If the the pressure is much more than normal check the wear and ovality of the cylinders and replace them if required.
It is best to hone or deglaze old liners when fitting new piston rings to compressors, just as it is with engines.
Check the wear and ovality of the piston and the clearances between the pistons and the rings, the piston may need replacing.
Check the piston rings are installed correctly, some piston rings must be installed one way up.
There should be a crankcase "breather" designed to allow air to flow in and out of the crankcase, without oil loss, as the piston reciprocates, check that this is not blocked.
That is all I can think of for now.
It is always better to ask a stupid question than to do a stupid thing.