axles. The first being that you do not have a brake flange like the # 4-44-1 on these axles. In order to use any type of brakes they will need a brake flange. Based on the condition of the axles I wouldn't recommend welding a brake flange on but if you do you will need to have that done by someone with the right tools and skills to make sure it is correctly aligned. As for the capacity, it does sound right...
    view full answer...
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  • Will Replacement Disc Brake Piston K71-630 for Dexter Axle 8K Caliper Fit 6K Caliper
    I reached out to my contact at Dexter Axle and confirmed that the 1-7/8 inch diameter Replacement Disc Brake Piston # 054-093-00 is in fact used on both the 8,000 lb Dexter calipers # K71-630 as well as the 6,000 lb Dexter calipers # K71-636-00, so this will work well to replace the pistons on your Dexter Disc Brake Kit # K71-647-648 (Nev-R-Lube) or # K71-638-639 (standard). If you also need to replace the piston seals, you can use part # K71-670-00, which also includes the dust boots,...
    view full answer...
  • 6,000 lb Disc Brake Kit with 6 Lug Bolt Pattern for Converting Raptor Toy Hauler to Disc Brakes
    The bearing difference doesn't mean too much since the spindles are the same so regardless of which axle you decide to put the brake kit on you'll need a 6k rated disc brake kit with an 6 lug bolt pattern. So for that we have the Kodiak brake kit part # K2HR526D which is a fit for your spindles. This kit does require the bearings part number # 25580 and # 15123 and seal part # RG06-070 which are sold separately. Or if instead you were wanting a kit that uses an idler hub and a slip-on...
    view full answer...

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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 Brian T
Written by:
Brian T

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