Air Compressor for an Cummins ISX question

Mine does the same thing but took off intake air line and air comes out what can it be

 

you are getting water in the tanks sign of a bad air dyer buy a new filter for it and change it make sure all the inside is clean from carbon as well you can buy kits for these
AIR DRYER is your problem

also check the main steel line that goes from the compressor to the air dyer make sure this is not blocked
on the air dryer there is a small airline which goes back up to the compressor that turns the compressor on and off it screws in on the back of the compressor (non mounting side) try disconnecting that line and start the truck and make sure the air dryer doesn't blow constant air as to disconnecting this line it makes the compressor run all the time

try spraying a little CRC in the intake for the compressor while running

 

I has mysterious leak for over an year could’t find it. Few days ago i got tired of it and decided to pressure test the system. I couldn’t build more then 9psi in the system and the pressure was dropping dramatically. The worst thing is that it was on the other side of the engine on the cold side. I had friend pressurizing the system while me locating the air leak. What is found was air compressor head had massive air leak on the back of the head, most likely blown gasket. Will replace it this upcoming friday. Some leaks are so hard to find especially with the engine running almost impossible to hear where is coming from. Hopefully this will help to someone in the future