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HydraStar Marine Electric Over Hydraulic Actuator w/ Breakaway and 7-Way RV Harness - 1,600 psi

HydraStar Marine Electric Over Hydraulic Actuator w/ Breakaway and 7-Way RV Harness - 1,600 psi

Item # HS381-9067
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HS381-9067 - Disc Brakes Hydrastar Brake Actuator
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Vented, marine-grade aluminum electric-hydraulic actuator lets you use your brake controller (sold separately) to activate your trailer's hydraulic disc brakes. Includes wiring, 7-way harness, and breakaway. Brake lines sold separately. Call 800-298-8924 to order Hydrastar brake actuator part number HS381-9067 or order online at etrailer.com. Free expert support on all Hydrastar products. Guaranteed Lowest Price and Fastest Shipping for HydraStar Marine Electric Over Hydraulic Actuator w/ Breakaway and 7-Way RV Harness - 1,600 psi. Brake Actuator reviews from real customers.
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Hydrastar Brake Actuator - HS381-9067

  • Electric-Hydraulic Brake Actuator
  • Disc Brakes
  • Hydrastar
  • 1600 psi

Vented, marine-grade aluminum electric-hydraulic actuator lets you use your brake controller (sold separately) to activate your trailer's hydraulic disc brakes. Includes wiring, 7-way harness, and breakaway. Brake lines sold separately.


  • Electric-over-hydraulic brake actuator activates your trailer's hydraulic brakes when you apply the brakes in your tow vehicle
    • Brake controller (sold separately) is required to send signal from tow vehicle to actuator when brakes are applied
    • Included 7-way trailer connector transmits signal from brake controller
  • Improved functionality when compared with surge brake couplers
    • Faster response time - trailer brakes are triggered when you apply brakes in tow vehicle, as opposed to when trailer pushes against hitch ball
    • No need to manually lock out brakes when you back up
    • Trailer brakes can be intentionally activated when you reverse
    • Manual override on brake controller can be activated so you can engage the trailer brakes without having to apply your vehicle brakes
  • Electronic, proportional pressure valve ensures that braking is smooth and effective
  • Vented end plate releases pressure, moisture, and heat in order to protect the internal components
    • Allows actuator to be mounted in places where most actuators would overheat
  • Built-in bleeder screw on actuator lets you easily flush air out of your brake lines
  • Durable extruded aluminum construction provides superior corrosion resistance
    • Marine-grade gasket and stainless steel hardware make actuator ideal for marine use
  • Breakaway system activates your trailer's brakes if the trailer disconnects from the tow vehicle
    • Battery charger ensures the system's battery is always charged
    • Weather-resistant polymer case is top loading for easy access from above
    • Built-in mounting bracket offers simple installation
  • Insulated 7-way, RV-style trailer connector is molded to protect wires and terminals
  • Weatherproof, corrosion-resistant 7-pole junction box protects wires, eases installation, and makes diagnostics simple
    • Ring terminals and butt connectors included for connecting wiring
  • Wire loom protects wiring from the elements and allows wires in and out along any point of the loom for easy installation
  • Mounting pads have adhesive backing for securing cable ties
  • Kit includes:
    • HydraStar marine electric-over-hydraulic actuator (Model MHBA-16)
    • Breakaway system
    • 7-Way trailer connector
    • 7-Pole junction box
    • 6' Split wire loom
    • 4 Mounting pads
    • Mounting and wiring hardware
  • DOT compliant
  • Made in the USA


  • Application: single-, tandem-, or triple-axle trailers with disc brakes
  • Maximum output pressure: 1,600 psi
  • Power: 12V DC
  • Hydraulic port size: 3/16"
  • Actuator dimensions: 11-3/4" long x 3" wide x 7-3/8" tall
  • Actuator wire configuration:
    • Black: 12-volt power
    • Blue: brake controller
    • Yellow: breakaway
    • White: ground
  • Battery capacity: 5 amp-hours
  • Breakaway battery case dimensions: 5-7/16" long x 4-1/4" wide x 4-1/4" tall
  • Battery dimensions: 3-7/8" long x 3-1/2" wide x 2-11/16" tall
  • Breakaway switch lead wire length: 7-1/2"
  • Trailer connector length: 6'
  • Trailer connector wire gauges:
    • Black/white: 10 gauge
    • Blue: 12 gauge
    • Brown/red/green/yellow: 14 gauge
  • Junction box dimensions: 6-3/4" long x 3-1/2" wide x 2-1/4" tall
  • Split wire loom length: 6'
  • 2-Year limited warranty

Note: Do not power wash the HydraStar actuator or take it through a commercial car wash. High-pressure water may damage the seals on the actuator.

The HydraStar electric-over-hydraulic trailer brake actuator applies pressure to your trailer's hydraulic brake system in response to the electrical signals sent from your in-cab brake controller. As a result, your trailer's hydraulic brakes will be activated every time you apply the brakes in your vehicle or press the manual override on your controller.

Pair the HydraStar electric-over-hydraulic actuator with your trailer's disc brakes to get the best possible braking setup. With disc brakes, you already have more consistent braking at higher speeds and a shorter stopping distance than you'd get with drum brakes. In addition to more reliable braking, you also have less cost to maintain the brakes as there are fewer moving parts. Combine these benefits with an electric brake controller and you'll get greater control over your already superior brakes, providing you with the best braking performance.

