Frozen Brakes

[Stormcloud]

Some friends of ours are returning to Winnipeg from a rush trip to Calgary, Alberta over the weekend....roughly a 2000 mile return trip.
Their bus is an MC-2 with a 6v-71 and 4 speed; originally equipped with a mechanical hand-brake for parking. When the transmission was replaced, the shop changed the brake cans and added an air parking brake system and an air operated solenoid for selecting reverse on this transmission.
This is the first time they have used their bus in the winter with this setup, and have been battling frozen brakes the entire trip...they are almost home now (about 125 miles to go now) and are parked in our yard with the passenger rear wheel froze on.....but it could be worse! They could be stuck somewhere in the middle of Saskatchewan with no power, no cel service, and no toad.
No air dryer and no alcohol evaporator or injection kit for the air system.
I would have thought the shop that did the work may have recommended putting some sort of air drying setup on it, as they certainly had no problem spending loads of the customers money on other stuff.
We have arranged for a mobile service rig to come tomorrow morning to get them moving again, but they are gonna certainly remember this trip!

[John316]

Mark,

Sorry to hear that. Frozen brakes can be the pits. BTDT. I have no idea how their system is plumbed. However, right after we got our bus, the distribution block, right between the wheels, was frozen. Some very carefully applied heat from a small propane torch fixed it. BIG WARNING. DO NOT USE THE TORCH UNLESS YOU ARE VERY VERY CAREFUL!!!! I was glad we didn't melt anything too much, but at least we got it rolling.

Hope it goes well tomorrow. Keep us updated. And I am going to have to look up pics of a MC2. I don't think I have seen one before.

John

[lostagain]

Mark,

I would build a skirt around the bus with tarps or cardboard or plywood, and put some heat there with propane or electric.

Then, once it is thawed out, put some brake line antifreeze in the system, like in the compressor discharge hose, so they can make it home. Then look into a dryer for the next winter outing.

Take care,

JC

[oldmansax]

A torpedo heater blowing under the bus will thaw the brakes. Definitely put some air brake antifreeze in the system via the compressor discharge line. Longer term, get a 3 or 4  remote drain valves with the lanyard attached so you can drain the tanks frequently. NAPA sells them, along with heavy truck places.

TOM

[buswarrior]

I am fond of putting the brake alcohol into the air tanks by replacing the drain valve components with a male air fitting, and making up a pumping rig out of an outboard motor fuel priming bulb and hose.

Yes, they are lucky.

The trouble with thawing the system via external means, it simply re-freezes as soon as the heat is removed.

Put a quart into each tank, apply heat and then use excessive amounts of air to suck the alcohol deep into it before it tries to freeze again.

Fan the service brakes, parking brake on and off at least a half dozen times, air system up and down on the gauge a bunch of times.  All air accessories operated extensively to ensure alcohol throughout.

Prevention is the cure, air systems either need to be dry or dosed in anti-freeze BEFORE winter.

happy coaching!
buswarrior

[Stormcloud]

Yep, all good advice.  
They got mobile again this morning after the mobile service guy showed up. He slid under the bus and banged something twice, and the brakes released....( I am hearing this 3rd hand because I was away at work).
He is somewhat familiar with buses and air brakes ( he used to be a charter driver ), but he's  not that familiar with the new brake system setup on his coach.
I found an alcohol sniffer setup for him, and offered to assist in installing it next year when the weather moderates.
They did make it home today and the bus is now parked til spring.
BTW, he didn't say what the mobile service guy charged, but I would bet the bill would be the same price as the sniffer.
Funny how that goes.
In Papabus, I have an AD-9 air dryer, and an alcohol kit after that.....kind of like belt AND suspenders...

[Slow Rider]

Buswarrior,

Any chance you can provide some pics of your setup?  Would be great for anyone needing a similar rig.

Frank

[buswarrior]

Now there's an idea...

Next time I'm where the pumping rig is, I'll try to remember to get some photos.

happy coaching!
buswarrior

[gus]

Rusted parking brakes are a big problem with truck tractors in truck dealer lots. I've seen them have a mechanic slide under and beat away with a small sledge more than once. Probably what was wrong with this one although I've never had either of mine do this?

My Dodge Cummins one ton does it quite often though and I never park it with the brake on, go figure?

[Tony LEE]

Unless the water and freezing was confined to just one brake can, wouldn't a freezing problem in any of the major air brake components cause problems with both rear brakes.

[luvrbus]

There are 2 types of the alcohol systems injection and evaporation which is best ? Bendix sold the units but discouraged the use of both and now they don't service either unit with parts or the unit, I guess there is more money to be made in the air driers

[buswarrior]

Brake linings that rust into place while applied over long periods is also a busnut problem after a time in storage.

However, this doesn't happen overnight while the coach is in use. Takes many many days.

It is possible/common to get a wet lining to freeze against the drums, but that's an arctic condition problem. You may have seen that on Ice Road Truckers when they are pumping water out onto the ice to fill in the gaps, truck has to drive through, later has brakes stuck on. BTDT...

Moisture in the control valving is the usual culprit, the internals are seized by the frozen lick of moisture, and the valve does not move internally to direct air where it is intended to go.

Yes, a single parking brake refusing to release makes me put freezing further down the list.
Lack of wheel end maintenance causing stuck parts?
The defense as always is clean and lube all required parts regularly.

happy coaching!
buswarrior

[hargreaves]

It is common for the brake shoes to freeze to the drum especially in wet ereas such as Vancouver BC.   the rear brake get wet ,the driver applies the maxies. the weather gets cold and the brake shoe freezes to the drum. We used to go under with a big hammer to hammer on them to release them. Doesn't work well with low floors. Had to hook up to tow truck and rock the coach to break them free.   A real pain in the @$#.  Cheers Gerry

[bobofthenorth]

If I have been driving in cold weather I make it a point to park with the brakes OFF and leave the bus in gear to keep it from rolling away.  That way the drums and shoes get a chance to freeze before the shoes get pushed up against the drums. 

[gus]

Bob,

That doesn't work very well with Allison trans!

Blocks are the only other choice.