Air Compressor Maintainance

[Mike OMelia]

I have a Kobalt 60 gallon, 3 HP compressor. Its over a year old, maybe 2 years old. I bought it off CL. How often should I change the oil?

I thought I heard motor speed variation. It appears to be related to the belt. The bottom of the belt is vibrating a LOT. It does not look right to me. Does the belt need tightening? Should I replace it with a link belt?

Mike

[Josiah Bartlett]

Change the oil once a year. The oil doesn't really wear out, per se, but it does tend to pick up water in the crankcase after a while which can lead to corrosion.

The belt probably should just be replaced. It should be just tight enough not to slip. If it is too tight it will shorten the life of the bearings by quite a bit, and it won't make it vibrate less. I wouldn't bother with a link belt, just a good quality V belt will do. You aren't going to make it vibration free anyway, a 2 cylinder compressor has a lot of inherent imbalance.

[Steve Clardy]

Every 1-2 years if I can remember to do it. :o

[Mike OMelia]

OK. So what is that unsteady sound I am hearing? Is it the belt?

Mike

[Dave Lehnert]

I have a compressor I do not use much. I did not realize how loud that thing ran till I changed the oil. Made a big difference.
I would first change the oil then see if you still have the noise.

[Mike OMelia]

OK, will stop at Lowes and get some oil.

Mike

[Mr. Jeff Smith]

OK, will stop at Lowes and get some oil.

Mike

I bought some "Compressor Oil" at HD and swapped that in on a used unit I bought, seems to have worked fine. However, with talking with my father, he suggested having just used extra 5w-30 car engine oil I had laying around.

Well, I tried that this year and it actually made the compressor quieter and it is cooler to the touch too. Not recommending it per say, but it an alternate approach if you want to do it on the cheap.

Anyone else have experience with using engine oil? Clearly a compressor pump is very basic, I'm not worried about protection really, just curious as to why "compressor oil" exists.

[Gary Radice]

I think compressors require non-detergent oil, so if you use motor oil make sure you get it detergent-free.

I'm sure someone will correct if I'm wrong!

[Gary McNair]

Hi Mike
I just went through the same issue - motor speeding up and down - drove me nuts, I was sure the motor was going south. I removed the belt guard and found the belt loose. The way they build these compressor platforms - dead flat, it takes a lot of tightening to keep the motor from moving. It's a struggle to get the belt tight whilst maintaining the proper alignment - get a friend to help if possible.
Re compressor oil - use a non-detergent as these little pumps are self lubricating- the splashing crankshaft creates foam in a typical detergent oil. I change my oil every 18 months - I don't believe this is critical tho - my compressor is 15 yrs old.

[Bill White]

Bought my primary compressor in 1978. Change oil whenever I remember (at least every 3 yrs.). Keep the tank blown down. Varied speed?? Is the power surging? 120v. or 240v.?
Bill

[Mike OMelia]

Hi Mike
I just went through the same issue - motor speeding up and down - drove me nuts, I was sure the motor was going south. I removed the belt guard and found the belt loose. The way they build these compressor platforms - dead flat, it takes a lot of tightening to keep the motor from moving. It's a struggle to get the belt tight whilst maintaining the proper alignment - get a friend to help if possible.
Re compressor oil - use a non-detergent as these little pumps are self lubricating- the splashing crankshaft creates foam in a typical detergent oil. I change my oil every 18 months - I don't believe this is critical tho - my compressor is 15 yrs old.

I changed the oil with non-detergent stuff from Lowes. Good thing too. The old stuff was nasty looking. I think the real issue is the belt tension.

Thanks,

Mike

[Glen Butler]

Mine recommends every 100 hours.

[Mike OMelia]

Seems to be doing better now. For reference, it took 2 16 oz bottles to refill. BTW, that stuff is high viscosity oil. Before I drained the oil, I pressurized to 50 psi. Then, after removing the drain, I wrapped a blower valve with a paper towel, inserted it into the fill hole, and blew the oil out. Yes, I had a dessicant dryer on the other end. Otherwise, it would have taken hours to get it all out.

Mike