bing tracking image
  1. Trailer Brakes
  2. Hydrastar
  3. Disc Brakes
  4. 7000 lbs Axle
  5. Rotor
  6. Boat Trailer
  7. Snow Trailer
Hydrastar Disc Brake Kit w/ Actuator for Single Axle Trailers - 13" Rotor - 8 on 6-1/2 - 7K

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

Item # HSE7K-S1SO
Our Price: $1,498.78
Trailer Brakes
This item qualifies for Free Shipping
Shipping Weight: 125 lbs
In Stock
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


Need help with installation?
Locate installers near me
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 Single Axle Trailers - 13" Rotor - 8 on 6-1/2 - 7K part number HSE7K-S1SO can be ordered online at or call 1-636-306-4830 for expert service.
  • All Info
  • Q & A (0)
  • Videos (1)
  • Photos
  • Why etrailer?

Hydrastar Trailer Brakes - HSE7K-S1SO

  • Disc Brakes
  • 7000 lbs Axle
  • Rotor
  • Boat Trailer
  • Snow Trailer
  • 8 on 6-1/2
  • 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
    • 2 Disc brake end kits
      • Slip-on, cast iron, over-the-hub rotors
      • 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 single-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"

Complete Kit Includes:

  • Hydrastar electric-over-hydraulic trailer brake actuator
  • 7K disc brake kit over-the-hub rotors
  • Hydraulic single-axle brake line kit
    • (1) 30' Long brake line with 1/16"-24 inverted flare nuts
    • (1) 6' Long brake line with 3/8"-24 inverted flare nuts
    • (2) 18" Male/male rubber flex lines with 3/8"-24 inverted flare nuts
    • (1) 3/16" Brass T-fitting
    • (1) 3/16" Brass union fitting
    • (1) 3/16" to 1/4" Brake line adapter
    • (1) 1/4" to 3/16" Step-down adapter
    • 1/2" Nylon hose clamps
    • 3/16" Nylon hose clamps
    • 1/4" 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.

Over-the-Hub Rotors for Easy Replacement

Slip-on, cast iron rotor makes it easy to convert an idler axle to a disc brake axle. Simply place the rotor over your hub. It is most often wheel bolt piloted for a loose fit and then held in place by the wheel itself. With a separate rotor and hub, you can easily repair or replace one element of your brake system without having to junk the whole thing.

The 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. Rotors are vented to effectively dissipate heat, dramatically reducing the incidence of heat-related damage.

E7K-S1SO Hydra Star Disc Brake Kit w/ Actuator for Single Axle Trailers - 13" Rotor - 8 on 6-1/2 - 7K

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

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

Video Transcript for Review of Hydrastar Trailer Brakes - Disc Brake Kit - HSE7K-S1SO

Today we're going to take a look at the hydra star disc brake kit with the brake actuator, for 7,000 pound single axle trailers with the eight on six and a half inch bolt pattern. Now this is a complete kit, will include everything I have laid out here on the table. We'll start with the hydra star 1600 PSI electric over hydraulic trailer brake actuator. You also get the 7,000 pound disc brake kit that uses the over the hub rotors, and that kit will include two of these 13 inch diameter Dacromet rotors, two of the Dacromet calipers with brake pads, and in two of the Dacromet caliper mounting brackets. It comes with all the hardware. Now the Dacromet coating on these parts are corrosion resistance, so they are perfect for use with boat trailers.

You also get this hydraulic single axle brake line kit right here in the middle and that kit will include this 30 foot long steel brake line, six foot long steel brake line, two 18 inch long rubber flex lines, and then all your fittings, clamps and screws need to install the brake line kit.This is an all inclusive kit, has everything you need to switch your trailer over to disc brakes. The two disc brake end kits, they have this slip on cast down over the hub rotors. Now to install this on your trailer, it does require that your axle should have the eight lug idler hub assemblies with the half inch studs, and just to show you what that looks like, I pulled one of those. This is one of the hub assemblies that would, these would fit over. In other words, this would need to be on your axle and then what you'll do is take this slip on rotor, slide it right over there onto the studs and then tighten it down using the wheel lug nuts.Now the calipers with these mounting brackets and the hardware, they will attach to five bolt brake flange also, so you do need to have the five bolt brake flange on your axle, the hydro star electric over hydraulic actuator right here.

This will hard-wire into your, into your tow vehicle and signals that are in-cab brake controller when your brakes are applied triggering the pump and motor on this actuator. This will help create a nice smooth even braking with fast response time and it is designed to work with most of the in-cab brake controllers and we do sell those separately also and the brake line kit with the brake lines and fittings are for single axle trailers.Now disc brakes will deliver better performance than drum brakes because they'll give you much better, more consistent stopping even at highway speeds and also shorter stopping distances than the drum brakes.Now a trailer couplers not included. A few specs on this again, the axle capacity they sit on are 7,000 pound axles. Bolt pattern we mentioned is eight on six and a half and the rotor diameter is 13 inches. The wheel studs, these we're fit on is a half inch diameter.

Now this kit is for a single axle trailer. We do also offer on our website the kits for a tandem axle trailer, which is part number HSE7K-T1SO that's sold separately. And also we have a kit for a triple axle trailer, part number HSE7K-TR1SO. And again, that's sold separately also, but that should do it for the review on this hydro star, disk brake kit with the brake actuator for 7,000 pounds, single axle trailers.


See what our Experts say about this Hydrastar Trailer Brakes

  • Dexter or Hydrastar Actuator Kit for Trailer with 7k Axles
    The Hydrastar actuators like what comes with the Hydrastar Disc Brake Kit part # HSE7K-S1SO are widely considered to be the most reliable and fastest reacting so this would be what I recommend. This specific kit is for a single brake axle so if you plan to have brakes on both of your axles you'd instead want the part # HSE7K-T1SO which includes the second axle as well. Then for a brake line kit the part # T4830000 would be what you'd want as well.
    view full answer...

  • Why

    At we guarantee:
  • 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 trailer brake 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:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jeff D
Installed by:
Jeff D
Employee Jameson C
Expert Research:
Jameson C
Employee Wilson B
Updated by:
Wilson B
Employee Manda E
Updated by:
Manda E
Employee Kristina F
Written by:
Kristina F

At 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. Let us know if anything is missing or if you have any questions.

Product Experts Available Now!
Call 1-636-306-4830