This Hydrastar actuator delivers up to 1,600 psi of hydraulic pressure the moment you hit the brakes. Because it’s electric over hydraulic, the signal comes straight from your in-cab brake controller instead of waiting for trailer movement. That means no delay and no push against the hitch—just smooth, proportional braking every time. It’s a big upgrade from surge couplers and keeps multi-axle setups steady and responsive.
With a full 32-oz reservoir, this actuator has plenty of fluid for long brake lines and larger trailer setups. The translucent tank lets you check levels at a glance, and the built-in bleeder screw makes it easy to flush air from the system. It uses standard DOT 3 or 4 brake fluid (sold separately), so maintenance stays simple no matter where you tow.
The durable extruded aluminum body stands up to corrosion, which makes it well suited for boat trailers or rigs that see wet or salty conditions. The sealed design keeps out water and debris, while the electronic proportional pressure valve ensures every stop is smooth and consistent.
The actuator ties directly into your existing electric brake controller through a 7-way connector (sold separately). You can adjust braking intensity right from your cab or use the manual override to engage the trailer brakes on demand—even when reversing down a ramp or backing into a tight space.
Installation is simple—mount it on the trailer frame and connect to your wiring and hydraulic lines using the 3/16" port. It runs on 12V DC power and works with any standard 5-amp-hour breakaway kit (sold separately). Once installed, you’ll have a reliable electric-over-hydraulic system that’s fast, quiet, and built for years of towing performance.
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.
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Hi everybody. Andy here with etrailer.com. Let's take a look at this Hydrostar electric over hydraulic actuator for your disc brakes. Now this is going to work with your single tandem and triple axle trailers with drum brakes and this is going to install on your trailer frame and connect to your trailer's wiring and hydraulic brake lines. And of course those are sold separately. This Hydrostar electrical over hydraulic trailer brake actuator applies pressure to your trailer's hydraulic brake system in response to the electrical signals sent from your end cap brake controller, and 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.
This has a maximum output pressure of 1,600 PSI. As you probably know, a seven-way trailer connector is needed to transmit the signal from your brake controller and of course that connector is sold separately. This actuator has improved functionality when compared with surge brake couplers. This is going to give you a faster response time. Trailer brakes are triggered when you apply the brakes in a tow vehicle as opposed to when the trailer pushes against the hitch ball.
So there will be no need to manually lock out the brakes when you back up. The trailer brakes can be intentionally activated when you reverse and the manual override on your brake controller can be activated, as I mentioned, so you can engage the trailer brakes without having to apply your vehicle's brakes. The electronic proportional pressure valve is going to ensure that braking is smooth and effective. As you've noticed, this does feature a huge reservoir, which is going to be great for trailers with long brake lines that need high volumes of brake fluid. This translucent tank is going to let you check the fluid levels at a glance and the fluid capacity is 32 ounces.
DOT three or four brake fluid is required and the brake fluid is not included with this. A built-in bleeder screw is going to let you easily flush air out of the brake lines. The hydraulic port size is three sixteens of an inch rather, again, three sixteens of an inch. And this is going to be compatible with any standard five amp hour battery breakaway kit. And that breakaway kit is sold separately.
And in case you're not familiar with the colors here on these wires, their functionality. Lemme just go through 'em real quick. Lemme put this into frame so you can see. So the black wire is going to be for your 12 volt power, and then the blue wire here is going to be for your brake controller. The yellow wire is going to be for breakaway, and then the white wire is going to be for ground. This is made here in the USA of extruded aluminum, so this is gonna be very durable. It's going to be corrosion resistant. And then let me go over some measurements with you. Let me begin by looking at the length first. So I'm just gonna go ahead and tilt this and measure this here at the longest points. So looking at the overall length, we are sitting right about 11 and three quarters inches long. And then here at the widest point we're sitting right at three inches wide. And then the overall height, we are pretty close to almost 11 inches, but if you wanna get technical about it, I'm gonna say 10 and seven eighths inches tall. Now this Hydrostar electric over hydraulic brake actuator will give you years of trailer stopping performance, but you do wanna make sure that you do not power wash the actuator or take it through a commercial car wash. High pressure water may damage the seals on this actuator, just so you're aware of that. Well, I think that's gonna wrap up our brief look today. I do hope that our time together was helpful for you. Again, my name is Andy. Thank you for joining me.
Ratings & Reviews
I just received eoh trailer brake actuator. I will be installing it soon on my triaxle boat trailer, packaging is in good condition, so the actuator should work as intended. Service is outstanding as usual, shipping was excellent. If the Canadian dollar was i stronger i would certainly make more purchases from E-trailer. Thank you
I purchased the HydraStar Electric over hydraulic actuator for disc brakes. I have been very happy with this purchase. Product arrived very quickly . Instructions were clear and installation went smoothly. Brake system is working great for me on my equipment trailer.
