M105 Trailer Brakes Won't Release ... AAAARRRRR!!!

[SasquatchSanta]

I went to move my M105 trailer this afternoon only to find the brakes wouldn't release. Both wheels are froze solid. I tried hooking up the air to see if that would release the brakes --- no luck. I also experimented with the two hand brakes --- no luck. I'm thinking when the handles are pointed up the brakes are suppose to be off.

I haven't used this trailer since last fall and I'm not very familiar with it. From what I remember, the air didn't have to be hooked up to release the brakes. I'm hoping it's something stupid that I've overlooked.

I've picked up a small air leak in the hose running from the truck to the trailer but I wouldn't think that would be causing the trouble.

Anybody got any words of wisdom???

Also, when my deuce was bobbed the trailer light pigtail was left dangling from the harnes at the back of the truck. Since it isn't mounted it's difficult to determine what is the top. It appears this thing could be plugged in several different ways. Once again --- any words of wisdom.

Thanks.

 

[M543A2]

The truck does not need to be connected to the trailer in any way to release the brakes. If it was sitting with the hand brakes set, two things are possible. The shoes might have stuck to the drums or the cables from the hand levers to the backing plates are not sliding to release. Yes, the levers up is the released position. Work the levers and see if the cables under the trailer move in and out of the housings. Try flexing the housings with your hands to get the inner cables to move in the housings.
If the levers were not set, the shoes might have been adjusted so close to the drums they stuck even though the brakes were not set. For stuck shoes, first try hitting the backing plates with a heavy hammer to jar the shoes loose. You can also back off the adjusters to get shoe clearance.
If none of that works, you will need to try to get the hubs and drums off by taking off the wheels and removing the outer hub bearing. You can then possibly get enough movement of the hub and drum assembly to break loose the shoes. I would then go ahead and remove the hub and drum to see if the shoe anchors are sticking.
Regards Marti

 

[acetomatoco]

Sledge hammer on the brake drums has proven to work in my case.

 

[Recovry4x4]

How long since towed? Mine will lock up, as designed, when the air is disconnected but as the air bleeds down, they realease. Just for the heck of it, try opening the petcock on the trailer air tank. You may need to poke into the petcock as they clog up. Of course if the trailer is the older one hose setup, this advice doesn't apply.

 

[acetomatoco]

Not too many of em had the breakaway brake set up...sorta like spring brakes without the springs.. Draining the air tank and not hooking up the two hoses will let you know for sure if it is mechanical, not air or hydraulic pressure keeping the wheels for turning.

 

[SasquatchSanta]

Today I learned that the brakes are released until I hook up the air!

Before starting the truck I jacked up each trailer wheel and found them to turn freely.

When I connected the air hose the trailer wheels siezed --- would no longer turn.

My trailer is a single hose unit and doesn't have an air tank.

I drained the air tanks on the truck --- found a little H2O but not much.

What in the heck would cause the brakes to sieze when the air is hooked up???

I've got an air leak in the trailer hose which I plan to replace as soon as I can get a new hose. For now I'm just moving the trailer around on my woods property while I cut wood. Could the air leak be causing the trouble???

Any insight is appreciated.

Thanks.

 

[Recovry4x4]

Are you hooking it up to the correct gladhand? It should be hooked to the left one on the truck (drivers side). If hooked to the right it will have air and subsequently brakes all the time.

 

[Scrounger]

The standard for 35’s, 54’s 813’s etc. is two air connections on the rear. One is the emergency side (should be painted Red) and should be on the right side. The other is the service side (can be painted yellow or blue) and should be on the left. There are shut off valves for both sides. When a vehicle is up and running and the air is build up the emergency side will have full air pressure, what ever the system puts out. The service side only should have air when the brakes in the vehicle are applied. The service side if everything is working properly should have a variable pressure that is dependent on how hard the brake pedal is applied.
The M105 trailer with single air line should be connected to the service (yellow or blue) glad hand. When one applies the brakes in the truck, air will go to a brake diaphragm that will operate a rod in the hydraulic master cylinder that applies the brakes on the trailer.
Without looking first hand I can only guess. One is that the air line from the trailer was connected to the emergency side. That would most certainly lock the brakes. Another possibility is there is some kind of air leak bleeding air to the service side. Or something was plumbed wrong on the truck.
The trailer plug is the easy one. It should be installed so that the cover hinge is at 12 o’clock. That way when a trailer plug is connected the tab on the cover can hook into a notch on the trailer plug.

 

[acetomatoco]

Excellent description..

 

[SasquatchSanta]

I really tripped over my kick-stand on this one!

I had the air plugged in on the wrong side! I had a feeling it was something simple and stupid.

The sad thing is that I knew better. I hate it when you have dumb attacks.

Anyway, thanks for the input.

 

[rmgill]

Stupid would be getting down the road 10 miles and realizing you had D-shaped rims and no tires on the trailer.

 

[bugei]

looking at the positive, the brake test was successful, and the brakes are functional, operating correctly, and fully capable of stopping the trailer

 

[Armada]

looking at the positive, the brake test was successful, and the brakes are functional, operating correctly, and fully capable of stopping the trailer

And we know that was what your intent was in the first place. You were just checking to see if the rest of us were paying attention....

 

[SasquatchSanta]

Thanks for all the great input guys.

This is a great group. You're number one on ole Santa's list.