Here are some compromises associated with electric trailer brakes
1) Drum brakes need to be adjusted periodically to compensate for shoe lining wear – this adjustment is done mostly by “feel” and it is unlikely that the average person can get all four wheels calibrated properly
2) Drum Brake magnets tend to gradually lose their magnetic strength, causing more calibration problems and loss of braking power
3) Drum brakes are relatively complicated with many moving parts that can cause a failure and need some experience to rebuild the brake assembly
4) Drum brakes tend to accumulate corrosion faster than discs, especially in marine and snowmobile applications
Disc brakes do not have these issues to deal with and are relatively simple with fewer moving parts. Unfortunately, they are not available in an electrically actuated system like the aforementioned electric brakes. They are only available hydraulically actuated. In order to take advantage of disc technology, a new device has been developed to allow for electrically actuated disc brakes. It is called the Electric over Hydraulic Actuator. This device is nothing more than an electrically driven hydraulic pump and relief valve that is controlled by the standard cab mounted Electric Brake Controller, typically used for standard electric drum brakes.
The E/H actuator will be added to the trailer and connected electrically to the brake controller through the 7- blade RV socket on the tow vehicle bumper. Also connected in line will be a Breakaway kit with a 9 amp-hour battery that provides enough power to actuate the pump should the trailer accidentally separate from the tow vehicle while on the road. The output will be connected to the trailer hydraulic system through a standard trailer hydraulic brake line. The E/H system can handle trailers with up to 4 axles by providing 1600 psi maximum. The E/H actuator device does add some expense to the installation.
Of course, the electric brake assemblies and drums on the trailer will have to be replaced with hydraulic disc brake assemblies and brake lines.
The Electric/Hydraulic actuation system also has advantages over trailers that already have hydraulic disc brakes with a Surge Actuator.
1) The E/H actuator keeps the trailer brakes active while in reverse – with the surge actuation, the brake lines must be locked out so that the trailer can be backed up. There is no need for a brake line lock out device.
2) In hilly or mountainous areas, the surge system can incidentally engage the brakes while going down a grade; this will not happen with the E/H system
3) The tongue mounted Surge brake actuator can still be used as the trailer’s ball coupler with a small modification
The Electric/Hydraulic actuation system blends the advantages of disc brakes with the benefits of the cab mounted brake control for the safest experience in trailer towing.
The Trailer Parts Superstore carries a complete lineup of TITAN Brake-Rite E/H actuators as well as the DEXTER 1000-1600. We also carry a complete assortment of KODIAK Disc Brake assemblies for to fit most any trailer application. You can check out our complete trailer brake selection online at: http://www.easternmarine.com/em_store/trailerbrakes/