Surge Break Behavior

[Cement102]

Hi all. Been towing electric breaks my whole life, so new to surge. Have a couple questions to determine if my trailer is behaving normal. First, when I stop (red light) there is a definite yank on the truck when taking off. I start real slow to minimize, but there for sure. Fluid is full, new pads, lines bleed. Breaks dont drag or anything. I think this is all normal...?

Bigger question is when I back the boat in the drive, chalk the tires and unhitch, the piston stays compressed under no load. Is this a normal behavior, or should it re-extend?

Thanks!!

[freeheel4life]

Here's a test. Unplug your trailer plug from the truck with trailer hooked up.. Block wheels off with a couple 2x4 or other reasonable sized chocks. Then back up. If trailer backs up over the blocks and you don't feel any brakes at all you either still have air in the system or you have issues in master/actuator assembly.

You can also just do a hard braking event to compress the piston, stop, unplug harness from truck, and then back up. If you have no resistance at all from the trailer, same issue.

[UNSTUCK]

First question. Yes, the clunk you hear is normal. That is the coupler pulling out of the slide area and releasing the master cylinder.

Second, I don't believe there is any sort of return spring or anything mechanical that would cause the coupler to slide back out on its own. It just kind of floats in the position it was left in. This may explain why these types of brake systems can drag and get hot/overheat on long downhill grades.

Do the checks that freeheel mentioned. Also make sure that the ball on the brake away is not sticking way out of the cable hole. I think being just out of the hole or just visible is okay though. That is how mine has been for ever.

[Bamer]

Yes the clunk is normal and is annoying.

In the wiring harness, there is an extra wire connected to the reverse lights on the truck. When in reverse, that wire moves powers a solenoid that blocks the brake fluid from moving. This allows you to bake up. If the brake light wire is not connected and the trailer braking system is working properly, it will be very difficult to bake up, hence the test described by Freeheel4life .....

I had to replace my actuator on my previous boat because it developed a leak. There was not a spring but there was a mini shock absorber that used the brake fluid to dampen actuator movement so it does not oscillate during braking. Oscillating means truck brakes which engages the trailer brakes, trailer slows down faster than the truck, trailers brakes release and because the truck is still braking...the sequence of events rapidly repeats causing a violent cycle of trailer brakes rapidly engaging/disengaging. On that boat, if the fluid was low enough, air would get in the shock absorber and the oscillating would occur. I’ve even experienced that oscillating on my R23 trailer when empty going down a very steep grade at slow speed.


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[NICKYPOO]

I just had the entire brake system on my trailer replaced. New coupler, lines, calipers, wiring, everything. What a difference. Last year I had a rock or something puncture a line so I had no brakes. The clunk at take off was huge. I had to be real delicate with the throttle. Now, with everything new, there’s only the slightest of clunks. There’s so much pressure in the system that it pushes the coupler back out immediately and now it’s barely even noticeable. As soon as I release the coupler from the ball, the coupler pushes right out to the extended position. If the clunk is huge, and the coupler doesn’t push out when disconnected, I’d say there’s an issue.

Now in regards to the reverse solenoid, some surge systems have them, some don’t. The ones that don’t have a lockout pin that needs to be placed in the coupler to keep the brakes from engaging prior to reversing. My new system is like this and I hate it. I will be installing a reverse solenoid when I get the chance.

[teachercop]

Just replaced my solenoid. I did have to remove the coupler system and re-bleed the system,

https://www.pacifictrailers.com/prod...RoCIYcQAvD_BwE

[Jetdriver]

Make sure your fluid is topped off. It also might be a good idea for you to bleed the brakes. Pretty easy to do with two people.
I’m not sure what trailer you have or more importantly, what brake actuator you have but a bunch use UFP components.
On mine (A pretty common UFP A-60) there is a manual release tab under the assembly a couple inches from the coupler. Push this to release the brake piston. If it clicks you know the piston was compressed, if no resistance than it wasn’t.
Behind that tab you can see a circle hole, this is where you insert a flat blade screwdriver to compress the cylinder to bleed the brakes. There are how tos on you tube.
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