Sanborn Air compressor model 89b200-14la water rel

1. The Water release valve, I tried a wrench and Tried to release the big nut on the empty area, seems like it was 5/8th's it was so tight it rounded the metal some BUT it seems that it has another threaded handle (small about 2 inches wide) which spins clock wise and moved UP tward/into the tank, when counter spun it moves DOWN, I assume that when it spins all the way up it should let any water in the tank to drain then the lower position is closed??

someone please let me know if yours is the same..

2nd question

it appears to be a 2 piston oil based (can see some soft or threaded plugs on the piston area, but not sure what the oil level should be, how to check or even what type of oil to use for that matter,

please help any information is aprecated!!

Thanks everyone

#2. My Sanborn (15 yrs old, Vertical 5HP) gets SAE 30 non detergent in summer, SAE 20 in winter, as it lives in non-heated barn outside shop area. My oil drain and fill port is a tee fitting at bottom of compressor, drains from lower plug, fill with upper plug to bottom of threads for plug.

Hope this helps, Bill C.