Driving next week without air line antifreeze or dryer heater

lostagain · February 23, 2011, 03:57:44 PM

2 buddies and I are taking my bus (the 5C) down to Laughlin, Nv. next week towing our motorcycles. (from southern BC).

There is no way to put any alcohol into the air lines, and there is no wires to the dryer purge valve heater.

I have always had either or both on buses I have driven before.

It is cold this week, not as much next week when we go, but likely still below freezing at night.

We are driving straight through (both my friends are experienced truckers), only stopping for fuel and to check the oil. We'll go the quickest way: Spokane, Wa., I.90 to Butte, Mt., then South on I.15 to Vegas.

Should I worry about the air lines freezing up?

If I run a wire to the dryer, where should I take the power from? It should only be on when the master switch is on at the dash, right?

Am I worried for nothing?

JC

bobofthenorth · February 23, 2011, 04:02:15 PM

Where is the dryer located JC? I don't have either a dryer or AF injection and I've often run in -30 weather, not happily mind you. Even in that kind of temperature my dryer is 45 to 50 degrees going down the road according to Jim Shepherd's temperature monitor in my engine compartment.

Stormcloud · February 23, 2011, 04:06:01 PM

We froze up in early January on our way south, and thats with an AD-9 dryer in the system.
We spent one night in an agricultural repair shop to thaw out, then no troubles on the rest of the trip south.

But.......

We also froze on the way back in early February. This is after I replaced the AD-9 cartridge in Yuma, AZ.

If you have been regularly draining the air tanks following use, and the air compressor is is good shape with no/few air leaks so that it doesn't work overtime, you will likely be OK.

I have discussed with my mechanic the benefits of adding an alcohol kit after my dryer; that may alleviate the problem next year. I'm also looking at replacing or rebuilding the compressor. I know it passes a bit of oil, but I didn't think it was enough to screw up the cartridge.

I guess I was wrong.

Have a great trip!

Mark

lostagain · February 23, 2011, 04:16:59 PM

Thanks guys!

The dryer (AD-9) is at the front near the front axle.

The air system is in good shape and doesn't leak more than normal. I usually drain the tanks regularly. The bus has been in my shop all winter, so it is not frozen now. I am thinking (wishfully?), that driving non stop will keep the system from freezing?

JC

Fred Mc · February 23, 2011, 04:23:51 PM

I wonder if an air system is like a water system in a house. Even though it is cold enough to freeze the pipes, if you have a minute amount of water running through it, it won't freeze. I wonder if air moving through the system will prevent any freezing.

belfert · February 23, 2011, 05:22:20 PM

My AD-9 air dryer froze up solid on me here in Minnesota. It was so plugged that the compressor couldn't move any air at all. the compressor was discharging through the safety valve on the compressor. I'm not sure how it got so much moisture inside the dryer to freeze up in the first place. The bus was parked in October and the air dryer was definitely purging then as I could hear it. When I next started the bus after weather was below freezing the compressor wasn't passing air.

It turns out my purge valve heater was the wrong voltage so it wasn't heating. The line coming into the air dryer from the compressor had a solid plug of ice in it. I removed the air dryer and ended up replacing both cartridge and the purge valve.

I had no problems driving from Minneapolis to Arcadia, FL and back in late December after the purge valve heater was working. The moral of the story is I would not drive without your purge valve heater hooked up.

buswarrior · February 23, 2011, 05:39:06 PM

I would run a temp wire to that heater and check that it has the right resistance with the multimeter.

Freezing up in your case isn't about the tanks, it is about the purge valve in the drier.

Put the wire any old place for now, powered when the coach is. Tie wrap/tape it up and do a nice job when you have time.

An air drier will work great, if it is used as directed.

That means a little electricity to the purge valve heater.

The air drier "sneezes" the accumulated water from each compressor cycle. The moisture hangs in the purge valve like a runny nose, no problem if the heater is making some warmth... sticks the purge valve if it cools to below freezing between compressor cycles.

