Compressor oil breather blew clean off.

[ImpactX]

Had my hatsan lighting for a month now. Only used it maybe 5 times and had 4 hours on it. All is good until today. I turn it on no more and 2 second and I heard a pop and something flew from the compressor. I look on the floor and found the oil breather. I was sure I screw in on, how can it flew off. So I look at it and the thread broke clean off. How did the crank case even build enough pressure to blow the breather clean off like that? Isn't the breather supposed to let air out so it doesn't build pressure inside the crank case? I've seen someone with a crank case blew off. Probably due to same issue. Glad the breather gave way and not the crank case. But damn. Any idea how this could of happen and how to avoid it in the future?

 

[Jammin22]

I would say the threads were cracked from over tightening the breather. And finally broke the breather off.

 

[marflow]

if you look at the threads they will tell the store of where they have been damaged and where the final break did occur

so did it really blow off or just fall off from the vibration at the time of the crack making it to weak to stay in place

with that said the new breather might need same extra support or a whole new breather of a different type

just guessing

 

[edosan]

That happens to me once in the yh compressor, due a broken piston...not saying is the reason but it might

 

[DirtyDovi]

Yup, either damaged plastic/threads, or, something like damaged piston or rings.. 
The crank case shouldn't have very much pressure in it at all..
If/when rings or a piston goes, the pressure from the head can 'blow by' down into the case, 
built up pressure, and create havoc - like possibly blowing off a breather/filter.. 

Hopefully it's the cheaper/simpler issue of the two..

 

Sam -

[Edit] Oops, I was a bit too quick on the draw and hit submit too soon..

IF there is any damage to the con-rod/piston/rings, you'll know it due to sound, rattle, 
or, the comp just won't be able to build up any significant pressure..

 

[socaloldman]

The plastic on those breathers is crap. Two of them broke on me. First one from over tightening (my fault) it just fell off in my hand and second one was just plain junky plastic lasted maybe three months before I noticed it wobbling and it fell off broken at the threads. Went to a metal replacement.

 

[bandg]

Seems many might like to know about that metal replacement.

 

[airgunfans]

Over tightening is the likely problem. I have once tried to tighten the one on my Yong Heng by tool and it broke with little resistance. Just use your hands. There is no need to be very tight here. 

 

[marflow]

does your owners manual have a parts diagram and does that diagram have the thread size if not I would just make one

I believe it could be a piece of tubing force threaded in the hole with a cap that has a hole in it

this kind of looks like what is being used but without the thread size I'm guessing

https://www.aliexpress.com/item/32538070280.html

 

[ImpactX]

Idk if it was due to over tighten or pressure in the crank case..all I know is it broke off. I didn't use any tool to install the breather. Only hand tighten. Was good for 4 hours run. Guess I'll have to order a new breather. Will try not to tighten it too much this time. Hope that helps.