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  1. Trailer Brakes
  2. Hydrastar
  3. Disc Brakes
  4. 7000 lbs Axle
  5. Hub and Rotor
  6. Marine Grade
Hydrastar Disc Brake Kit w/ Actuator for Tandem Axle Trailers - 13" Hub/Rotor - 8 on 6-1/2 - 7K

Hydrastar Disc Brake Kit w/ Actuator for Tandem Axle Trailers - 13" Hub/Rotor - 8 on 6-1/2 - 7K

Item # HSE7K-T1
Our Price: $2,635.99
You Save: $53.54
Trailer Brakes
Shipping Weight: 231 lbs
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Kit includes everything you need to switch your trailer over to disc brakes for improved performance and greater stopping power. Dacromet-coated brakes are corrosion resistant. Perfect for use with boat trailers. Great Prices for the best trailer brakes from Hydrastar. Hydrastar Disc Brake Kit w/ Actuator for Tandem Axle Trailers - 13" Hub/Rotor - 8 on 6-1/2 - 7K part number HSE7K-T1 can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (39)
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Hydrastar Trailer Brakes - HSE7K-T1

  • Disc Brakes
  • 7000 lbs Axle
  • Hub and Rotor
  • Marine Grade
  • 8 on 6-1/2 Inch
  • Hydrastar
  • 1/2 Inch Studs

Kit includes everything you need to switch your trailer over to disc brakes for improved performance and greater stopping power. Dacromet-coated brakes are corrosion resistant. Perfect for use with boat trailers.


  • All-inclusive kit has everything you need to switch your trailer over to disc brakes
    • 4 Disc brake end kits
      • Hub-and-rotor assemblies
      • Grease seals, races and bearings
      • Grease caps (F001526) available separately
      • Calipers with mounting brackets and hardware - attach to 5-bolt brake flanges
    • Hydrastar electric-over-hydraulic brake actuator
      • Hardwires into tow vehicle and signals in-cab brake controller when brakes are applied, triggering pump and motor on actuator
      • Creates smooth, even braking with fast response time
      • Works with most in-cab brake controllers (sold separately)
    • Line kit with brake lines and fittings for tandem-axle trailers
  • Disc brakes deliver better performance
    • Consistent stopping even at highway speeds
    • Shorter stopping distance than most drum brakes
  • Trailer coupler not included


  • Axle capacity: 7,000 lbs
  • Bolt pattern: 8 on 6-1/2"
  • Rotor diameter: 13"
  • Wheel stud diameter: 1/2"

Bearings, Race, and Seal Information:

  • Bearings
    • Inner bearing 25580
    • Outer bearing: 14125A
  • Races
    • Inner race: 25520
    • Outer race: 14276
  • Seal: GS-2250DL
    • Inner diameter: 2.250"
    • Outer diameter: 3.376"

Complete Kit Includes:

  • Hydrastar electric-over-hydraulic trailer brake actuator
  • 7K disc brake kit including hub-and-rotor assemblies with bearings, races, and seals
  • Hydraulic tandem-axle brake line kit
    • (1) 15' Long brake line with 3/8"-24 inverted flare nuts
    • (1) 6' Long brake line with 3/8"-24 inverted flare nuts
    • (2) 4-1/4' Long brake lines with 3/8"-24 inverted flare nuts
    • (4) 18" Male/male rubber flex lines
    • (1) 3/16" Brass T-fitting
    • (2) 3/16" Brass union fittings
    • (1) 3/16" Brass X-fitting
    • 1/2" Nylon hose clamps
    • 3/16" Nylon hose clamps
    • Self-tapping screws

Disc Brakes

More and more people are switching their trailers over to disc brakes, and with good reason. Disc brakes deliver consistent braking - even at highway speeds - unlike drum brakes, which often show a substantial drop in braking torque at higher speeds. In addition, disc brakes offer a substantially shorter stopping distance than drum brakes. Disc brake calipers have only one moving part, rather than the many found in drum brakes. This means that there are fewer parts to maintain, fewer parts to get damaged and fewer parts to have to repair or replace, thus reducing maintenance costs.

Integral Hub-and-Rotor Assemblies

The integral hub-and-rotor is made from cast iron, matching SAE specifications. Cast iron is ideal for high-temperature operations and offers a favorable friction coefficient to ensure adequate stopping power. Furthermore, machined disc brakes minimize the chance of contamination between the hub and rotor, resulting in excellent performance and long life.

E7K-T1 Hydra Star Disc Brake Kit w/ Actuator for Tandem Axle Trailers - 13" Hub/Rotor - 8 on 6-1/2 - 7K

Customer Satisfaction Score:

Customer Reviews

Hydrastar Disc Brake Kit w/ Actuator for Tandem Axle Trailers - 13" Hub/Rotor - 8 on 6-1/2 - 7K - HSE7K-T1

Average Customer Rating:  4.1 out of 5 stars   (39 Customer Reviews)

Kit includes everything you need to switch your trailer over to disc brakes for improved performance and greater stopping power. Dacromet-coated brakes are corrosion resistant. Perfect for use with boat trailers.


