Electric Over Hydraulic Brakes

Crazy Or Genius, They Work

By Pat Piper

Control from the Cab

The other essential part of electric over hydraulic is the cab controller, an instrument on or around the dashboard that can be adjusted to the conditions outside. Some controllers are numbered so a setting of 3 or 4 is used when the boat isn't on the trailer, while a setting of 8 is used when the boat is being towed. Each driver can set the sensitivity of the trailer brakes to their liking. A lighter setting uses more of the truck brake to stop both tow vehicle and trailer.

Photo of a Titan electric brake over a hydraulic brake
Electric over hydraulic brakes include the actuator (left), a magnet and filter for the brake controller (center), and a battery box containing a 12-volt, 5-amp battery for the safety breakaway system.

Cab controller compatibility can be an issue between the EOH brake manufacturer, the trailer manufacturer (if the EOH is installed by the factory), and the model/year of the tow vehicle. Some controllers that are part of a tow vehicle package may not work with the trailer brake system. Magic Tilt's Tony D'Ippolito uses this example to make that point: "Factory-installed brake controllers in a tow vehicle package use a digital signal while the trailer's electric over hydraulic system sometimes uses an analog system. That's the cause of incompatibility so boat owners need to be aware of this if they're looking at this system." Magic Tilt says if they install an EOH braking system (and they use the Carlisle Hydrastar actuator), it's compatible with any tow vehicle. Other EOH manufacturers, Dexter for one, say their actuators won't work with GM products. In some cases, an added converter is used to connect the truck with the trailer's system. Bottom line: If you're going to be in the market for this brake system, it's important to ask about controller compatibility.

EOH vs. Surge

Electric over hydraulic fans — and there are many — are quick to point out its advantage over surge brakes when the topic turns to something every trailer boater does: backing down the ramp to launch the boat. With EOH, the tow vehicle brakes and the trailer brakes are engaged at the same time, whereas with hydraulic surge brakes, braking the tow vehicle while in reverse does not activate the trailer brakes. Remember, the surge system only activates the trailer brakes when the trailer moves toward the tow vehicle, and that's not going to happen backing down a boat ramp.

This has also been an issue when going down a hill. Some surge brake owners have said gravity going downhill can activate the brakes. There's also that "clunk" one sometimes hears, and feels, when the trailer moves forward as the tow vehicle slows down with the hydraulic surge system. That doesn't happen with electric over hydraulic because both truck and trailer brake at the same time.

The downside to EOH is cost: While the price has dropped over recent years, it's still in the $2,000-$3,000 neighborhood to make the change, depending on truck, trailer, and brake manufacturer. When EOH is installed as part of a package, the expense is less painful. "Electric over hydraulic wasn't a feature I thought about," admits Jim Favors. "It was included with the trailer that EZ Loader designed for the boat and I figured they — Ranger and EZ Loader — knew better than I did. I've got no complaints."End of story marker

This article was published in the Winter 2013 issue of Trailering Magazine.
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