Boat trailer brake trouble

dstig1 · Sep 16, 2015

Posting this to help a friend as I am not familiar with these systems. It is a Mastercraft boat and trailer combo. The trailer is a single axle with hydraulic disc brakes (surge type brakes) in the ~5k lb range. He went to bring it in for winterizing/storage and found the brakes were dragging badly causing the wheels to get hot. Didn't go too far before turning around. He lives a couple blocks from the lake he goes to, so it never moves far except start and end of season. Brakes are definitely dragging based on some investigation he did. He took apart the surge mechanism in the tongue, and appears to be operating correctly. The only real suggestion I had was perhaps the flex lines to the calipers are swelled and restricting flow. Seen that on several cars when they got older. Other than that I do not know what to look for on this type system as I have not seen any of these before. Looking for advice or likely trouble spots to check out.

Thanks for any help!

Dave

Diamondpilot · Sep 17, 2015

Flex lines and reverse solenoid are always my starting pleace. 9 times out of 10 it's usually the flex lines.

If you are not familiar with a reverse solenoid it's a small electric solenoid placed behind the master cylinder that takes a signal (12v when tow vehicle is placed in reverse) and closes off the system preventing application of the brakes.

We are assuming here the cylinders or calipers are not frozen.

Is it a drum or disc system?

Chris