What You Need to Know About Reversing Trailer Solenoid Valves
People who own trailers that have hydraulic brakes may need to replace the reversing solenoid valves in case the brakes keep locking when one is reversing. Such trailer repairs/replacements should be done after selecting the best type of solenoid valves to use. This article discusses the two types of reversing solenoid valves that you will select from when performing trailer repairs.
Blocking Solenoid Valves
Blocking solenoid valves are valves that close once an electrical current activates them as you start reversing the tow vehicle when the trailer hasn't been detached. This activation prevents the brakes from engaging as you reverse. The biggest advantage of using this type of reversing solenoid valve is that you will not have to drill into the brake fluid master cylinder in order to create space for installing a return line for brake fluid. Any fluid that was in the brake lines when the valve was activated stays trapped within those lines.
However, the work that you avoid when you install this type of valve comes with a big shortcoming. The residual brake fluid in the brake lines can keep the brakes engaged in case the electrical current reached the valves when you had just braked prior to reversing. Tyre wear can take place at a higher rate as the tow vehicle forces the trailer's wheels to rotate while brake fluid is blocking their free movement. Avoid installing this type of valve in case you want to prevent this needless tyre wear.
Bleed Solenoid Valves
You also have the option installing a bleed solenoid valve in the place of the one that has failed. Bleed solenoid valves require you to drill a hole for a return line in the master cylinder in case none existed before. That return line allows brake fluid to flow out of the brake lines when the solenoid valve activates in order to disengage the braking system.
This type of valve is recommended for people who frequently reverse their trailers onto an incline. The downside of bleed solenoid valves is the time and skill needed to create a hole in the master cylinder for the return line. However, the benefits of longer tyre life outweigh the cost of creating that inlet.
Each trailer manufacturer describes the process by which any component of the braking system can be replaced or repaired. Follow those guidelines when you are repairing or replacing the reversing solenoid valve so that you don't cause more damage to the brake mechanism.