HydraStar Electric-Over-Hydraulic Actuator vs. Standard Surge Brake Actuators

With the HydraStar electric-over-hydraulic actuator, you can get all the benefits of towing with an electric brake controller while using hydraulic brakes. Because this actuator will activate according to the settings you have chosen for your brake controller (sold separately), you will have more control over when and how your trailer brakes engage. Depending on the features of your brake controller, you may be able to control both the rate and intensity with which your trailer's brakes activate. You can also use the manual override on your brake controller, which allows you to engage the trailer brakes without having to apply the brakes in your vehicle. And perhaps most impressive, if you have a proportional brake controller, your brakes will be activated with an intensity that matches the braking speed and power of your rig.

This pump-and-motor-based system increases response time compared with traditional actuators because the trailer brakes are triggered when you apply the brakes in the tow vehicle, as opposed to when the trailer pushes against the hitch ball. This not only gives you faster, more efficient braking, but it also eliminates the pushing sensation that occurs in setups that use standard surge brake actuators.

HydraStar actuators are also beneficial because, unlike standard surge couplers, they allow you to activate your brakes when reversing down an incline, such as a boat ramp. Having the ability to brake in reverse gives you more control and prevents wear on your tow vehicle.

HydraStar Installation

Hydrastar Installation Diagram

This HydraStar electric-over-hydraulic brake actuator will give you years of trailer-stopping performance. The actuator mounts on your trailer's frame with the included stainless steel hardware. The included 7-pole junction box with color-coded studs makes it simple to splice into your trailer's wiring and to connect the provided 7-way trailer connector. Once the actuator is correctly wired, you can connect your trailer's hydraulic brake lines to the 3/16" female port. Lines and fittings are sold separately.

Durable, Marine-Grade Construction

The HydraStar Marine actuator is ideal for use on boat trailers. Just like other HydraStar electric-over-hydraulic actuator models, this system is built of extruded anodized aluminum for superior corrosion resistance. The weathertight seals protect internal components from the elements. The HydraStar Marine actuator also features marine-grade gaskets and stainless steel hardware that won't rust. These extra features make it perfect for marine applications.

This actuator also has a vented end plate that releases pressure, moisture, and heat to help prevent any internal damage. Unlike models that are unable to release heat and pressure, this vented actuator can be safely mounted inside of a compartment on your trailer. As a result, this actuator is great for gooseneck and fifth-wheel trailers where finding space on the tongue can be nearly impossible.

Breakaway Kit

Required by law in most states, a breakaway system will activate your trailer's brakes in the unlikely event that your trailer disconnects from your tow vehicle. This kit wires to the included battery and to the HydraStar actuator. If your trailer separates from your tow vehicle, the breakaway kit signals the actuator to apply the brakes.

Brake Controller Compatibility

Not all electric trailer brake controllers will work with this electric-over-hydraulic brake actuator. See the following table to determine compatibility with common models of brake controllers. For best performance, it is recommended that you use an aftermarket electric brake controller rather than an OEM factory-installed controller.

ManufacturerVehicle Years/Controller ModelsCompatibleCompatible if Used with HBA-CAM
Brake ControllersDraw-TiteActivator (5100)Yes
Activator II (5500 or 5510)Yes
Activator III (5520)Yes
Activator IV (5504)Yes
HayesEnergize III (81741B)Yes
Energize III+ (HA81742B)Yes
Energize XPC (HA81745)Yes
Engage (HA81760)Yes
G2 Brake Boss (81792BB)Yes
Syncronizer (HA81725)Yes
Endeavor (81770)Yes
Genesis (HA81790)Yes
Blackbird (HA81726)Yes
HopkinsImpulse Digital (47325)Yes
Insight (HM47297)Yes
Brake Force (47225)No
Reliance (47284)No
Agility (47294 or 47295)No
MaxbrakeBrake ControllerYes
RedlineRedline TA900Yes
TekonshaProdigy (90185)Yes
Prodigy P2 (90885)Yes
Prodigy P3 (90195)Yes
Primus IQ (TK90160)No
PowerTrac (39523)Yes
Voyager (39510 or 9030)Yes
ValleyVA32812 BlackbirdYes
VA32811 PhantomYes

381-9067 Cargo Towing Solutions (formerly Carlisle) Hydra Star Marine Surge Brake Conversion Kit - 1600 psi - Model MHBA-16-CON

Video of HydraStar Marine Electric Over Hydraulic Actuator w/ Breakaway and 7-Way RV Harness - 1,600 psi

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

Video Transcript for HydraStar Marine Electric Over Hydraulic Actuator Installation

Speaker 1: Today we're gonna be having a look at and showing you how to install the HydraStar Marine Electric Over Hydraulic Actuator with Breakaway and Seven Way RV Harness, rated at 1,600 PSI, this is part number HS381-9067. Now the reason you're gonna want an electric over hydraulic actuator to control your trailer brakes such as this one is because it's far superior than your typical surge coupler style brakes that your boat trailer's normally have. With your surge breaks you have no control over it whatsoever, with this you can dial up or down the intensity of the brakes being applied with the brake controller inside your truck.Also when you go to back up your trailer with surge brakes as soon as you start to back up the brakes are being applied, the more force they're using to back up the harder the brakes are gonna be applied unless you have a manual lock out which you have to get out of your truck, engage the lock out so you can back up without the brakes being applied. With this where you have your brake controller set up at when you're backing up that's how much the brakes are gonna be applied so it makes it easier to back your boat into the water down the ramp but yet you still have some brake assistance there so you don't have all the weight of the boat or the trailer dragging you into the water.Also with the surge coupler the way the brakes are applied is the weight of the boat and the trailer start to push the coupler against your truck and as the coupler collapses it applies pressure to the fluid and engages the brakes so there is a delay of the brakes being applied. With the actuator here being electric over hydraulic it's immediate, there is no delay so as soon as we start to activate our brakes in our vehicle the brakes are being applied in our trailer. Now this is a marine rated actuator, by being marine rated we have an aluminum construction here which is corrosion resistant and it is also vented to help relived pressure and let moisture escape.