I purchased and I installed the Hydrastar Disc Brake Kit HSE7K-T1 along with the Prodigy P3 brake controller on my 42'fifth wheel. As the saying goes "why did I wait so long" , I have been running them for a few months now, I wanted to get some miles and testing on the system before I commented so after several roads trips now about 4000 miles I am very pleased. They have worked flawlessly. I have always been on edge when towing, especially in the mountains with the old electric drum brakes. Now I have so much more confidence in stopping and that lifted so much stress off me. The old electric drum brakes just never felt as if they would stop the trailer especially in an emergency stop, but now if you apply the brakes hard you can feel the trailer stopping the truck. I have never been able to lock up the tires on the camper till now.
If you have a little mechanical knowledge the installation is not difficult as long as you plan things out and be patient.
I did have a few hiccups with shipping and a few parts but thanks to Robert all issues were addressed and corrected ASAP and parts were shipped out to me immediately. A special shout out to Robert which answered so many of my questions and helped me with ordering everything I needed to install my kit. etrailer has always been a pleasure to work with. I will never have an RV without Disc Brakes again. Thanks again to Robert and etrailer.

Woody K.


The Hydrastar disc brake kit that I installed is working great and flawlessly, I would not pull another large rig without disc brakes. I have not had any problems with these products since the installation, no adjustments and no leaks. I just upgraded my suspension to the Road Armor equalizer and wet bolt kit and now have piece of mind with the disc brakes and other suspension upgrades. Very satisfied with all the eTrailer products and their outstanding support team.


This kit was easy to install and our 37’ Montana stops much better than the electric drum brakes they install at the factory! They should put this type on all trailers over 10,000lbs!


I purchased the disc brake system for my 5th wheel to improve the braking. It has proved to be a great unit. We have put over 10K miles on the camper since installing the brakes and I will NEVER have another camper without disc brakes. The system is easy to install. The brake lines took a little planning and I was able to mount the actuator in a convent location and it works great.



Very well


Third trip with trailer all 16 studs on right side sheared off lost both wheels, studs in the hubs are garbage, got no reply from etrailer regarding replacing damaged rotor, Chinese junk

Etrailer Expert

Brooke M.


Thanks for reaching out. I will have our customer service team reach out to you.


Using on 2 out of 3 axles on dump trailer. Two days of use at less then half power setting of brake controller, working great. I added pictures of the install. I do not have pictures of control box mounted. I mounted it inside tool box on trailer.

Dion H.


3 out of 4 calipers working great. One does not release right and eats up the pads fast and right into the rotor.


These brakes work phenomenal. I would never rely on the original electric drum brakes that came on the trailer. It was a diy project and they sent everything I needed to complete the job. When the drum brakes need replacement I would definately go with this set. It stops so much better now and you can see the pads without having to disassemble the entire wheel.


The box’s were in bad shape by the time I picked them up. You did a good job taping them up otherwise most of the small parts would have not been there. One of the brake lines was crushed. I will have to replace it


Best system I've ever had on a trailer..


I have no issues with the Hydra Star. The system works flawlessly, but the reservoir could use a sight gage.
The only issue was the packaging/shipping. I initially received shortages after two shipments, and then duplicate parts upon receiving the aforementioned parts shortage. Also, the initial shipment included calipers with two different styles of pads.


I don't like the fact that you should not keep the brakes on while at stop light.

Also, having trouble with on board brake controller running it. 2020 GMC 2500HD will activate brakes once but if you let up a bit then step down, I have no trailer braking. Very dis-concerting.

Etrailer Expert

Jenny N.


You mentioned that you were not happy with the braking experience of the GMC with the actuator. The actuator of the HydraStar Disc Brake Kit w Actuator for Tandem Axle Trailers # HSE7K-T1 will maintain brake pressure as long as the brake controller is telling the actuator to maintain it, but what most brake controllers have is a function that after a certain amount of time with the brakes applied the controller stops sending voltage as it assumes you are at a stoplight. I am not sure if your OEM controller stops sending voltage if you let up a little and then reapply the brakes. As far as I know there is not a ready-made solution to change it.


Great powerful brake! With putting these on my 14k toyhauler i will never go back to the old 40 era drum brakes!!!


Great product.


Very help and quick delivery


Best improvement I've ever made on my 5th wheel... kit had everything to do the job


Prompt delivery time but poor packaging-the items looked like used parts.several items were missing or damaged. etrailer promised to replace entire order.


Samuel was terrific helping me determine the best fit for my RV. Can't wait to have them installed. eTrailer is very responsive and knowledgeable. I recommend them to all RV owners!
Thanks to Samuel C!



Great brake system


Amazing difference in braking power! Rv drum brakes are junk by comparison!


received the kit. NO actuator, had to return what parts I had back.


Replaced the drum brakes on my Heartland RV with HydrasStar disc brakes went on vacation out West for 4 weeks as we were coming off Teton Pass Informed Wife Best investment I have made on our rv.


Got my order today, no actuator that was to be in the kit HSE 7K-T1. Again I’m in a holding pattern.

Etrailer Expert

Jenny N.


I will have our Customer Service team reach out to you.


After pne year and approximately 6,000 miles I'm very pleased with the brakes' performance. My tow vehicle and trailer feel as one umit when braking. The stopping distance considerably less. I haven't once had to say to myself "please stop" in a hard braking situation.


One of the best upgrades we made to our 5th wheel camper.



Great service great shipping but ordered rubber brake lines and they sent me steel lines


Great product!

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Info for this part was:

Employee Mike L
Expert Research:
Mike L
Employee Jameson C
Expert Research:
Jameson C
Employee Lindsey S
Edited by:
Lindsey S
Employee Kathleen M
Installed by:
Kathleen M
Employee Dustin K
Video by:
Dustin K
Employee Chris R
Video Edited:
Chris R
Employee Wilson B
Updated by:
Wilson B
Employee Michael B
Updated by:
Michael B
Employee Noah M
Updated by:
Noah M
Employee Manda E
Updated by:
Manda E
Employee David F
Test Fit:
David F
Employee Kristina F
Written by:
Kristina F

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