Frozen brakes

If the trailer was not set. It should not have iced while air pressure dropped

It could be possible that you have moisture in the air tanks themselves that has frozen

If wet and going to freeze I will drag my brakes a little while going to park
I set the trailer for a few minutes to allow the truck to cool then reverse that and set the truck and release the trailer

If really concerned I will then move forward a little and then back and park leaving the trailer brakes open

 

Bet you don't miss Minnesota now. I hear actual temps of -20.

 

No I don’t but it seems I’m always in Mn or west through Montana and in it anyways

 

Ask yourself, How hard is ice in the lines/valves...?

 

If you're hearing air constantly moving, you have a valve hanging up somewhere.

You can use a torch (on the drums) but normally a good whack with a 2 lb hammer does the trick. You can hear the difference, a set brake will clunk, a free one has a slight ring to it.

And only release truck or trailer, never both, when banging drums.

 

If you can idle with your brakes released, that'll solve your problems. It will take a little bit of time, but it does work. My trailer brakes iced over last winter in Colorado. I idled a good hour and a half before the ice broke. Some truckers dump alcohol in the air line....spraying your brakes with alcohol before bad weather is good preventive maintenance.

 

@KostaN did you ever get moving?

 

You can GENTLY use a torch on the trailer brake valves. keep the flame moving and don't linger in one spot too long. Be careful of the plastic lines. You don't need any more problems.
Pay special attention to any 90 degree metal elbows.
This is where the moisture will most likely collect if it's not in the valve itself.
Do this after putting in brake line antifreeze. Make sure your red button is pushed in while doing this.
And you will hear the air flow when you hit the right spot.

 

It was -24 this morning at home.

 

IDK, idling won't unstick the shoe from the drum, and alcohol in the lines won't do it either. It's a combination water and rust on a shiny surface, that almost welds the shoe to the drum.Maybe it warmed up enough for the brakes to thaw, but a good rap or heat, you''d be on your way.