This will ensure that our brakes will operate appropriately and we don't get any moisture inside our unit causing corrosion and damage. Our gaskets inside are also marine rated so you don't have to worry about salt water corroding them.Now what's great about this kit compared to other option out there is that this comes with everything you need in order to convert your existing boat trailer or other trailer that has hydraulic surge brakes over to one that has electric over hydraulic set up. We have our actuator and new junction box to hold all of our wiring and a seven way plug so we can utilize the brake controller inside of our vehicle which is great since most boat trailers only come with a five pole flat to get the reverse signal out to your lockout for your actuator. We also have this breakaway kit with this nice battery box here which is self charging so you don't have to worry about taking the battery out to charge it, it has a built in charger, and we can check the condition of the battery by pushing this button on the top. We also have the breakaway switch which will apply our trailer brakes in the unlikely event that our trailer came disconnected from our truck.

With the pin pulled you can hear the brakes being applied.This kit is rated up to 1,600 PSI so it'll be perfect for our disc brake applications on our trailers. It is rated to support trailers up to three axles, anywhere from one to three. The one thing that I really like about this kit and with electric over hydraulic brakes in general when comparing them to surge couplers by having so much more control over them we can activate our brakes manually from inside our vehicle by using the manual brake override on our brake controller so if our trailer starts to sway side to side on us and we need to bring it back and align our vehicle we can use the manual override by sliding the adjuster over just to slow our trailer down and bring it back in line. With the surge coupler you can't do that, many of our customers feel that this is a much safer way of towing their trailer behind their vehicle.Now when comparing this actuator to other electric over hydraulic actuators out there such as the Dexter DX series this is a much slimmer design actuator so we're much more versatile in our mounting solutions, it'll work great on top of narrow channel frame trailers such as this one. Now for a few measurements to better assist you in choosing mounting locations for your components our actuator measures 11 and three quarters inches long, it is three inches wide at its widest point, and it is seven and three eighths of an inch tall from the bottom to the top of the cab.

Our junction box at its longest points measures six and three quarters of an inch long, at its widest point it is three and a half inches wide, and it is two and a quarter inch tall. Now the battery box for our breakaway system is five and 7-16ths of an inch long, it is four and a quarter inch wide, it is also four and a quarter inch tall. Our seven way cable measures six feet long from the very end to where it goes into our junction box.Now that we've gone over some features we'll show you how to get it installed. To begin our install we need to find a place to mount our actuator, in our particular case since we are working on a boat trailer which already had hydraulic surge brakes on it we're gonna mount ours on the center channel of our trailer here because this will protect it the most from side to side, we also want to make sure that our hydraulic fitting is facing where the brake line comes out of our current cylinder. We'll take a drill now and go through each one of the holes in the four corners to make a pilot hole.

