[rheavn]

My 110V air pump started running every 12 minutes so I knew I had a substantial air leak.

My air system has three air systems--the brake system, supply system and 12V system.  The brake system holds constant pressure and is monitored on the dash gauge.  The supply system & 12V system are joined together when the air pressure is above 60 psi.  Once the supply air system drops below 60 psi a 60 psi check valve closes and the 12V air system is isolated from the main supply air system.  REMEMBER:  NO TWO NEWELLS ARE EXACTLY THE SAME, SO YOURS MAY BE SLIGHTLY DIFFERENT.  The concept and methods of how to find air leaks though is the same.  Several years ago I made schematics of my supply air system.

If you have a 12V air pump and a 110V air pump it is much easier to find air leaks than the newer Newells that have a 2 110V air pump system.  

To start my search for my air leak the first thing I did was to isolate the main supply system from the 12V air system.  I shut off both the 12V & 110V air pumps.  I then drained the air tank I have in basement compartment R-1 and the air tank I have in the front of the right drive tire.  I then installed a leakdown tester in the 3/8" air line that joins the supply system to the 12V air system.  I then aired up the supply air system by turning on both the 110V & 12V air pumps.  Once the 110V air pump shut off I closed the valve on the leakdown tester.  The gauge on the side of the main supply air system did not drop & the 110V air pump did not come on.  The gauge on the 12V supply system immediately dropped until the 12V air pump came on at 30 psi.  The 12V air pump was cycling between 60 psi & 30 psi every 4 minutes.  This info told me I had a substantial air leak in my 12V air system & my main supply system was airtight.  

I shut off both air pumps and drained both air tanks.  I then reviewed my schematic of the 12V air system that I posted in the Documentation section of the forum.  I had four air systems to evaluate for leaks--the slide seals,  pocket doors, rear toilet and front toilet.  I started by installing a leakdown tester in the 1/4" air line coming off the air tank in front of the right drive tire.  I turned on the 12V air pump.  Once the 12V air pump shut off I closed the valve on the tester which isolated the rear slide seal from the 12V air system.  Tester showed the rear slide seal was holding pressure while the 12V system side was dropping and the 12V air pump was continuing to cycle.  I now know the rear slide seal is air tight.  Drained air system.  I then installed a leakdown tester into the 3/8" air line that goes to both slide seals.  Both slide seals were holding air pressure, but the 12V air system continued to drop.  I now have eliminated both slide seals and their air lines.

Drained air system.  Installed the leakdown tester in the air line between the 12V air regulator and the rear Microphor toilet.  I turned on the 12V air pump and shut off the leakdown tester valve when the air pump shut off.  The rear toilet was holding pressure, but the regulator side was leaking and the pump continued to cycle.  Reattached toilet air line to the regulator.  I have now eliminated the rear toilet and all associated air lines as the source of my leak.

Drained air system.  Installed the leakdown tester in the air line between the 12V air regulator and the front Microphor toilet.  I turned on the 12V air pump and shut off the leakdown tester valve when the air pump shut off.  The front toilet WAS NOT holding pressure.  I now know I have an air leak in the front toilet system.  

I still have the pocket door system to test.  Don't assume that you only have one leak.  Drained air system and installed leakdown tester in pocket door air line.  I turned on the 12V air pump and shut off the leakdown tester valve when the air pump shut off.  The pocket door air system held air pressure.

Now to find the air leak in the front toilet system.  I know it is a substantial leak so my tool of choice is my ultrasonic leak detector.  I remove the toilet tank cover and quickly find that the red air line at the toilet air sequence valve is leaking.  I noticed that the air line itself appeared to have pressure against it due to the way it was routed.  Drained air system.  I removed the line, rerouted it and reconnected it.  The leaking line was solved.  That air line had been hooked up for a couple years without leaking.

The tools I used are described in the Tool section in the Fun Stuff part of forum.

Hope this helps.......................................

[Keith Jordan]

Thanks Steve

[Richard]

Great write up! It illustrates the value of understanding the system, applying logic to isolate specific sections of the system, and a methodical disciplined approach to narrowing down the suspects.

You have me thinking. The one constant in Newell ownership is chasing air leaks. Your logic in separating the three systems has me thinking about permanent installations of the isolation tool(s) in locations to separate main, from 120v, from 12v systems.

So when I win the lottery my must have list for the Newell build will specify all compression fittings and an air system manifold similar to the water manifold.

[rheavn]

"Newell build will specify all compression fittings and an air system manifold similar to the water manifold"

Those two suggested improvements are far more important to improving the Newell ownership experience than adding another bell & whistle.

[Georgeb]

I’ve been chasing an air leak. Think I’ve found it…when air ram that opens Gen compartment is closed
I have an air leak…when open no leak. Any helpful hints on removing the cylinder ??????

[Aragona1]

I soaped every air line I could find. The toilet supply line was the worst you could hear it. Also found small leaks at the air bag supply line for the generator and the air dryer in the engine compartment. Compressor still runs about every 30 mins. Can the air bags leak too? How do you check them?

[Richard]

Yes the air bags can leak, however, for an air bag leak to effect how often the compressor runs, one of two conditions are necessary. The first is the coach is in autolevel mode which will activate the compressor to relevel the coach. The second condition is one of the six pack valves could be leaking. Remember the six pack isolates the air system from the air bags unless the travel solenoids are activated by key on, or the leveling system is active.