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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.
Customer Satisfaction Score:
94% were satisfied with this product
6% of customers were not satisfied
Ratings & Reviews
Larryd
9/15/2015
The HBA16 is still performing well after 5K miles. Great product.
Darrin G.
4/23/2019
This has been the best upgrade hands down that I could have done, and Im sure when it comes to stopping quickly, there is no better choice than a hydraulic electric disk brake system
Eddie
7/1/2019
Love love this brake system, going to put one on my other trailer I’m restoring.
Laura E.
5/31/2017
Thanks for your business and your review, Chris! For your reference, the # HBA-CAM is a required rather than optional add-on for 2007-2015 Chevy and GMC trucks and will not work with the OEM factory-installed brake controller.
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Morris G.
7/26/2021
Working great as well as it did since installation
Roger F.
11/29/2017
My brakes are working just as expected and hoped for. The real good news and the thing I remember about this project was how helpful the trailer folks were.
Billy K.
8/28/2018
Unit it working well. I am very happy and satisfied with this unit. Thank you
Michael
5/9/2020
The actuator worked great last year traveled over 5000 miles with it. As of late last fall my boat was stored on my trailer and because of covid19 the marina here on the east coast of Quebec wont open for another 6 weeks. The actuator was wrapped in plastic to protect it from the harsh winter here close to the ocean. I expect and need it work as it my trailer has to be certified road worthy to pull it on the public hwy. I will give you an up date in a couple of months. thks
Thomas M.
1/26/2022
It should not take that long for your electric over hydraulic brakes to react. You will want to bleed your brakes again to make sure that there is no air in the system. Also, if you an OEM brake controller you will need to replace that with a brake controller that is designed to work with electric over hydraulic systems, like the Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional Part # 90195.
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Condition: Badly Dinged
Notes: The cap is cracked/broken. Otherwise unused.
Info for this part was:
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Patrick
8/22/2025
Works exactly as it should, electric over hydraulic disc brakes on a three axle aluminum 13k trailer.