With our pilot holes now driller we'll now secure it in place with our provided self tapping screws.Now we need to find a spot to mount our junction box for all the wiring. We're just gonna put ours right behind our HydraStar unit, this way our wires can easily go inside the unit. We'll mark out our holes by making a pilot hole with our drill, now in our junction box here I like to point out there's two holes on one side and one hole on the other side. We want to have the side of our two holes facing towards the front of our trailer that way we'll have our seven way come out of one hole and then the wires that go in from our HydraStar unit will go in the other hole. Now we'll secure this in place with our self tappers.Now we need to find a position to mount our breakaway switch. We're gonna mount ours on the outside of our passengers side of our trailer right here as far front as we possibly can. We don't want to attach to our coupler area here because this coupler will be replaced at some point with one that is not a hydraulic surge coupler. We'll mark where we want it and drill a pilot hole. Now we'll mount our breakaway switch, ensuring that our pin faces the front of the trailer, line up the hole, ensure that it's as level as possible, and we'll secure it in place with the self tapping screw.Now we need to find a location to mount our breakaway battery box. We're gonna mount ours on the inside of our passengers side frame about right next to where we mounted our junction box. Now depending on your application this may be a little bit more difficult for you to do because of clearance so we're using a right angle drill to make this easier for us. We're gonna mark out our top holes first. Okay we have our upper holes marked out now so now we're going to drill those holes out completely. Okay now we'll secure it in place with our self tapping screws. We went ahead and repeated the same process for our bottom screws, this way our breakaway battery box is securely mounted.Now we can start working on our wiring, we'll lift off our cover for our junction box, inside we'll find several color coded terminals. We'll take the end of our seven way now and one of our plugs here, you'll notice how the plug is sealed where there's a small pin hole in it, we'll just poke our wires through that pin hole. Okay with the wires poked through we'll just push this down until it's covering our sleeve here on the wiring, we'll have the flat part facing up and we'll slide this opening here through the slot in our box. Now we'll take our wire clamp here, sit it over our seven way wires, and we'll clamp the wires in place with our provided screws.Our junction box is color coded to the exact same colors of the wires from our seven way connector so we'll strip back insulation from each wire, crimp on a connector, and match it up to the corresponding color. Now some of these wires are thicker than other ones, for the thicker wires we'll use the yellow connectors, for the thinner wires we'll use the blue connectors. The yellows are meant for 10 to 12 gauge wiring and the blues are meant for 14 to 16 gauge. Now as we work our way closer to where our connector enters the box we can actually cut off excess wiring so we don't have to have too much slack inside here and it gives us a cleaner install.Now the ring terminals that we crimped on are heat shrink ring terminals so we'll use a heat gun to shrink down the ring terminals to make sure we have a nice weather tight seal. You'll want to use a heat gun over a lighter because a heat gun does provide a source of indirect heat versus an open flame, the indirect heat won't damage the connector like a direct flame will from a lighter, we have these heat guns available on our website. Here's what it looks like with our heat shrink ring terminals shrunk down, you can see it goes around our wire and seals nicely so we don't have to worry about any moisture getting inside.Now we'll take the wires that come from our HydraStar unit itself, we'll separate the yellow one so we'll just have the black, the blue, and the white, we'll take another one of these grommets here and we'll push those three wires through it. Now we'll take the three wires from our breakaway battery, we'll separate the blue taking the black and the white, and we'll push those through that grommet as well. Now we'll take the wiring that went to our existing trailer plug, we already went ahead and cut that off, and we're just left with the wiring that runs our lights for our taillights, our marker lights, and turn signals and brake lights. We'll shove that through the grommet as well.Now we'll take the short segment of white wire that comes with the kit and this will be our ground wire for our trailer and we'll shove this through the grommet. With all of the wires that we now need through our grommet we can place the grommet inside the junction box. Now we'll take our clamp, go over our wires, and we'll secure them in place so they don't get pulled out.Now we'll take the blue wire from our HydraStar unit and we'll crimp on one of our heat shrink ring terminals and we'll place that over the terminal in our junction box that has the blue wire from our seven way going to it, it's also the terminal with the blue dot over it. We'll measure off how much of our black wire we're gonna need to connect to the black terminal from our HydraStar unit, cut off the excess, and we'll strip back some insulation, we'll crimp on a ring terminal, and measure off how much wire we need from the white wire from the HydraStar unit, strip back some insulation, and you'll crimp on a terminal, place that over the stud with the white dot, the short strand of white wire that we passed through for our ground we'll strip back some insulation and we'll crimp on a terminal there, place that over the stud as well.Now we'll take the white wire from our breakaway kit, measure off how much we're gonna need here, strip back some insulation, and we'll crimp on the ring terminal there, place that over the stud too. Now we'll take the black wire from the breakaway kit, measure off what we're gonna need, cut off the excess, strip back some insulation, and we'll crimp on one of our ring terminals. Now just like we did before we'll shrink down all of our ring terminals with the heat gun.Now that we have all of our ring terminals heat shrinked inside for our white terminal, our black terminal, our blue terminal, we can install the nuts. The white terminal, this is our ground, the black terminal that's our constant 12 volt power, the blue that is the electric trailer brake output from our truck, this is where the HydraStar unit will get its signal to operate from the brake controller inside of our truck. We'll also put a nut over the yellow terminal, we're not attaching any other wires here just the wire from our seven way connector. This is for the reverse output signal from our truck. If you have reverse lights on your trailer they would hook in here.Now we need to work on hooking up our trailer's light circuits to our three terminals that are left, I have a red one, a green one, and a brown one. The brown one is for our trailer's right turn signal and right brake light and that gets our green wire. We'll separate our green wire and all this wiring here was already on our trailer. We'll measure off how much we're gonna need, cut off the excess, strip back some insulation, and we'll crimp on one of our small diameter heat shrink ring terminals. Now we're going to use this green terminal here, this is for our taillights and running lights and that'll get the brown wires.We'll separate our other brown wire from this yellow wire here, measure off what we're gonna need, cut off the excess, strip back insulation from both those brown wires, and we'll twist these two wires together and we'll crimp on one of our larger diameter yellow ring terminals to those two wires and that leaves us with our yellow wire for our left turn signal and our left brake light. That'll go to the red terminal here, cut off our excess, strip back the insulation, take one of our remaining ring terminals, and we'll crimp that into place. Now we'll use a heat gun and we'll shrink down our terminals. Okay with those all shrunk down now we'll place them over the proper studs and we'll install our nuts. Okay now that we have all of our wiring connections made inside of our junction box we can install our grommets in the locations where wires can pass through that we're not using so we have one on this side and one on the backside, then we can install the lid now.Now the short white wire that we added for our ground that came with our kit we'll strip off some insulation from the other end of it and we'll crimp on the final ring terminal that comes with the kit and we'll shrink down the insulation. Now this ring terminal needs to be attached to the frame of our trailer and this will ground all of our wiring that we've installed. We're gonna mark out a section in our frame where we can drill a hole for it then we'll drill a pilot hole. With our pilot hole made we'll now secure the ring terminal in place with the self tapping screw.Now the blue wire from our breakaway battery and the yellow wire from our HydraStar unit these need to connect to the wires on our breakaway switch. It doesn't matter which wire connects to which on this, it senses the switch once this pin is pulled it closes the circuit so it doesn't matter how you connect this. As you can see we're not gonna have enough wire to do this so we will have to supply some of our own wire. If you need to pick up some wire on our website you can pick it up as part number 12-1-1 for 12 gauge wire, it's sold by the foot.We'll start by stripping off some insulation from one of the wires, now because we are extending our wires we are gonna need some more butt connectors. These are still heat shrink butt connectors, these are for 14 to 16 gauge wires, they will work on 10 to 12 gauge wires as well, you can pick these up on our website if you need some. Crimp that on, take our extra wire that we have, strip off some insulation, slip it in the other end of the butt connector, and we'll crimp that into place. Measure off how much we're gonna need, cut off the excess, strip back some insulation, crimp on another butt connector, take one of the wires from our breakaway, strip off some insulation, stick that in the other end, and we'll crimp that down. Now we'll repeat the same process for the other wire. With all of our connections made we'll shrink down those connectors with our heat gun.With all of our connections made we went ahead and used the provided wire loom to help conceal our wiring and give us a nice clean look. Now with our wire loom we're gonna want to secure this to our trailer, now in order to secure a wire loom to our trailer we have these zip tie attachment points that have doubled sided tape on the back of them. These come with our kit, we'll take some soapy water or rubbing alcohol and we'll clean off our frame where we're going to stick our attachment points this way they have a better chance of adhering well. The zip tie will go through it, wrap around the wire loom, and we'll cut off our excess zip ties. We went ahead and repeated the same process just to secure the rest of the wire loom to the trailer so we don't snag it on anything and give us a nice clean look.Now we need to locate our brake line that goes to the back, in our case ours is right here going into a reverse lockout solenoid and we'll disconnect this brake line. Okay we have our brake line where we have easy access to our fitting knob, we need to connect this fitting to the fitting on our actuator. It's not gonna be long enough so we're gonna use a flexible rubber hose which we have available on our website in order to make this connection. Now depending on your application you may need a different length than what we're using, we have many different options available for you so just use the search feature on our website and search for the length that you need. We'll take the female end and we'll thread it onto the male end and we'll snug that down. Now we'll remove the plug from our actuator, place in the fitting from our brake hose, screw it into place, and we'll snug it down.Now we need to fill our reservoir with fluid, take the cap off, we'll use a fresh, unopened bottle of brake fluid and we'll fill it up. With it full we'll replace the cap and we'll begin the bleeding process. Okay now we'll take the yellow cap off the bleeder screw on our actuator, now we have access to the top of our bleeder on the nut. We'll take a wrench, stick it over the nut, replace a container with a hose on it to catch our brake fluid on that. Now we have two ways of bleeding our brakes, we can hook up to our vehicle and have someone operate the brake controller manual override inside the vehicle or we can have someone pull our breakaway pin.We'll go ahead and pull the pin now and we'll crack open the bleeder screw and we'll close it, reinstall the pin. What we're looking for is clean fluid coming out of our hose with no air bubbles, we'll repeat this process a couple of times. Go ahead. With the clean fluid coming out we'll pull the hose off, reinstall our cap, and double check our fluid level, topping it off as necessary. We'll replace the cap. Now we'll go back and bleed the brakes themselves with the bleeder screws on our calipers starting with the one furthest away from our actuator and working our way towards the front. Okay we're now ready to have the breakaway pin pulled again, we'll open our bleeder, and we'll repeat this process until we have nice clean fluid coming through. We'll do this on all of our wheels.That completes our look at the HydraStar Marine Electric Over Hydraulic Actuator with Breakaway and Seven Way RV Harness, rated at 1,600 PSI, this is part number HS381-9067.

