Guess title says it all . This old truck had been sitting for few months but previous owner was using it some . Don’t think he ever drained the petcock on bottom of tank just one they rigged up on front side which is mid way . So I keep draining and draining and keep getting back oily moisture . I’m thinking about removing or replacing tanks . But do y’all think something is wrong with compressor ?
Now, yes, your compressor could be going or it may just need to be run more.
I would suggest you first drive it and then drive it some more and then see if you still get any residue other than water when you drain the tanks before you start swapping parts out, etc. Get everything good and hot regularly and make sure you are using air and forcing the compressor to cycle. It sounds like your compressor may be running OK but just needs to be run to get things to seal back up. Or maybe there is just some old sludge in the bottom of the tanks that is purging little by little each time you drain them and it is nothing actually "new".
I had a similar experience when I first recovered my Deuce. It had sat for several years without being run. For the first couple of months I was idling her a lot and just making short maintenance runs close to the farm as I was working through various problems. During that time I was getting a lot of black residue out of the wet tank as well.
However, once I got to the point I felt comfortable I had addressed all her major items and I started regularly taking 1+ hour drives and long trips into town with her it cleared up and I have never had a problem since with any non-water residue when I drain the tanks at the end of the day, even if she sits for 2-3 weeks without running. Lots of other minor annoyances disappeared as well once I put some good miles on her.
I also found the same thing with my 5-ton...the more she gets driven and treated like a truck the better and better she runs and some issues fix themselves.
If the truck is building and maintaining air and the brakes are solid and safe...drive it and see what happens.
