check for condensation in air tanks?

[Bryan]

I vaguely remember the day we bought the bus when the PO was showing us everything, he mentioned something about that he checked the air tanks for condensation and released it about every 6 months. Does this sound familiar to anyone? something I should be doing? thanks!

[Cary and Don]

Yes.  There are two drains on the main tank, wet and dry side.  There is a drain on the auxiliary tank, and there is one on the tank between the rear tires. There is also a drain in the engine compartment on the line coming out of the air compressor.  If you are running a lot in humid weather conditions,  I would do it a little more often.  The main tank is really easy to drain and if it stays dry,  the other tanks will stay dryer longer.

Don and Cary

[Bryan]

Thank you! How exactly do you drain it? Is it as easy and unscrewing something? I'm a bus newbie 

[lostagain]

They should be drained every day  that you are driving the bus. That is why an air brakes course should be mandatory for anyone driving an air brakes equipped vehicle, even if it is private like a motor home.

[Cary and Don]

Most likely you will see a little handle on the bottom of the tank.  Turn it 45 degrees from where it is and you will hear the air coming out.  It could look like the drain valve on an air compressor if somebody changed out the original valve.  Make sure the valve isn't leaking after you shut it. If you haven't drained the tanks in a long time all kinds of sludge is going to come out.

Don and Cary

[gus]

If you don't have the original drain valves go to your local auto store and get cheap cable pull drain valves. Forget those electric heated ones, they never work for me!

Tanks need to be drained daily when cruising unless you are in the desert!

[Ed Hackenbruch]

I drain mine every day that i run it,....even in the desert!  So much easier to do with the cable pulls.

[Jon]

I hope those everyone understands to effectively drain moisture from a tank the tank has to be bled down to zero pressure.

If not the rush of air literally blows a hole through the collected moisture and little of that moisture is drained.

Everyone has a different use of their coach in terms of how much they drive, where they drive, etc. but for me I change air dryer cartridges every two years and I doubt if the amount of moisture I have gotten out of my tanks which are drained every 5000 miles amounts to a tablespoon worth of liquid.

[chessie4905]

   Occasionally the tank drains should be left overnight to allow any oil and sludge to completely drain out. (per service manual) Also get the manuals for your coach if you don't already have them-ebay. An air drier would make a nice addition. If your fuel tank is recessed about 1 foot on driver's side end; that is where to install it. There should be a large copper air line at top of this location with a coupler. You disconnect this line and plum the ends into the air drier. If you have the larger fuel tank, this space is taken up by the longer tank.

[gus]

jon,

I don't really agree with that. I find that air blows out water that won't drain otherwise.

If I have the problem you posted I just wait a second or two between pulls.

[Bryan]

this brings up a good point...I think a very useful tool for us newbies would be a detailed maintenance checklist with timeframes. For example, oil change, transmission fluid change, drain air tanks, etc, and how often for each? 

[chessie4905]

   Factory shop and owners manuals are the first thing to start with.

[Jon]

jon,

I don't really agree with that. I find that air blows out water that won't drain otherwise.

If I have the problem you posted I just wait a second or two between pulls.

We'll have to disagree Gus. It has been my experience that if there is anything in the wet tank, even after the pressure is zero there will be a little water / oil mix coming out. Not much, but enough to make me continue to wait until the pressure is zero before closing the valve.

[TomC]

If you have an air/water separator, you shouldn't be getting much of any water in the tanks. I drain mine maybe 2 or 3 times a year. A few second pull at full air pressure is all that is needed. Unlike what I have read, the air leaving the tank will pull the water and oil with it out the tank very quickly.
If you don't have an air/water separator, then the tanks should be drained daily. And if you don't have an air/water separator, you should install one. The cost of the air/water separator is far less then the repair of rusted air components. Both Freightliner and Western Star install air/water separators on their truck's air systems standard from the factory.  Good Luck, TomC

[Bryan]

Thanks everybody. Found the easy valve release for all 3 tanks. And yes, lots of sludge.