The Hydrastar Vented Marine Electric Over Hydraulic Actuator for Drum Brakes brings the quick response of an electric system to the smooth power of hydraulics. With a maximum output pressure of 1,000 psi and a 12V DC pump, it applies your trailer’s hydraulic brakes the instant you hit the pedal—no waiting for the trailer to push against the hitch like surge setups. The electronic proportional pressure valve keeps braking smooth and consistent, so your trailer slows down at the same rate as your tow vehicle.
This actuator is made from extruded anodized aluminum, with a marine-grade gasket and stainless steel hardware that stand up to corrosion and saltwater. It’s ideal for boat trailers or any setup that lives around water. The seals keep moisture out to protect internal components, and the vented end plate releases pressure, moisture, and heat to keep things running cool and reliable even in enclosed compartments.
Unlike surge couplers that can lag or lock up when backing down ramps, this actuator responds instantly through your brake controller. You can even apply brakes in reverse when you need extra control on an incline or while maneuvering in tight spots. The manual override on your controller lets you activate the trailer brakes without using your vehicle’s brakes, which is handy when loading or during maintenance checks.
Installation is straightforward—mount it on the trailer frame with the included stainless hardware, splice into your wiring, and connect to your brake lines through the 3/16" hydraulic port. The built-in bleeder screw makes it easy to flush air from the system. It’s compatible with any standard 5-amp-hour breakaway kit (sold separately) and works for single- or tandem-axle trailers up to 7,000 lbs with drum brakes.
The vented housing prevents internal heat buildup so you can safely mount it in areas where other actuators would overheat. Every part—from its sealed electronics to its durable aluminum body—is built for years of dependable braking power in marine conditions. This Hydrastar actuator is a direct, proven way to upgrade from older surge systems to precise electric-over-hydraulic control.

Customer Satisfaction Score:
98% were satisfied with this product
2% of customers were not satisfied
Ratings & Reviews
GREAT PRODUCT
It looks very promising. Arrived early and in excellent condition. We will see how it holds up
Melisa was very helpful on the phone and promptly shipped my parts. Appreciate it very much.
Had a problem with first shipment , was resolved promptly
Unit work’s very well and was easy to install .I am looking forward to a wonderful safe trip pulling my 12,000 lb boat 600 miles north to San Juan Islands and British Columbia.
etrailer as always has what I need, ships fast, and product is "as advertised"!
A pleasure to talk to the tech's when I have questions and even go as far as calling manufacturer to verify equipment selections.
Keep up the GREAT work.
Great reliable product. It handles my 12,000 lb. boat and trailer on wet or dry roads.
I ordered the brake controller yesterday I already have it today so it was here in one day quick service I don’t have time to put it on right now but when I do I hope to let you know how it works thank you . I Purchased a titan brake controller probably five years ago and it on a cattle trailer so I didn’t use it a whole lot and the motor went out on it very quick so I was disappointed in that brand and I thought I’d try this hydrastar system hope I have better luck with it . Thanks
I installed it in just a few hours, and set it to the most aggressive setting. My wife and I have wanted one for a few years after a few close calls pulling our boat. Well, weirdly enough, this product paid for itself in the first week. A car pulled out right in front of us on a highway. I was able to avoid the crash, that if this product was not on, we would have hit. Pulling a 10 thousand lb boat, one just cannot stop on a dime doing 60 mph. The next week on the way home from the lake, a moose stepped out onto the highway, once again, was able to stop! My wife is happy as we had a few close calls and she was very happy and it was money well spent. Wished we had bought it sooner.
Well built unit that works well .
Easy install, works great. Installed a whole EOH system with this unit at the core. Excellent.
Shipping box was ripped, should of had more packing material, fortunately everything was still in the box.
Item arrived earlier than expected. Installation was easy. And now my trailer brakes work again.
a very nice woman took my order ...she said it would ship in x business days ....i said never mind that put down the phone and run and ship my order ..she laughed and said they didn't let her into the warehouse...however if she didn't pack it up herself immediately, someone else did ..i had it way before i expected it ...hydreastar product ..1sr one lasted about ten years of almost 5 days a week use on an equipment trailer ..i expect to get same service from this one ...
It working good on my M105A2 Military trailer. Thanks etrailer.
Substituted the Hydrastar unit for the surge brake actuator on my military surplus trailer. Works like a champ!
Unit works well. Packaging was good and well protected. Came with instructions that were illustrated and well written.
There was a problem with the shipping, not etrailer’s fault at all. I called etrailer and talked to one of their representatives who was very helpful and resolved the issue and followed up with me. Couldn’t ask for better service and product.
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