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View Full Version : Air Compressor Oil Quandry- 10W-40 oil?



DS_park
04-15-2018, 01:52 AM
The service manual I have for a 1973 vintage Craftsman air compressor head (Campbell Hausfeld) says to use 10W-40 detergent motor oil. All I have ever heard of using is non detergent oil. The compressor came from an estate sale so I don't know the history of oil changes. Leaning towards the 20 non detergent oil I have on hand. Any thoughts or recommendations?

ironmonger
04-15-2018, 07:27 AM
I have a Campbell Hausfeld compressor (JC Penney branded) 220 Volt compressor dating from the late 70's. I have used 20 strait weight and 10-W40 over the years. I have abused it by changing the oil every New Years day since 1978 using pretty much what ever oil I had to hand. I guess it's better to have any fresh new oil rather than old correct oil. If it was going to die from incorrect oil I guess it would have happened by now. Original belt as well... so having mentioned that I guess I should pick up a spare belt :>)

It is admittedly in light duty service, but it has been 40 years... It lives in my basement breathing air conditioned air and feeds a 30 gallon receiver in the attached shop/garage.

If it packs it in tomorrow it's replacement will get the same service.... but I prolly won't be around in 40 more years to change the oil every year...

kev74
04-15-2018, 09:59 AM
I'd do what the manual says, especially since the recommended oil is readily available.

RMinMN
04-15-2018, 10:12 AM
5W40 synthetic. The compressor will start easily in the cold but have the thicker lubrication it needs when it gets hot. Works good in engines of that vintage too.

vpt
04-15-2018, 10:59 AM
I haven't changed the oil in my compressor since I got it. It is on and full 24/7/365 and gets used daily.

I did check the level this year and it was right where it always has been and clean. Though I guess compressor oil doesn't get dirty like a vehicle because no carbon.

I do need to change it one of these years.

garyhlucas
04-15-2018, 12:15 PM
I had a customer using an air compressor to supply misters in a greenhouse running 24/7 and he was replacing the compressor once a season. I suggested he make the oil change interval like his car since they both draw in air. Changing the oil once a week during the season in that service got him quite a few years on the compressor.

BCRider
04-15-2018, 01:01 PM
I haven't changed the oil in my compressor since I got it. It is on and full 24/7/365 and gets used daily.

I did check the level this year and it was right where it always has been and clean. Though I guess compressor oil doesn't get dirty like a vehicle because no carbon.

I do need to change it one of these years.

Back when the SAE ratings on motor oils changed from G to higher letters there was a lot of hullabaloo about oil in the motorcycle magazines because the new additives that produced the upgrade beyond "G" caused the wet clutches in motorcycles to start slipping.

In these articles some of the testing was done to measure the long chain modifiers and how the lubricity of the oil might degrade in use due to pressure issues and not only the ability to hold combustion byproducts in suspension. This matters to us bikers because the transmissions on a lot of bikes uses the engine oil for lubrication.

Seems that over time these long chain molecules can be ripped apart and the oil loses lubricity. Even if it's not dirty. Now an engine or compressor is nowhere near the torture chamber that a transmission and wet clutch is but even an engine or compressor will eventually break down the long chain molecules. And obviously a compressor won't turn the oil black due to the lack of byproducts...... or, if it does then the air it is breathing is very dusty or there is solid metal to metal wear in the oil......

This breakdown was measurable with a check of the viscosity. The viscosity or oil "thickness" rating number being lowered by the damage done.

But that aside I would suggest that for a compressor that is in use 24/7/365 and runs at least twice a day to keep the tank charged that a year is more than enough to expect from the compressor oil. The fact that our compressor oil stays clean may be masking how "worn out" it really is in terms of a lowering of the viscosity number over time. It's quite possible that it's still fine even after two years. But three or more?

On the other hand compressors that sit empty much of the time and only see use once or twice a month and don't live in conditions where humidity and the risk of internal condensation could well go for a decade just on the same oil.

RWO
04-15-2018, 01:06 PM
Why not this? https://www.amazon.com/air-compressor-oil/s?ie=UTF8&page=1&rh=i%3Aaps%2Ck%3Aair%20compressor%20oil

RWO