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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 Single Axle Trailers - 13" Hub/Rotor - 8 on 6-1/2 - 7K

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

Item # HSE7K-S1
Our Price: $1,666.17
Trailer Brakes
Shipping Weight: 125 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 Single Axle Trailers - 13" Hub/Rotor - 8 on 6-1/2 - 7K part number HSE7K-S1 can be ordered online at or call 1-800-940-8924 for expert service.
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Hydrastar Trailer Brakes - HSE7K-S1

  • 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
    • 2 Disc brake end kits
      • Hub-and-rotor assemblies
      • Grease seals, caps, races and bearings
      • 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"

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 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.

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-S1 Hydra Star Disc Brake Kit w/ Actuator for Single Axle Trailers - 13" Hub/Rotor - 8 on 6-1/2 - 7K

Video of Hydrastar Disc Brake Kit w/ Actuator for Single Axle Trailers - 13" Hub/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 Brakes - HSE7K-S1

Ellen: Hey everyone, I'm Ellen here at, and today we're going to be taking a look at the HydraStar disc brake kit. This is going to come in a couple of different configurations, and I'll go over more specifically what comes in each kit later on in the video. But this'll be available for your single, your tandem, and your triple-axle trailers.Basically the reason why you'd want to get this kit is because it's going to give you the hub and rotor assemblies to replace the old brakes on your trailer, and give you a new disc brake and caliper system. The advantage with that is that we're going to have a lot more stopping power for our trailer. If you've ever hauled one down the road, you can know that those hub and drum assemblies, that older style, typically you're going to have a longer distance to travel to get that trailer to stop fully, and it's just not as safe. A lot of times it can cause us to feel like we really have to give ourselves a lot of room to be able to stop that whole rig successfully.In addition to that, those hub and drum brakes, they just don't have as much breaking torque whenever we're at highway speeds, so this is going to be a great improvement over that.

You're going to be just thrilled with how much you can stop your trailer really easily. You can really stop it on a dime with these. If you kind of look at them with that disc and caliper system, this is much more similar to what you'd see in an automotive setup as something in your vehicle. This is going to be the newer technology, that old hub and drum assembly that's going to be kind of like your grandmother's assembly. It's an older technology, it's effective, but it's just outdated at this point.

This is going to be a much more efficient system to get your trailer stops to make it more safe to be out on the road and to have that better control while you're towing that fifth wheel trailer or your larger trailer down the road.You can see that I have kind of a lot of stuff laid out here, so we'll go over what comes in the kit. These are going to be our hub and rotor assemblies. They are going to be made out of a cast iron material, so they're going to be very durable, long lasting. They do have fins or segmentation on the back here. You can kind of see it a little bit better on this one.

That's to help dissipate the heat out so that they don't get too hot, helps you keep everything cool as you're going down the road. Our calipers, the assemblies to actually mount our calipers on the axle. Our hard lines for that brake line going back. The actuator, our bearings, seals, the flexible hoses. That's going to actually connect to those calipers and that helps to give your axle some room to travel.

It gives that suspension a little bit of room to move, so that's why we have the flexible lines going to each of our calipers there. And then we'll have all the hardware including the tees and unions, and also the clamps to hold up all our lines, some hardware as well. That way we can run everything nice and neat, and keep everything tidied up underneath our trailer.The other nice thing about having this all-in-one kit is that you don't have to piecemeal everything together yourself. It's all going to be there for. You don't have to really pick up anything else. The only thing that isn't included with this is your coupler or your brake controller. Those are things that are going to be separate, but as far as the brake goes, you're going to have all the stuff you need. Kind of what I have here, this is more or less going to be what's in the single-axle configuration. Once we get into the tandem, that's when you have this extra pair of the rotors, calipers, hoses, bearings, brackets. And then the triple from there would be pretty much this table again over to the left, so that's basically what comes in your kit, but it's going to be everything you need.The other thing that I really like about that is that we're going to have all of this new at the same time. It's all going to wear at the same time. We don't have to worry about having to replace one thing here or there, or kind of not really knowing when we put everything on, it's going to be a lot easier to maintain and not have to worry about those components. With the disc assemblies, again, compared to that old hub and drum assembly, there's just a lot less moving parts to actually stop your trailer. So we have those brake pads inside here. Those bolts just fell out. It's no big deal, but you see those brake pads, that's similar, like I said, to that automotive style. This is actually all it's going to be moving. It's just this pad going in and out to put that pressure on that rotor and bring you to a safe stop. Over time, that brake pad of course is going to wear down, but it's going to be a lot simpler to replace that rather than the whole brake assembly from your older style system.Again, the big advantage, be able to stop quicker, have more responsive braking as well, and give you that more consistent stopping force even when you're at highway speed. As far as the capacities with the specs for it, it's going to have an axle capacity of 7,000 pounds. Our bolt pattern for these hubs is going to be eight, two, three, four, five, six, seven, eight on six and a half. So if we go from the center of one stud to the center of the other, that's eight and a half inches apart. The rotor diameters, the outer diameter here is 13 inches. Our wheel studs are going to be a half inch in diameter. That's pretty much going to do it for our look at the HydraStar disc brake kit. I hope this video has been helpful in deciding if this is going to be the right kit for you, but I think this is going to be a great addition for your trailer, gets you back out on the road with a lot safer brakes for your adventure. Thanks for watching.


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...
  • Converting Hydraulic Drum Brakes to Disc Brakes.
    We definitely have options to convert hydraulic drum brakes to hydraulic disc brakes. The Kodiak Disc Brake Kit # K2HR712D is designed to work with a 7,000 pound axle that has wheels that use an 8 on 6 1/2 bolt pattern and the inner bearing # 25580 and outer bearing # 14125A. You would want to match these to your existing bearing to verify the fit. I have an article included that helps with converting hydraulic drum brakes over to disc brakes that should make this easier. You can also...
    view full answer...
  • Will EOH Disc Brakes Work Better for 3,500 lb Axle than Drum Brakes
    Disc brake setups are all around better than drum brakes so if you were looking for a setup that's going to last longer and also work a lot better investing in an electric over hydraulic disc setup for your trailer would be a great option. To do that you would want the part # HBA16-252-82 for all of the hydraulic and electric components and then for the brake kit for your axle you would want the part # K2HR35D which fits a 3,500 lb axle and you'd be set.
    view full answer...
  • Recommended Disc Brake Conversion Parts for a 5th Wheel Trailer w/ 8,000 lbs Axles
    I would be happy to. Since your 2019 Heartland RV Landmark has 8,000 lbs axles you will need the Kodiak Disc Brake Kit item # K2HR89DD. These will replace the hubs and drums you have with rotors and hubs. The mounting brackets will attach to the flanges you already have. These are dacromet-plated rotors that have a 8 on 6-1/2 bolt pattern. You will need one set per axle. For an actuator, brake lines, and a breakaway kit you will want the Hydrastar Electric Over Hydraulic Actuator Kit...
    view full answer...

Do you have a question about this Trailer Brake?

Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Kathleen M
Installed by:
Kathleen M
Employee Wilson B
Updated by:
Wilson B
Employee Noah M
Updated by:
Noah M
Employee Manda E
Updated by:
Manda E
Employee Kristina F
Written by:
Kristina F

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