Trailer brakes not releasing?

[ka0tyk]

Got in a hairy spot on the ramp today. Was trying to pull out and kept spinning. Notice the trailer is just sliding to the side and won’t budge. It’s then pulling me backwards. So hooked up our other truck and ripped it out and then I could feel them unlock. It’s hydraulic but has a 5 wire to the plug. Is this an electric release of the trailer brakes when reversing? How do I troubleshoot this? I don’t want to get stuck again. My warlock/competitive has hydraulic only and has zero issues.

Also notice my abs and brake light are now on in the truck. Probably from spinning. Also driving back to the house my truck was struggling to pull the boat.

 

[BUSTI]

The 5th wire is an electric lockout to override the surge breaks when you go into reverse.

 

[BlockHead]

The break away cable may of got pulled or stepped on putting pressure on the brakes. There’s a tab up under neath you push to release them.

 

[ToMorrow44]

I’m sure it’s a surge brake system with discs so it’s a pretty simple system. The only thing that would cause the brakes to stick like that would be if the slide in the coupler (that pushes on the master cylinder) is stuck or the calipers are sticking.

As said above, the 5th wore activates a solenoid at the back of the master cylinder that either blocks fluid from going to the brakes or it opens and bleeds off fluid back to the MC. Either way, if that solenoid was sticking or malfunctioning, it wouldn’t apply pressure to the brakes.

I’ve had the slide stick on the coupler and it felt like I was towing 20k lbs, truck was working its ass off.

 

[ToMorrow44]

The break way cable may of got pulled or stepped on putting pressure on the brakes. There’s a tab up under neath you push to release them.

Good point.

Post up a picture of the coupler on your trailer.

 

[LHC Kirby]

Did you try a different prop ?
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sorry.... the other advice is better.

 

[ka0tyk]

 

[ultra26shadow]

Also check the plug on the truck. The plug contacts can get bent and not make contact with the trailer plug. Push the contacts out a little and try the plug on the trailer

 

[wet hull]

Popped fuse under your hood the tells trailer wire harness to release brakes. Its the blue wire

 

[ToMorrow44]

Also check the plug on the truck. The plug contacts can get bent and not make contact with the trailer plug. Push the contacts out a little and try the plug on the trailer

Popped fuse under your hood the tells trailer wire harness to release brakes. Its the blue wire

With a surge brake setup, he could tow around all day with the harness unplugged from the truck and the brakes would operate normal. The only thing the harness (blue wire) does for the brakes is prevents pressurized fluid from going to the brakes when the truck is in reverse (truck pushing on the coupler would otherwise activate the brakes).

Something is sticking in his system, doesn’t look like the breakaway wire is tripped, but that’s not a common setup I see too often.

 

[monkeyswrench]

Just recently had an issue with trailer doing this. Brakes were hanging and cooked bearings. Fixed and tried to bleed the system...couldn't get squat. The brake lines were run inside the frame tubing, and had started to rust. It was as if the rust flakes built themselves a one way check valve, or blocked of the passage. Weird, never seen that before. New lines fixed it though.

 

[HOOTER SLED-]

Maybe your ballasts were too full of water....

 

[lbhsbz]

Are the ABS/Brake lights still on? Do you have a scan tool that'll pull codes out of the ABS module?

Typically if both lights come on, you’ll get a power interruption code. This is almost always caused by a solder connection cracking on the EBCM relay connections to the ICB. You can cut the lid off, reflow the connections, and glue it back on instead of buying a new module for $300

 

[guest hs]

This is racist

 

[HBCraig]

Popped fuse under your hood the tells trailer wire harness to release brakes. Its the blue wire

And, in some cases, if you hooked your trailer up at night with your vehicle lights on that can blow a fuse

 

[ka0tyk]

Fuses are fine. Lights all went away when I went for a drive without the trailer. Drives fine.

I hooked up without the plug in and foolishly went up and down a hill backwards and forwards. Seems fine.

I think it’s something with the release. Maybe when I start backing up on the brakes the cylinder builds pressure and it doesn’t release. Slap the boat on there with the brakes locked up and then I’m stuck. I’ll have to grab a multimeter in town. I’m guessing the release is a simple 12v when in reverse?

 

[mobldj]

This has Happened numerous times over the years... Common occurrence
On these trailers / Quick Fix is to cut high pressure hose on the brake line with a pair of dikes & repair later !

thats what i have done,who needs brakes anyway.lol

 

[ToMorrow44]

I’ll have to grab a multimeter in town. I’m guessing the release is a simple 12v when in reverse?

Yep. This is the solenoid here on the bottom.

See if you can unbolt the breakaway lever and get a pry bar in there to manually actuate the MC. 2 different style solenoids, yours looks like the return style that bleeds off brake fluid to the MC, if so you’ll see a small rubber hose going from the solenoid to the MC. With 12v applied, you should be able to easily compress the MC all the way and all the wheels should turn freely.

The other style is just in line and closes to block fluid flow to the rest of the system. With 12v applied, the MC will be firm but should be able to turn the wheels no prob.

 

[outboard_256]

Did you figure out what the issue was and the fix? My dad's trailer has the same braking system and it randomly not releasing sounds dangerous. If its a simple part I would like to just keep one as a spare so it can be easily swapped on site.