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

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

Item # HSE7K-T1SO
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Our Price: $1,918.97
Trailer Brakes
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Shipping Weight: 225 lbs
Hydrastar 7000 lbs Axle Trailer Brakes - HSE7K-T1SO
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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. Lowest Prices for the best trailer brakes from Hydrastar. HydraStar Disc Brake Kit w/ Actuator for Tandem Axle Trailers - 13" Rotor - 8 on 6-1/2 - 7K part number HSE7K-T1SO can be ordered online at etrailer.com or call 800-298-1624 for expert service.
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  • Q & A (3)
  • Videos (1)
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Hydrastar Trailer Brakes - HSE7K-T1SO

  • Disc Brakes
  • 7000 lbs Axle
  • Rotor
  • 8 on 6-1/2
  • Brake Kit with Actuator
  • 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
      • 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 including over-the-hub rotors
  • Hydraulic tandem-axle brake line kit
    • (1) 30' 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.

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-T1SO Hydra Star Disc Brake Kit w/ Actuator for Tandem Axle Trailers - 13" Rotor - 8 on 6-1/2 - 7K

Video of HydraStar Disc Brake Kit w/ Actuator for Tandem 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 - Tandem Axle Disc Brake Kit - HSE7K-T1SO

Today we're going to take a look at the Hydrastar disc brake kit with the brake actuator for the tandem 7,000 pound axle trailers, and with the eight on 6-1/2 inch bolt pattern. Now this is a complete kit. It includes the Hydrastar 1600 PSI electric over hydraulic trailer brake actuator. It includes 7,000 pound axle disc brake kits with these over the hub rotors. Includes four of the 13 inch diameter dacromet rotors, four of the dacromet calipers with brake pads, and then four of the dacromet caliper mounting brackets.Now the dacromet coating on these parts are corrosion resistant, so they're perfect for use with boat trailers. The brake line kit, which is in the front row there, this hydraulic tandem axle brake line kit will include a 30 foot long steel brake line, six foot long steel brake line, two of the 4-1/4 foot long steel brake lines, four of the 18 inch long rubber flex hoses, and then all your T fittings, X fittings, union fittings, hose clamps and screws to install our brake line kit.This is an all inclusive kit.

Has everything you need to switch your tandem axle trailer over to disc brakes. We had mentioned has the four disc brake end kits, these slip on cast on over the hub rotors. Now to install these, it will require that your axles have the eight lug idler hub assemblies with half inch studs, and just so you know what we're talking about, I happen to pull one of those idler hub assemblies. And this is what the idler hub assembly would look like.It's just your hub with the studs on it, the half inch studs. Basically with this on your trailer, all you have to do is slide these rotors right over those studs, and then they'll be held in place by the wheel lug nuts.

Now the calipers with the mounting brackets and all the hardware, they are designed to attach to the five bolt brake flanges on your axle. And then we mentioned this hydraulic brake actuator right here. This is an electric over hydraulic brake actuator.It will basically hard wire into your tow vehicle and it'll signal the in-cab brake controller when the brakes are applied, triggering you to pump in the motor on the actuator, and that'll create a nice smooth even braking with the fast response time. And it is designed to work with most in-cab brake controllers. We do sell those separately on our website.

And the brake line kit we have mentioned comes with all the brake lines and fittings for a tandem axle trailer.Now disc brakes are much better performance than drum brakes. They'll give you more consistent stopping even at highway speeds. And at highway speeds, the drum brakes seem to drop in torque so the disc brakes will do better there. And they also give you the disc brakes will give you shorter stopping distances than most drum brakes. Now the trailer coupler is not included.A few specs on this again, the axle capacity, it's designed for 7,000 pound axles.

The bolt pattern, again we mentioned is eight on 6-1/2 inches. The wheel stud diameter is a half an inch and the diameter on the rotor is 13 inches. Now just to mention, this is for a tandem axle trailer. If you do happen to want to do this to a single axle, or a triple axle trailer, we do sell those kits also. They're sold separately on our website. The part number on the single axle trailer kit is HSE7K-S1SO, and if you're doing good on a triple axle trailer, part number is HSE7K-TR1SO. But that should do it for the review on the Hydrastar disc brake kit with the brake actuator for tandem 7,000 pound axle trailers.


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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 Jeff D
Installed by:
Jeff D
Employee Kristina F
Written by:
Kristina F
Employee Noah M
Updated by:
Noah M

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