2nd air gauge not working

[Waterloo]

I would try the WD-40 and then if that does not work, get the head kit for the compressor, if that is the direction you believe you should go. From everything I have been told, it is the head that fails on these compressors, not the compressor itself. This has come direct from my local Cummins shop and more than a few of their mechanics when I thought I was having issues with mine. I have also heard the same from other shops, fleet shops, that work extensivley with the ISX motor.