Customer Reviews

HydraStar Marine Electric Over Hydraulic Actuator w/ Breakaway and 7-Way RV Harness - 1,600 psi - HS381-9067

Average Customer Rating:  4.8 out of 5 stars   (16 Customer Reviews)

Vented, marine-grade aluminum electric-hydraulic actuator lets you use your brake controller (sold separately) to activate your trailer's hydraulic disc brakes. Includes wiring, 7-way harness, and breakaway. Brake lines sold separately.

- HS381-9067

I waited several months after the purchase to write a review. This was a great addition to my boat trailer and worth every cent. I have driven hundreds of miles this year with the trailer and this product does make a huge difference with trailer stopping power and control. I tow a 24ft cabin cruiser on the interstate with crosswinds and semi-trucks that would cause the trailer to sway a little, it was very convenient and reassuring to able to engage the trailer brake to help that out the sway in the trailer. The video provided a lot of help and was easy to follow. Install took a couple of hours, the hardest thing was finding a brake line connector in stock from the local auto parts stores. Plus this makes bleeding the brakes super easy too! 706856

- HS381-9067

Delivered on time. Just one thing, the vent cap was damaged in freight. Easily replaceable. 433796

- HS381-9067

So far this product seems to be working excellent. Installed on my 2019 Dodge Ram 1500. Installation went very well, exactly as described on the video. Lori did an excellent job of helping me place my order and followed up with me to make sure I recieved everything I needed to complete the installation. I would recomend this product. 553142

- HS381-9067

Great product, replaced the Dexter model , and it works just as good if not better than the Dexter one. I have had this thing totally submersed in water because on my boat trailer there is no place where it doesn’t get submersed in water. Still works great, wiring and install was a breeze, I did it all the morning we left for the lake. 502418

- HS381-9067

It took a lot longer to install the unit than I thought, and I am mechanically and electrically competent. Being there is no mounting hardware I had to purchase several bolts and fasteners to securely attach everything to my trailer. The color coding on the wire from the plug is not standard with anything. I found out the hard way and had to rewire the lights, brakes, and signals. After two days of constructing and installing the bracket and unit, I finally got to test it. It works great so far and much smoother and controllable than my old surge coupler. etrailer promptly sent everything in a strong box and it arrived in only a few days to Alaska from the date I placed my order. Great so far! 422281

- HS381-9067

Awesome system. As described and makes trailering my 12k boat easy. Will never have a trailer without this system. Make sure you check your brake lines and caliper seals. This system works great and will find weak point in your system if you have one. Install was also easy, great video available for install! 739749

- HS381-9067

As described and arrived promptly. 739748

- HS381-9067

Terrific quality, fair price, excellent service. 732932

- HS381-9067

Breaking system works extremely well weather I'm pulling my dozer or empty can stop on a dime but recently have a condenser put on my truck and now my fine adjustment is messed up but that not the system 674850

