I’m hoping you can help. I picked up a 1997 sullair diesel towable compressor at auction. It was not running when I got it. I finally got it running after a new injection pump. While it’s running it won’t produce any air. The tank has fluid. I even pull the pressure release on the side of the separator tank while it’s running and nothing. I’ve tried manually opening the intake valve and it didn’t change anything. I even thought there might be a problem with the hydraulic thermostat and bypassed that and that didn’t change anything. Is there anything else I can do/test before I tear into the pump? It seems like l the small air lines are hooked up properly. Also I’ve been running it at idle mostly. I did go full throttle with it a few times and still no air. Any help would be appreciated. Thanks
It sounds like the screw element is not running at all – the coupling is broken.
Some machines have a rubber coupling, others are belt-driven.
The easiest way to know for sure is to remove the inlet valve, and crank the engine, you should see the screw turning as well.
All the best,