My air compressor is leaking a lot of a oil from around the edges of the sight glass. How do I fix this?
Based on the shape, is it threaded on? Do I just need to tighten it, or maybe add some kind of thread sealer? It's hex but it's plastic so I don't just want to wrench on it and break it without knowing what I'm doing.
Air Compressor Oil Leak
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Air Compressor Oil Leak
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Re: Air Compressor Oil Leak
I assume it's a Campbell Hausfeld brand. Have you checked to see if a replacement sight glass is available?
David
David
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Re: Air Compressor Oil Leak
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Re: Air Compressor Oil Leak
Tightening it will likely do nothing but break it, if it will even tighten any further.
I have had a few compressors over the years and have seen some that are sealed with an o-ring and some sealed with a pipe sealing compound.
I am sure you can carefully unscrew it and see what is used to seal yours and should be an easy fix.
BTW if I ever need orings I go to Amazon and you can get a kit with all different sizes pretty cheap and super handy to have in stock.
I have had a few compressors over the years and have seen some that are sealed with an o-ring and some sealed with a pipe sealing compound.
I am sure you can carefully unscrew it and see what is used to seal yours and should be an easy fix.
BTW if I ever need orings I go to Amazon and you can get a kit with all different sizes pretty cheap and super handy to have in stock.
DIY 2x2 table
Everlast 82i
Everlast 82i
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Re: Air Compressor Oil Leak
Nobody has mentioned a breather possibly being dirty or plugged. They are normally mounted on top of the crankcase below the jugs. Be sure to clean and inspect it.
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Re: Air Compressor Oil Leak
Lots of great ideas here! Let us know how you resolve your problem.
David
David
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Re: Air Compressor Oil Leak
Interesting story, my buddy's compress had a clogged breather and just as it would complete a cycle the case had enough pressure built up to blow the breather out. 

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Re: Air Compressor Oil Leak
That's a good call and a good thing to check firstSegoMan DeSigns wrote: Wed Jun 11, 2025 12:50 am Nobody has mentioned a breather possibly being dirty or plugged. They are normally mounted on top of the crankcase below the jugs. Be sure to clean and inspect it.

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