- HS381-9067

The product was great, arrived in a timely manner and was complete. The installation video from etrailer.com was spot on and really well made. My only negative is that the self tapping screws which come with the kit are absolute garbage almost every one of them broke off and the heads are really too small for the size of the holes in the actuator. Recommend you drill and tap each hole and install stainless hardware toss the self tapper in the trash. 667684

- HS381-9067

This is great. Easy to install. I put mine in a trailer box to help secure it better just incase. I immediately noticed a huge difference over the surge brakes. I also pull a 5th wheel and wanted the same braking system on my boat trailer. Highly recommend. 656504

- HS381-9067

Works flawlessly. Very nice hydraulic brake kit for boat trailer. 636418

- HS381-9067

No issues with electric over hydraulic brake controller 617704

- HS381-9067

Product works very well, much better than surge brake system. Package arrived well packed. Have used etrailer numerous times, always great results! 469400

Working great, fine product
Wallace B - 01/25/2019


- HS381-9067

Etrailers catalogue provided a complete & accurate description of the 8 items purchased. Placing the order by phone was fast & efficient. Items arrived within 4 working days, no tax no shipping charge. Professional all around. 317745

The EOH braking system works perfectly. You are my supplier of choice ifwhen I need additional trailer parts on the future.
Pat M - 11/21/2017


