# Vacuum Pump Smoking!!



## Kendallqn (Jul 3, 2014)

Ok So I went out and bought a vacuum pump.  I think a good one.  A Robinair 5cfm 2 stage.  The problem is I ran it tonight for the first time and it smoked and spit oil the whole time it was running.  The whole shop filled up with a haze of smoke.  And I couldn't quit because I had chucked up a platter I was finishing the bottom up on.  My question is, is this normal?  Is there something I need to check?  My old system is a venturi valve set up that is loud and has the compressor running all the time.  Thought this would be better after reading all the comments from folks here that use them for casting and all.  Any help would be appreciated???


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## Jim Burr (Jul 3, 2014)

In my experiance, it is. Head over to your local auto parts place and pick up an oil filter that's about the same threaded opening size as the exhaust on your pump. A little trial and error on your part to find the right size, but it worked for myself and many others...but still JMHO.


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## randyrls (Jul 3, 2014)

The "smoke" is an oil mist.  You may have overfilled the oil reservoir.   To add to what Jim said, you can get filters like this from several sources.


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## MesquiteMan (Jul 3, 2014)

The reason your pump is misting is because there is a lot of air moving through the pump. When vacuum chucking, you are overcoming air leakage. All that air is passing through the pump causing the mist. Oil filled rotary vane pumps are best with very intel air passing through them such as stabilizing where you are not dealing with air leaks and free air (if your chamber is built properly).  You can do as Jim said and rig up an oil filter or just let it be. Vacuum pump oil is simply highly refined mineral oil so the oil mist is not hazardous at all, just annoying 

One other thing about spitting oil...make sure you always start and stop your pump with no vacuum on it.  In other words, always release vacuum and allow the vanes to clear (change in sound, about 3-5 seconds) before shutting off the pump. If not, it will cause wear on the pump and make it spit oil on the next start up.


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## Kendallqn (Jul 3, 2014)

Thanks For the help guys.  Ill go get an oil filter then and try that.  Hope everything is ok with your wife Curtis.


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## terry q (Jul 3, 2014)

I have the same problem while stabilizing blanks.  I put a plastic tube on the outlet side and run it out the window.


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