Though all oil-lubricated compressors from different compressor manufacturers may have slightly different oil change processes the overall concepts presented on these pages will work for all oil-lubricated compressors.
Some of the questions you will want to have answers to before you open the compressor oil sump are covered on this first page.
Not all compressors are oil lubricated. In fact, a lot of the little DIY type air compressors now available from the big box stores are added-lubrication oil-free. they are factory lubed for life, so you cannot change the compressor oil in these compressors because there isn't any to change.
Lubricating oil that is added to the compressor flows down into the oil sump and sits there, under the pump, waiting for the compressor to start.
The typical DIY type oil-lubricated home compressor will be the splash lubed variety. If it is splash lubed there will be no extraneous oil pump on the compressor, meaning there is none to maintain or replace. If your compressor is designed to be splash lubed, that process works just fine.
My rule about what compressor oil to use is simple. If my air compressor is under warranty, I use the oil that is recommended by the manufacturer and usually noted in the compressor manual. If the warranty period for the air compressor has passed, then I buy compressor lubricating oil from my hardware store to use in my compressors.
For me, this rule applies my home DIY compressors only. Some of the more sophisticated and larger compressors - rotary screw, vane etc. - used by industry have very specific requirements for oil. You must use the oil recommended by that compressor manufacturer or you void the warranty or cause oil-related issues.
Compressor oil has the proper additives to make it suitable for the harsh, compressor lubricating environment. These additives are not necessarily found in automobile oil, air tool oil, etc.
The additives that are other types of oils are not compatible, and in fact may damage, your air compressor. If it does not say compressor lubricating oil on the package, don't put it in your compressor.
For the DIY type air compressor user, unless you are using it all the time, follow the manual guidelines or change the oil once a year.
If it is an industrial air compressor being used continuously, depending on the model of your air compressor and the manufacturer's recommendations, consider changing the oil every 300 hours of compressor operation.
Let's get down to the process of actually changing your compressor oil on this page.