Dumbest question you've heard...draining air tanks?

I can tell you what happens sometimes when the water is not drained. They sent me up to Reno out of Las Vegas as a ride along so I could pick up a tractor and bring it back. Of course the tractor was loaded as a set so I had to make the normal stops. I go out to the yard on a Sunday morning and it's cold out. Somewhere below zero so I knew I'd have a hell of a time starting this beast that was parked outside all night. All they left me was a set of keys. I walked around until I saw a can of either, man that was lucky. I fired the truck and did the pre-trip blah, blah, blah. Everything was ready to go. I did try to drain the water and all I got was a little air coming out. You know sometimes they get a little dirty and will not close all the way or not let any air out. So I checked everything and off I went.

Just cruising down the highway with a set of trips. The air lines start to get warm and the little bit of water in the air lines started to move around. I'm watching the air gauge and the air is going down. I pull over when it's around 70 psi and try to fix the problem. Man it's cold out. I didn't know at that time what was going on so I looked for leaks. I did not find any so back in the truck I go. I now notice the air is normal. As I'm going down the road I see the air playing tricks on me. Down to low pressure, then to normal, then up to high. It finally dawn on me what it could be. A water slug just enough to block the air line when it got warm enough to move. It would move and then when it hit the very cold part of the line it would freeze again.

I made it to the first terminal where I had called the mechanic in. He was ranting and raving and I told him just hold on here. This is not my tractor, they sent me to Reno to pick it up. You want to complain to anybody you call them and ask why they haven't drained their air lines. I also told him he's lucky that the tractor stayed in the green zone for air or you would be traveling on.

He got out the little hand held torch and heated up the air lines while I held open the drain valve. A lot of water came out or what I believe is a lot of water. We finished and the truck worked perfectly from then on. Just to show whoever that water can play tricks and act in a way where you think it's ok. It can move around and cause all kinds of problems. The only way you can fix this is drain your tanks once in awhile. That's even with the air dryers installed.

 

I pull my cord for the wet tank at every stop I make. It's a habit.

 

The trailers have a large tank up near the tandems, have to crawl under there once in a while and open the valve to drain it out.

 

And of course, that is where a lot of the problem is. I'd bet that a good half of the drivers that do drain the tanks on the tractor, never look at the tanks on the trailer. After all, it will BE SOMEONE ELSE'S PROBLEM, after you drop the trailer...
Unless you are hooked to the same trailer all the time.

 

I like that statement!!!

 

"water slug" Learned something new again
Was told in school to bleed down the tanks twice in cold weather when starting up after sitting overnight.
Will have tuck this away for the future.

 

30 minutes? I hope you didn't drain all the air out.

 

Most air tanks have air driers in em nowadays so likely you won't find any water buildup anyway. I guess it wouldn't hurt tho especially if the temp is supposed to drop below freezing. Also if you're driving a POS than you'll want to add some air line anti freeze to the service line? I think it's the service line don't remember.

 

you are ahead of me, i've never even looked - lol

 

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