After a bunch of reading the only reference I can find to this is a bunch of people having the issue practical machinist but no solutions and most people just living with it and letting their compressors run more frequently!
The problem is that there is a constant flow of air coming out of I believe the front exhaust value of the power drawbar system that is on the left side of the tower. These are the exhaust valves you adjust for how aggressive the engagement and release of the PDB is. I made no changes to them. Just one day it started having a constant leak.
PDB still works fine. Just really annoying and over cycling my compressor.
Have you tried replacing the valve assembly? The PCNC’s are starting to get a little long in the tooth so I wouldn’t be surprised if an o-ring in that valve has failed. Some of them can be rebuilt, but replacements are readily available and usually pretty cheap depending on where you source it.
I have not. I wanted to see if anyone had concrete information before I go start messing around with things. Because if I do go do that, it will truly be like a caveman poking at it with a stick until it works Ha!
I’m finally getting around to having time to address this. Crawled in the enclosure to remove the part and take it apart to see if any seals were blown.
No need!
The adjustment part of both exhaust valves are gone. No idea where. No idea how long although my obvious assumption is about the time it started making the hissing noise. Let’s hope it’s as simple as ordering two new valves and replacing.