- HS381-9067

System works great, I recommend it as a good replacement for surge brakes 314855


Ask the Experts about this Hydrastar Brake Actuator

  • Parts Needed to Convert From Electric Drum Brakes to Electric-Hydraulic Brakes on 2018 Raptor 355TS
    We have all the parts you need to swap from electric drum brakes to electric over hydraulic brakes on your 2018 Keystone Raptor 355TS. The first thing you will need are a hub and rotor disc brake kit. I was able to find that your '18 Raptor 355TS has a pair of 7,000 lb Dexter axles so you will need two of the Kodiak Disc Brake Kit - 7,000-lb Dexter Axle # K2HR758D, which are a hub with an integrated rotor. Since this kit does not come with bearings or grease seal you will need to order...
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  • Adding Electric Over Hydraulic Brakes to a 3-Axle Boat Trailer
    To switch your boat trailer from hydraulic drum brakes to electric over hydraulic disc brakes there are a few parts you will need. You will need the EOH actuator itself. What I recommend is the Hydrastar Marine Electric Over Hydraulic Actuator with Breakaway and 7-Way RV Harness # HS381-9067. You will not have to replace the brake lines or the coupler. If you can lock out the coupler (keep it from actuating in and out) that would be ideal. You will also need to have a brake controller...
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  • Recommended Weight Distribution System and Electric Over Hydraulic Actuator for Tug Boat Trailer
    I did some research and your F-150 with the combination you have is the 11,600 lbs if you have the max towing package. If you do not it drops to 10,600 lbs. The upgrades you have done to your truck are really nice so I can see why you don't want to change vehicles. What I recommend is keeping your current hitch, upgrading your weight distribution system to the Reese Steadi-Flex Weight Distribution System w/ Sway Control - Trunnion - 14K GTW, 1.4K TW # RP66561 because it will work...
    view full answer...
  • Recommended Actuator and Wiring for Boat Trailer Upgrade From Surge Brakes
    To add EOH to a surge brake trailer, you will need to add the electric components to make the actuator function. You can get the Epicord 7-Way Molded Trailer Plug with Junction Box - 10' Long # 277-000141 and then wire your actuator into that junction box. You will be able to simply connect to your current hydraulic brake lines. For your actuator, I recommend the HydraStar Vented Marine Electric Over Hydraulic Actuator for Disc Brakes - 1,600 psi # HS381-8067 or the HydraStar Vented...
    view full answer...
  • Best Brake Option For Boat Trailer With Surge Brakes That Overheat and Drag On Steep Hills
    The best option for your situation is to convert to electric over hydraulic with disc brakes because you have a brake controller to activate the brakes which gives you more adjust-ability on steep hills. Disc brakes cannot be manually adjusted however the brake controller gives you more control so the brakes do not stop as hard which should reduce the excessive heat buildup. They also have fewer moving parts compared to drum brakes so the maintenance is lower. To add electric over hydraulic...
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  • Are Kodiak Disc Brake Kits Compatible with Hydrastar 1600 PSI Electric Over Hydraulic Actuators
    Absolutely! Disc brake kit # K2HR35D is compatible with the Hydrastar 1600 psi actuators including # HBA16, # HS381-9067, # HS381-8067, and kits with lines, # CAR-HBA16-2 and # HBA16-252-82. It will also work older models as long as they were designed to be used with disc brakes.
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  • Does the HydraStar Electric Over Hydraulic Actuator Part # HBA16 Need a Separate Battery
    The HydraStar Electric Over Hydraulic Actuator part # HBA16 will receive power from the breakways switches battery. The 12 volt power circuit on the 7-way trailer connector will then be used to charge the breakaway switches battery. I have attached a photo of the electrical schematics of the actuator for you. The HydraStar Marine Electric Over Hydraulic Actuator w/ Breakaway and 7-Way RV Harness part # HS381-9067 comes with a breakaway switch and battery but if you already have a 7-way...
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  • Recommended Electric Over Hydraulic Conversion for Dutchmen Voltage 3818 Toy Hauler Triple Axle
    We do have the ability to convert your Dutchmen Voltage 3818 to Electric over Hydraulic brakes. First you will want the brake assemblies and for those, I recommend the Hydraulic Brake Kit - Uni-Servo - Free Backing - 12" - Left/Right Hand Assemblies - 5.5K to 7K # AKFBBRK-7 (one kit per axle). Then you will need brake lines like the Deluxe Hydraulic Line Kit - Tandem Axle - Drum # 9579-2 along with the Hydraulic Line Kit, 3rd Axle - Drum and Disc # 9579-01. Then I recommend the HydraStar...
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  • Parts Needed To Convert from Electric Drum to Hydraulic Disc On Trailer with 9K Axles
    In order to convert from electric drum brakes to hydraulic disc brakes on your 2017 Texas Pride Car Hauler Trailer you will need the following parts: Kodiak Disc Brake Kit part # K2HR958QD11 HydraStar Marine Electric Over Hydraulic Actuator Kit part # HS381-9067 Kodiak Hydraulic Brake Line Kit part # 24TR-BLKIT The HydraStar Actuators are a favorite here at etrailer as they have proven time and time again to be very reliable and perform extremely well.
    view full answer...
  • Can Hydraulic Surge Brake Actuator be Locked Out for Electric Brake Conversion
    The Demco Channel Tongue Trailer Coupler # DM12717 and other tongues like it are meant to be mounted on the outside of the frame. None of our couplers will fit a 3-1/2" frame so it would be better (and more cost-effective) to just lock out your older hydraulic coupler. We do have everything that you need to convert your trailer from hydraulic to electric brakes. I have attached a helpful article that shows everything you need. If you let me know what size axle(s) you have I can make...
    view full answer...
  • Parts Needed to Install EOH Disc Brakes on Triple 7K Axle Trailer
    We can help you with the components you will need to install electric-over-hydraulic (EOH) disc brakes on your triple axle trailer. We even have a help article that outlines each of the considerations to keep in mind as you plan out the project. I also linked our main page for 7K hub-and-rotor disc brake kits. A new hub/rotor needs to use the same bearings as the hub/drum it replaces in order to fit on your spindles. You'll notice that pricing of the disc brake kits shown varies depending...
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  • How Long Is the Warranty On An Electric Over Hydraulic Actuator for Disc Brakes
    The HydraStar Vented Marine Electric Over Hydraulic Actuator for Disc Brakes part # HS381-8067 which is what comes with the HydraStar Marine Electric Over Hydraulic Actuator w/ Breakaway and 7-Way RV Harness part # HS381-9067 has a two year warranty. This is actually one of the highest warranty periods that is offered for an electric over hydraulic actuator. There are a few other options for disc brakes which I have attached for you below along with the warranty period. Dexter DX Series...
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  • Changing Brakes from Hydraulic to Electric over Hydraulic on a Boat Trailer
    There are 2 ways to actuate hydraulic brakes; by either using a surge brake actuator coupler or an electric over hydraulic actuator. A surge brake actuator coupler actuates the brakes by mechanically compressing the master cylinder inside the actuator and applying pressure to the brakes. An electric over hydraulic actuator does the same thing, except it uses the electrical pulse from a brake controller to tell the electric over hydraulic actuator pump when to apply the pressure. If you...
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  • Recommended Surge Brake Conversion to Electric Over Hydraulic System with Disc Brakes
    The best braking system you can have between your vehicle and your boat trailer is an Electric Over Hydraulic system with disc brakes. This will give you the best functional braking as well as the most controlled braking. If you are switching systems it is best to do it all at the same time to have compatible components. If you want to go that route, I've attached an article to give you all the components needed as well as the reasoning. My recommendation is to start with the HydraStar...
    view full answer...
  • Electric Over Hydraulic Disc Kit Recommendation for 2006 Zieman Boat Trailer with Surge Brakes
