Compressor oil change interval

[Graeme Tolton]

I currently have a Davey 15 cfm compressor. I just switched to chemlube 501 from a mineral based oil. I plan to change the oil again after about 5 hours of run time.

All that being said, how often should i be changing the oil and filter? The sump holds around 4 liters and the filter holds nearly one more liter. That adds up to a very expensive oil change. If it needs to be done, it needs to be done, however i dont want to be changing it prematurely or over extending it.
Right now i have 316 hours on the compressor.

 

[Wookie]

I change mine every 250 hours. The expensive bit is that when switching from Mineral to Synthetic, you need to change it, run it for an hour or so, then change it again. Don't skip this! Be sure to change the filter too.

If you're not putting many hours on it, I'd change it twice a year anyway.

I'm getting my oil for about $25 US per US gallon. An oil change isn't that expensive...

 

[divingtactics]

The issue with changing from Mineral to synthetic is that all of the carbon build up from the intercooling tubes, separators, barrels, heads and valves will loosen and work its way into your filtration system in time. Bauer suggests that only within the first 100 hours can you change from mineral to synthetic oil. However, if you are prepared to pull the entire compressor down and clean all the things mentioned above, you can do the change as I have done on my system. I put everything in a large 5 litre (1.3 gallon) heated ultrasonic cleaner and did a dual wash at 80 degrees C (176F) with Simple Green and the second wash in Simple Green Crystal. Blew everything out and dry with scuba air and put it all back together. There have been no deposits in my filtration system and as a special measure, I also have a 30 micron particle filter after my primary filter too.

I change my synthetic oil every 50 hours or annually - whichever is first. Oil is cheap when compared to compressor repairs.

 

[Graeme Tolton]

Thanks for the input! My compressor has a pressure gauge for each stage. It also has a moisture trap and screen in between each stage.

It is also equipped with a very large oil filter, specifically the monster that ford used on their v8's for years.

However, with all that being said, i do monitor the stage pressures while it is running. I will also make it a habit to check the screens in between the stages regularly.

If i start to see a lot of carbon built up on the screens, i will have to do some major cleaning, but for now i will keep the oil fresh and monitor everything closely.