Auxiliary Air Water Separator

[RussWhite]

I'm parked in an area of high humidity, so I decided I better check on the auxiliary air tank. Since I have no manuals or schematics of the air system I am just feeling my way around and may have some bad concepts of how things work. But for now, I think I have a small compressor located on the slide with the generator that makes up air into a small tank located in the front right bay. There seems to be a contactor and pressure switch in there that starts the compressor when the air is too low in the tank. At this time I do not know how much the compressor runs during a day as it is too quiet to hear unless you have the slide out. There is a water separator between the compressor and the check valve going into the tank. The glass bowl on the separator was very cloudy and I really was not sure if there was water in there or not. There is a solenoid vlave on the bottom of the bowl and a hose running down to the floor. I first opened the valve on the bottom of the tank and drained out a quart of water - obviously something I should have done sooner. I deselected the compressor and removed the bowl from the separator. It was full of water. I noted the drain solenoid had a 12vdc coil and then put the bowl back on and applied 12vdc to the solenoid. There was a very quiet click, but no water drained from the bowl. Maybe the compressor should be running pressurizing the bowl for water to be expelled. I am unclear at what time and how that solenoid is energized. Anyone out there with an answer to that?
I did contact Newll parts and found that the assembly or each part alone is still available - as of Feb 2011 THE WHOLE ASSEMBLY IS $171.52 NC-12302 AND THE SOLENOID IS $120.44 IS NC-705290 .
If I cannot get the automatic drain to work I think for now I will just install a generic separator and manually drain the bowl periodically using my Outlook calendar as a reminder. I have attached a picture of the separator. Russ

[rheavn]

Russ,
I had the opposite problem as you. Mine was leaking air out the tube connected to the solenoid valve. I took the air separator apart & found a fine grit in the bowl. Cleaned the separator & solenoid valve out & problem solved. During the humid times of year I see a few drops of water under the tube on the floor so I know mine is working.
The same air tank that you referred to in your post had two VERY slow air leaks on my coach. The previous owner(s) weren't diligent on emptying the water out of the air tank either. I detected them during my "war on air leaks".
I have an app't at Newell in three weeks. If someone doesn't answer your question I'll ask the question of Newell for you.

Sorry I couldn't be more help.................

[Jimg]

The valve you are referring to is a normally open valve when you add voltage the valve it closes. It also is to relieve the head pressure when it drains the water out. The hose will leak for a very short period after the compressor cycles off to drain water and air off the system.

[RussWhite]

Interesting - so you would expect that voltage would be applied to the solenoid when the compressor is running. When it stops the voltage will be turned off, the valve should open, draining any water in the bowl as the air trapped between the tank check valve and the compressor head forces the water out and then the air leaks out returning the compressor to zero head pressure and making the next start any easy one.

[Jimg]

That is exactly how it works

[RussWhite]

Following up......

Thanks Jim. Armed with the knowledge of how it should work, but knowing full well that it was not working that way, I decided to try again. I was able to disassemble the vlave. The parts were clean and the passages clear. What could be wrong? I verified the spool ( hope that is the right term ) piece was free to move and when I applied 12vdc with the vlave open it immediately was pulled to the bottom of the valve compressing its spring and sealing the hole in the bottom with its small rubber plug against the seat of the valve body. When de-energized, the spring easily forced the spool away from the seat and it looked to me like air should easily pass through ( normally open as Jim said ). But, everytime I put it back together it would pass no air in that state. So finally I would apply air pressure and watch it bubble in a small cup and saw the bubbles stop just as I tightened the two pieces of the valve body together. Hmmm, I looked some more and it appeared the the spool piece was being pushed down on the seat in the last few mm of valve body movement. On the end of the spool away from the seat end, there was a small rubber plug on that end too. I am guessing it was there to cushion the spool from smacking metal to metal when the solenoid was de-energized. But, this protruding "stopped" was contacting the other end and forcing the vavle to close when it was not supposed to. I saw no other way to make it work than to try remvoing the rubber plug. The plug was firmly in place and took a good pry with a tiny screwdriver to pop it loose. Under it was a spring. Maybe at one time that plug was free to move in its tiny hole and the spring would cushion the opening. But, at this point the spring had no use as the plug was stuck in that one position until I popped it out. I then put the valve back together and it flowed air de-energized, and did not flow air energized. The water separator is working now. Voltage it applied when the compressor is running and when setpoint it reached, the voltage drops and the air is very quicly exhausted from the bowl ( along with any water that is in there ). There is a very audible exhaust sound, similar to when the engine compressor reaches setpoint, but not nearly as loud. I am thinking a perfectly functioning valve with all its parts might not release the air quite as quickly. But I cannot see that this is a problem.
I have attached a picture of the spring and stopper I removed with a penny included for scale. I figure if it happned to me, it will be in some other Newell owner's future and maybe this thread will save them the purchase of a new valve. Russ

[chockwald]

Good information Russ. Thank you for the detailed accounting of your trouble shooting experience. This is the great thing about this site. It is an encyclopedia of this type of information!

[Jimg]

Russ,

I cannot explain what you found, and how you had to get it functioning. Age will swell rubber seats and o-rings.
The one’s I have heard are loud enough you can hear them release air not as loud as the engine air dryer but you can still hear them. Good job.
Jim

[Bob & Peggy Standeford]

Hey Gang,
I'm having the same problem with my air dryer that is up front on the curb side. When Steve and Suzy Bare were by 2 or 3 weeks ago he showed me how to drain the small tank. It had about 2 quarts of water and oil. The glass bowl is my problem. The piece of metal that's on the bottom of the glass seems to be loose, I'm afraid to remove it, but I think that's the way in to clean it up. I wanted to take the whole thing out but I'm not sure how to get it apart. Thanks in advance for your help.
Bob and Peggy,

[lbrachfe]

Bob,
I completely removed this dryer and seperator and drain the front tank every two weeks or so. Never get more than a 1/4 cup of water and no air leaks.