Impossible to find air leak

Whatever you find out PLEASE keep us posted with the details.
Hope you find it.

 

I meant the actual gauge itself, not just the fittings on the back.

This one's a real head scratcher. How did you isolate the compressor? At the compressor or the wet tank? I've been told that the braided hose off the compressor can let air escape through the braids over its whole length as it gets up there in age.

 

With both tanks draining, I think that you would have either the primary or secondary check valve bad. There are very few things that could drain both. Did you block off the gladhands to be sure that the trailer valve is not bypassing, that has the 2 way check that could drain both tanks. Foot valve has both sides going to it, but should be separated. What else could drain both?

At this point I think I'd just change the check valves to be sure. It wont fix your leak, but if one is bad, it will at least hold air in 1 tank and eliminate one or the other so you can narrow your search to 1 side.

The only other thing I can think of that hasn't been mentioned is drive it into a lake and find where the bubbles are coming from.

 

This is extreme but I don't know as it will take more time than you have already spent. Remove every air line from every tank. Plug every port except one and put an air chuck in it. Charge each tank individually. Be sure that none of the plugs you put in each port is leaking. Check that the tank holds air. Then drain it, install one line, recharge and check for air loss. You could work back and forth between two tanks. While waiting to see if one loses air work on draining and installing a line in another tank and charging it. I would think that eventually you would install a line and that leads somewhere and won't hold air. Liquid dish washing detergent mixed with water will hang to whatever it is sprayed onto longer than windex. Or buy a commercial leak detection solution. I thought I heard of some real head scratchers but this looks like an all time record holder.

 

Just saw on the news.. big heat wave and lots of brush fires down under........

Be save down there Ozdriver.

 

Does your truck have the air operated windows ? I remember some of those ole 100s having those.

 

Hello,
Have you checked the base/pedestal of the air bags? I have been having a nightmare of a time chasing air leaks. Air was leaking at the quick connect that supplies the bags. that was found by shaking the lines. Air was also leaking at the bags but only found by changing two of them one at a time. Each time the leak lessened. It turned out the air was leaking at the base of the bags and only showed when submerged in a tyre tank.