Best service, knowledgeable people, always very friendly
I was amazed at the excellent and quick responses I got from the team at trailer. I was spending a significant amount of money and have some good brake (ASE) credentials although I have been retired for years I was a little apprehensive at making the change. Bottom line is the conversion from RV electric brakes to electric over hydraulic disk brakes went well and it works as I had hoped. Thanks to all who helped me.
my customer liked everything about it and to date has no issues
I have a 2015 GMC Sierra 2500HD Diesel, towing a 2017 Pinnacle 36FBTS 5th. wheel. The Pinnacle has a standard drum braking system. On a long trip this year I cracked both rotors on my truck from over heating related to the Pinnacle's drum brakes failing to fully provide proper stopping.
I decided no more, and after much review I replaced the factory drum brakes with the Kodiak Discbrake system. (my first time ever doing something like this) In addition, one of the key items for me was a way not to replace my on-board factory trailer brake controller, (did not want to use an aftermarket product, that would diminish the interior look ) thus I also added the control Adapter Module that enabled me to use the factory installed brake controller. With all this change I decided to also go ahead and add a separate brake away battery. Everything I just described are shown in the attached photos.
I found eTrailer extremely helpful in answering questions, although I did not have a lot of questions since their online videos proved most helpful.
All parts of the Kodiak system worked fantastic following a 2500 mile trip. The improved braking is superior, and I did not need to replace my on board controller, but continued to use it by installing the control adapter. The disc brake picture is one of the disc brakes that I examined following our trip...all in perfect shape with everything working great for the entire trip.
Arrived with no issues and in a timely manner.
Got the order fast
Nice stuff
Will install them in two weeks
Thank you etrailer
Really nice people working there
It was the best upgrade for a new brake system I was replacing the old electric brake!
Super quick shipping!
Kodiak disk brakes on a 95 EBY stock trailer.
Made a real trailer out of it...
JK...
great service and fast shipping
After a year of heavy use with the Hydrastar Actuator, It has performed flawlessly. Very happy with the upgrade.
Great selection. And prices
I have put three on these on different trailers and they work great!! They install easily and stop on a dime!! I highly recommend the purchase of the optional HBA-CAM. All the newer trucks can be a little tempromental with the intergrated brake control box. I have an "09" GMC 3500HD
The HydraStar unit worked fine, easy to install and hook up.
I hauled several 10 ton loads of hay with no problems, after replacing a brake controller that was defective, I got another controller that was supposed to be compatible with electric/hydraulic brakes but wasn't, a newer one of the same model was compatible.
E-Trailer lived up to their slogan, great products,low prices and they have good service too.
Actuator has worked flawlessly for a year now on our 27 ft. travel trailer. Too bad I didn't get the correct sized brake line with the parts; had to wait for over a week for the replacement. And the break away pin that came with the kit broke while I tried pulling it out before I even installed it. Contacted etrailer and they said a new one would be sent to me. I'm still waiting after a year!
I've been using this brake controller with a disc brake conversion I got from Kodiak Trailer Brakes for about a year and the results have been fantastic. Prior to doing the disk conversion, I'd been through about 3 sets of the old electric drum brakes on my 18,000 lb. dual axle toy hauler and I'll never use drums again.
The stopping distance is noticeably shorter and I anticipate the maintenance to be super simple since they are discs. The electric controller takes some getting used to since there's about a 1-1.5 second delay between hitting the pedal and the brakes engaging. That can be a little unnerving until you get used to the fact that when the brakes come on, the REALLY come on.
After owning my toy hauler for ~10 years, this is easily the most important modification I've done. I will be stripping off brand new drum brakes on my next trailer and replacing them with discs before even the first trip.
Couldn't be happier with this brake system along with my Kodiak disc brakes. System works perfect.
Was a great tease, received box 4 of 4 and had to wait until Monday for the rest to arrive, the boxes were a bit hammered, and when a caliper mount bolt fell out I was worried how many other bolts had gotten lost, but everything was there. Service was great, free shipping, these were heavy boxes, and they are tough to pack well so they don't pop open. Thanks to the order staff and especially Sammi G for getting my order straightened out from my miss ordered parts, will be ordering my trailer parts from them again!
Ordered the HBA16 to install on 2013 Dutchmen Rubicon 2900 TH with 7K Lippert axles, feeding the Kodiak Disc Brakes also purchased from etrailer. Unit was received with out any problems, installed and worked as advertised. The only real issue I had was prior to the order finding out for sure if this Actuator would work on my 2014 F-350 with or without the HBA-CAM. Once I received the HBA-16 the documents that came with it from Cargo Towing solutions provided me with another resource to verify what my truck would need. I contacted Nick Ruehlman with Cargo Towing Solutions and he assured me the HBA16 would work on 2014 F-350's with built in controller without the HBA-CAM. Installation was done by a brake tech and went in without any problems. etrailer customer support was very helpful in completing this project. Brakes are outstanding now that the electric's disc's are out.
Excellent service, exceptional shipping speed. One tab was bent when received but no other damage was apparent. I straightened the aluminum in a bench vise and will have it installed..
Just received - shipment speed was awesome. Ordered Friday am, in hand Monday PM.
Will update after installation.
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