And then you get no air past it, and get to go disabled on the road with no air reaching the tanks, and an inaccessible air drier up under the front end.

Not worth the gamble, and your buddies will have a hate on for the coach forever after that.

happy coaching!
buswarrior

Paso One · February 23, 2011, 05:48:01 PM

Quote from: lostagain on February 23, 2011, 03:57:44 PM

If I run a wire to the dryer, where should I take the power from? It should only be on when the master switch is on at the dash, right?

JC

The Bendix dryer has a thermo switch inside, when wire is attached to power it is only heating when the temperature is below 40*

I would wire it to a keyed switch so when you park it doesn't heat all night if in low temperature.

lostagain · February 23, 2011, 05:53:03 PM

OK guys and thanks...

The bus is still up on blocks, so getting under it is easy. I will run a wire to the heater tomorrow. I'll let you know how I make out.

JC

trucktramp · February 23, 2011, 10:36:56 PM

Quote from: Fred Mc on February 23, 2011, 04:23:51 PM
I wonder if an air system is like a water system in a house. Even though it is cold enough to freeze the pipes, if you have a minute amount of water running through it, it won't freeze. I wonder if air moving through the system will prevent any freezing.

From what I understand, air moving constantly through your brake system will NOT keep your system from freezing. Actually, it will possibly cause it to freeze up faster. It has to do with evaporation. The air moving over the water causes some to evaporate (this is why you feel cooler in the summer when you get wet...think sweat) causing the ambient temperature to drop making the area at the leak colder. Any water will now freeze sooner eventually causing problems not to mention the extra work that your compressor will be doing to make up for the loss of air. You would be better off with dry tanks plus a working air dryer and/or alcohol injection.

caz · February 24, 2011, 07:30:45 AM

Boy have I had experience with this issue as of late. I took this pic in Dallas the week of the Super Bowl. Needless to say I did not expect the weather.
Yep, that's supposed to be one piece

It exploded about 1:30 after I started the bus.

That said, you can open any air line and pour some air system antifreeze in there(Heet fuel treatment even works in a pinch) and just get some in the lines, you should be OK. I used the Heet stuff last Thanksgiving in Chicago when it dipped down around 17°. Couldn't access the dryer but I just pushed some in a rear line with a hose and my portable air compressor. Everything unfroze after about 15 minutes.

Good luck!

lostagain · February 24, 2011, 07:53:06 AM

Thanks caz.

I will have a bottle of air line antifreeze with me. I could put some into the hose coming off the compressor.

Today, after i get some heat going in the shop, (-18C, 0F now and going to 30 below tonight!!), I am wiring the heater on the dryer. I see by the PO's receipt that the AD9 is fairly new, but he never put a wire to it, I guess he didn't use the bus in cold weather.

I should look into installing a AF suction bottle system. It doesn't look very complex.

JC

buswarrior · February 24, 2011, 08:08:00 AM

DON'T PUT ANTIFREEZE IN AHEAD OF THE AIR DRIER.

You will turn the desiccant into mud, and it will travel, if it doesn't plug the works up, and render the purge valve seal useless.

If you feel the need, put it into the wet tank via an air fitting in the drain, an outboard fuel line squeeze bulb and some hose. No air in the tank to begin....

Get the air drier working right, and keep it working right, 365 days a year, be mindful of how you use an auxiliary compressor to air up, and a busnut has no need for air system antifreeze.

happy coaching!
buswarrior

lostagain · February 24, 2011, 08:10:11 AM

Thanks BW.

lostagain · February 24, 2011, 04:16:33 PM

Mission accomplished!

I determinned that the heater is 12V: 2.5ohm cold. Plus I took it out and it got hot right away when I applied 12V.

I could not find a 12V source that would be on with the master switch, (the bus is 24V), so I got it from a 12V stud that is hot all the time, and put a switch on the dash. So I can have it on when it's cold out, and off when above freezing. The dryer heater has a thermostat as well.

Anyway it is done, and I am at peace now

.

JC