Well, Dana at Poseidon compressors in Vermont is still answering the phone on occasion, so you could try to ask him. But as a fellow Poseidon compressor owner, here’s what I can tell you:
When I bought mine, it came with a container of “Poseidon 751”, with the Poseidon Vermont company address and everything on it. You can be certain that a guy in the far northeast is not producing his own lubricants… And I think the 751 tells you all that you need to know: these compressors came from the distributor using UltraChem ChemLube 751.
Assuming they continued to use synthetic oil during their life, that’s what you want to use in them. However, if they were switched to mineral oil, they will be full of carbon deposits. If you stick with mineral oil, those carbon deposits will stay where they are. But if you switch to synthetic now, the highly aggressive synthetic oil will merrily liberate those carbon deposits, leaving them in your valves, in the cooling tubes and every place else that you don’t want them. Don’t do that.
There is a procedure for switching from mineral to synthetic oil, but it can basically best be described as “tear everything apart, clean it really well, put it all back together, and change your oil several times over the next 20 hours of running your compressor“. Not a procedure you undertake lightly.
Also to give you a heads up: these are compressor blocks built by Bauer Austria. They share a great deal of parts in common with old Bauer compressors, but they are not exactly the same. for example, my guess is the big one you have is a PFU – 150. That is a six CFM compressor very similar to a Capitano, but it is splash lubricated instead of pressurized. Believe it or not, if you email Bauer Austria with the serial number they can actually send you the service manual/blueprints for that compressor. The part numbers are slightly different, but close enough that you can easily identify the proper Capitano parts for that compressor.
One thing to note: if it has the silver square auto drains with the big round wheels, that’s an oddball that is hard to get parts for. Don’t mess with it if you can help it.
I have now given you most of my knowledge about Poseidon compressors, but as a fellow owner of one, there might be other little details I might be able to fill-in. Feel free to DM me if you have further questions.
) of Poseidon compressors recently. One 3600 PSI and the other a 4500 PSI unit.