    What you need first is an electric over hydraulic actuator which will allow you to activate the current hydraulic disk brakes you have. Your current brake assemblies and lines will work fine with this. The kit you need that comes with everything you'd need is the Hydrastar part # HS381-9067. Hydrastar actuators are the favorite here among our installers as they work the best and are the most reliable. You can lock out your surge actuator by running a bolt through the two pieces as that's...
    view full answer...
  • HydraStar Actuator Breakaway Kit Option
    If you wanted to order the HydraStar # HBA16 with a breakaway kit you would instead want the part # HS381-9067 which also comes with wiring and a junction box. Otherwise the breakaway battery part # 34-285 would work well as it has more than the needed amp rating.
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  • Parts Needed to Add Electric Over Hydraulic Disc Brakes to a Toy Hauler with Three 7K Axles
    It sounds like you are looking to convert the hydraulic drum brakes on your trailer to hydraulic disc brakes through the use of an electric over hydraulic actuator. If this is the case then you will need a disc brake assembly for each axle, electric over hydraulic actuator, breakaway kit, 7-way trailer connector, and brake controller. For a disc brake assembly, I recommend the Kodiak Disc Brake Kit part # K2HR712 which contains e-coated 13" hub/rotors with stainless steel mounting hardware...
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  • Disc Brake and Actuator Kit Recommendation for 2016 Grand Design Momentum 397th
    Your trailer has 7k Lippert axles on it so the disc brake kit you would need is the three sets of # K2HR712D for the disc/rotor and caliper kits. This won't be super cheap but it will give you the best option for converting to disc. For an electric over hydraulic actuator kit you then would want the part # HS381-9067 which will give you everything needed except for brake lines. For that you then would want the part # HS496-253.
    view full answer...
  • Electric Drum and Hydraulic Drum to Disc Brake Conversion Kits
    I am not sure if you are looking to convert from an electric drum brake to a hydraulic disc brake or from a hydraulic drum brake to a hydraulic disc brake but I will provide my recommendations for each option below. Electric Drum to Hydraulic Disc: Kodiak Disc Brake Kit part # K2HR526D (6 on 5-1/2") HydraStar Electric Over Hydraulic Actuator Kit part # HBA16-252-82 (Single/Tandem Axles) Hydraulic Drum to Hydraulic Disc: Kodiak Disc Brake Kit part # K2HR526D (6 on 5-1/2") HydraStar...
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  • Hydrastar Electric Over Hydraulic Brake Kit Recommendation with Single Axle Brake Lines
    Since you have a single brake axle your best option would be to go with the HydraStar EOH Kit part # HS381-9067 which includes everything but the brake lines and then from there use the from Demco # DM5424 to supply the single axle line kit.
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  • Parts Needed to Add Brakes to a 3,000 lb Single Axle Trailer
    I recommend using an electric-over-hydraulic braking system for your 2013 Audi Q5 and boat trailer. It uses less electrical wires on the trailer which is great since it will come in contact will water fairly frequently. The parts that you will need are: Kodiak Disc Brake Kit - # K2HR35D Bearing Kit - # BK2-100 Kodiak Hydraulic Brake Line Kit - # 18SI-BLKIT HydraStar Marine EoH Actuator with Breakaway and 7-Way Harness - # HS381-9067 This is everything that you will need on your...
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  • Electric Over Hydraulic Brakes, Leaf Springs, Bearings, Hardware, & Brake Lines for Dexter 7K Axles
    Since the ProLube kit # XLPROLUBE2440KIT is only rated for use on 5,200 to 6,000 pound axles I do not recommend using it for 7,000 pound axles. Grease would be better for marine applications since a hub full of grease repels water and an oil bath hub could just let the water set on top. The correct grease seal for disc brake kit # K2HR712D is # RG06-070. It does have an inner diameter of 2.25 inches and the outer diameter at 3.376 inches will fit the hub in the disc brake kit. Spring...
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  • Can Boat Drum Surge Brakes be Converted to Electric Over Hydraulic Disc Brakes
    We will have all the parts you need, but first in order to pick out the correct kit with hubs that will fit the spindles you have you will need to know what spindles you have. You can do this by getting the bearing numbers off of the bearings of the hub, use calipers to get exact measurements of the spindle, or if you know the brand and capacity of your axles that can be very helpful as well. If you check out the link I attached you will see the entire process of adding electric over...
    view full answer...
  • Everything Needed to Install Electric Over Hydraulic Disc Brakes on Trailer with 3,500 lb Axle
    I can help you pick out the parts you would need and make it as simple as possible, but there isn't a single axle electric over hydraulic kit that includes everything. You would want to start the part # HS381-9067 which comes with the nicest actuator around, a breakaway kit, junction box and the needed wiring. For the brake components you would want the part # K2R35D for a 3,500 lb kit unless the trailer will be seeing saltwater. In that case you would want the # K2R35S instead. For...
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  • Is Prodigy P3 Brake Controller Compatible with Electric Over Hydraulic Brakes
    Your Prodigy P3 brake controller part # 90195 is compatible with electric over hydraulic brake actuators and would not require any adapters. You would just need to put the controller in EOH mode. The # HBA16 would be the correct Hydrastar actuator to use. This kit would work well on your trailer that weighs between 3,500 and 4,000 lbs. I attached a link to a page that has everything you would need to know about adding EOH brakes to a trailer. A better kit for the actuator would be...
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  • Availability of HydraStar Disc Brake Kit for Drum Brakes
    There is a drum brake version of the part # HS381-9067 that you referenced. For that you would want the part # HS381-9066. The big difference between these kits is the pressure rating. Disc brakes require a higher psi at 1,600 psi whereas the part # HS381-9066 is lower at 1,200 psi.
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  • Best A-Frame Disc Brake Trailer Coupler Actuator
    I do have an option for you but there is not a version of the Titan Zinc-Plated A-Frame Brake Actuator part # T2492800 that is rated for use on trailers with disc brakes. The only a-frame trailer coupler we do offer for use with disc brakes is the Demco Hydraulic Brake Actuator w/ Lockout part # DM8105422 therefore this is what I recommend you use. In order to use this coupler with a 2" hitch ball you will also need the Demco Trailer Coupler part # DM07678-97. The Demco coupler will...
    view full answer...
  • Electric Over Hydraulic Actuator Recommendation for Trailer with Hydraulic Disc Brakes
    There is a way to actuate your hydraulic disc brakes electronically that will give you the power of hydraulic brakes and the flexibility and adjustability of electric brakes. What you'd need is an electric over hydraulic actuator. This installs on the tongue of your trailer and allows a brake controller installed in your tow vehicle to control the hydraulic pressure. This is the best all-around trailer braking solution. Our most reliable/best kit is the Hydrastar # HS381-9067 which comes...
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  • Electric Over Hydraulic Actuator Recommendation for Converting from Surge Brakes
    Locking out your UFP A160 by welding the two pieces is one way to convert to an electric over hydraulic actuator. This way you don't have to replace the coupler. Nothing we offer will fit in that housing but we do have great options. For a kit that includes everything you'd need you'd want the part # HS381-9067. This is the actuator plus all of the wiring needed. The Hydrastar kits like this are our installers favorite as they perform the best and are the most reliable.
    view full answer...

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Info for this part was:

Edited by:
Lindsey S
Expert Research:
Michael H
Expert Research:
Jameson C
Expert Research:
Adam R
Installed by:
Jeff D
Installed by:
Randy B
Video Edited:
Joshua S
Video Edited:
Kathleen M
Updated by:
Sarah W
Written by:
Amanda M
Test Fit:
Brent H

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