EOH Maintenance - Electric Over Hydraulic Brake Actuator

EOH Maintenance Information

Check all wiring, cabling, and connections every 12 months, ensure the following:

Insulation/coating is free of cracks, peeling, and UV damage.

Check that all plugs are free of corrosion and debris damage.

A few seconds with a medium wire brush will clean up those plugs and contacts beautifully.
If the trailer lights are flickering or the actuator is cutting in and out, give the plug a slight, gentle wiggle.

Ensure harness/cable sheath ends are covered by the plug's boot and/or firmly held in the plug's cable restraint, if present. Usually would be a screw type or a cage type.

Inspect all wire joints and splices.

Ensure solder joints are encased and watertight with no exposed copper.
- Using just electrical is not going to cut it; use glue-lined heat shrink over top, or just heat shrink.

If using terminal blocks in a junction box.

Ensure the terminal block is firmly mounted in the junction box.
- Make sure the junction block is also firmly mounted.
Check for corrosion on the terminals, and clean if necessary.
- If corrosion is present, the junction box is not watertight!
Ensure you have adequate cable stress relief in place.
- Cable glands are the way to go for water resistance and cable stress relief.

Check the length of the harness and cable for excessive droop and slack

Ensure all restraints, saddles, and fastenings are firmly fixed, holding the cable firmly.
Ensure there's not too much slack in the harness and loom along the entire length, with the exception of the trailer-to-vehicle harness interface.
- From the end of the tongue, just before the hitch, to the vehicle, you need some slack to allow for stress while turning. Typically, the length would be between 1 and 2 feet; however, check with the local road authority about the recommended length and allowable slack.

Check breakaway health

Measure battery voltages and perform tests to check they are still within the manufacturer's specifications.
If the actuator sounds like it's struggling during the first three minutes of testing, the battery may need some attention.

If left unused for extended periods or seasonal usage, cycle the pump's fluid once every 1-3 months.

Check Brake fluid level and quality every 3-6 months.

Again, you would want to do this more often in high-humidity, hot, or cold climates.
If the fluid is low, top it off. If it is frequently low, check for leaks in your hydraulic braking system.
If the fluid is extremely discoloured, the system must be flushed out.
- This can happen to new trailers due to residues and oxides in the different parts of the hydraulic system, usually left over from the manufacturing process. Over time, steel parts in the braking system will oxidize and may alter the color of the fluid.
- Constantly running the actuator with low fluid aerates the fluid, which can saturate it with moisture from the air and discolour it. To reduce the air volume in the tank, it is best to keep the fluid topped up to the brim.
- If the fluid has excessive particulates or sediments on the bottom, agitate the sediment into suspension in the fluid, then siphon out the fluid and repeat until most of the particulate matter is gone. Proceed with a complete flush out and system re-bleed.
- Check the hydraulic system for corroding parts if the fluid is discoloring or accumulating quicker than usual.

Bleed or flush the brake system every 12 to 24 months.

Again, you would want to do this more often in high-humidity climates, hot or cold.