I've had my Yong Heng for a couple months now maybe 2-3 hours of run time. After filling my RAW 480cc tank maybe a dozen times the cotton filter has enough oil in it that I can squeeze some out of it. When I open the oil water separator bleed valve pretty much straight oil squirts out of it. Bleeding the line after filling my gun it smells like oil. That seems a bit excessive to me. Any ideas what's causing it. My oil level in the crank case is in the sight glass where it says it should be.
Yong Heng Putting Out Oily Air
- Thread starter Zach
- Start date
I have never had much more than just a tiny circle of oil on the compressor side of the cotton filter in the black holder that came with the compressor. Zero oil downline from that. Some suggestions blow to help diagnose the cause.
Make sure that the crankcase is level. On mine, the bottom plate that has the feet on it is not square to the crankcase so I put a small bubble level on the pump itself rather than on the straight line of the bottom metal to make sure it is level when filling with oil, checking the level and when running it. I had to put a piece of masonite under the front legs to get it level so the reading was true.
A photo of where the oil is in the sight gauge would be helpful to show where you have it. Too much oil can cause problems as I recall as of course can too little.
Also state what type of oil you are using.
Hopefully with that info, someone here will likely have some suggestions.
Make sure that the crankcase is level. On mine, the bottom plate that has the feet on it is not square to the crankcase so I put a small bubble level on the pump itself rather than on the straight line of the bottom metal to make sure it is level when filling with oil, checking the level and when running it. I had to put a piece of masonite under the front legs to get it level so the reading was true.
A photo of where the oil is in the sight gauge would be helpful to show where you have it. Too much oil can cause problems as I recall as of course can too little.
Also state what type of oil you are using.
Hopefully with that info, someone here will likely have some suggestions.
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Here are some pictures. Close as I can tell the oil level is where it shows it should be.
You replaced the oil fill hole screw-in cap with the taller oil breather cap? If so, oil breather cap should have hole open to atmosphere near top, check it out. WM
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I did put in the breather but didn't think of checking it but I just double checked it. It's open to the atmosphere. Thanks
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Zach,
There's another oil breather hole, at center bottom, might be restricted, if air exits oil breather top hole while compressor running, oil breather functioning. Oil level looks good, would consider piston ring problem, cracked case or if compressor was on its side, while filled, allowing oil to enter areas not designed. Think, in your shoes, I'd use compressor, keeping close tabs on oil level, while searching for additional clues, such as excessive oil use or unusual sounds. Best of Luck, WM
There's another oil breather hole, at center bottom, might be restricted, if air exits oil breather top hole while compressor running, oil breather functioning. Oil level looks good, would consider piston ring problem, cracked case or if compressor was on its side, while filled, allowing oil to enter areas not designed. Think, in your shoes, I'd use compressor, keeping close tabs on oil level, while searching for additional clues, such as excessive oil use or unusual sounds. Best of Luck, WM
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I change the white cotton filter after every fill of my 45 minute SCBA tank. If filling a gun, I guess I would do it after every 3 or 4 gun fills. A bag of 100 was pretty inexpensive on Alliexpress.
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I’m not worried about having to change the filter a lot I’m just concerned about what’s wrong inside. So far all the easy stuff checks out. I’m leaning towards a ring problem but I’m just guessing
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My yong heng slobers oil too. I've rebuilt mine several times. . Oil comes out when I purge it.. My big gold cotton filter is oily too. No moisture.... I think it the nature of them....hence not breathing quality air..... They work for $250.00 but not magic for sure.
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I would not want that in my airgun and you can be 100% certain you are contaminating your rifle. I would have some concern about flash point(and would research the MDS ... ) but even more so the crub build up that will cause your fine airgun to require maintenance.
3x times as much money as the lowest cost compressor but another reason I went with a Booster and oilless hotdog compressor .
That much oil, change that little filter every use.
And keep us posted if you figure something out.
John
3x times as much money as the lowest cost compressor but another reason I went with a Booster and oilless hotdog compressor .
That much oil, change that little filter every use.
And keep us posted if you figure something out.
John
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Question regarding the oil cap/breather. When you get a new Yong Heng, you have to replace a tempory cap for the oil reservoir. That temporary cap has an o-ring. The permanent cap/breather does not. Do you move that oring over from the temporary cap to the breather cap when setting up? That's what I did. Mine put out very oily air as well.
I no longer use a Yong Heng, but I'm gifting it to my Father-In-Law to get him started and want to be sure I'm setting it up correctly.
I no longer use a Yong Heng, but I'm gifting it to my Father-In-Law to get him started and want to be sure I'm setting it up correctly.
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Never had an issue with oil in my Yong Heng. Just a little bit on the cotton filter after many uses. Never seen oil blow out of the stage vents when purging. Just a little moisture.
Sound to me like an internal issue in the compressor, or like others mentioned, plugged vent on crankcase.
Hope you get it figured out.
Sound to me like an internal issue in the compressor, or like others mentioned, plugged vent on crankcase.
Hope you get it figured out.
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At this point I’m not getting any oil through my big gold filter. I’m keeping a close eye on that.
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M
Member 32425
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Hey Guys, I'm not intending to hyjack this thread, but I gotta ask Geezerhood a question here. Please don't flame me. I don't know how else to ask.
Hi Geezerhood. I once started a thread asking "are you sure your yong heng has enough oil", or something like that. I had a gut feeling that the oil level should be centered on the red dot when the piston was plumb (meaning the crank shaft was level) rather than just setting the compressor on a level surface as the instructions said. Again, it's just a gut feeling I still have, but I can't prove or disprove the validity of it. The crankshaft is definitely not level on any yong heng when the entire unit is placed on a level surface. Perhaps it is intentional and the sheet metal guys at yong heng were instructed by the guys that designed the motor, crankshaft, and piston to offset the crankshaft by x number of degrees. OR the sheet metal department just jacked up the back of the motor in the case so they could more easily install the power cord. It's all creepy gut feeling for me. Anyway, I still do what I think you are doing by placing a small digitital level against the back of the piston to make it plumb and then place stuff under the front legs to keep it there. THEN I check the oil or fill the oil. It seems to work OK unless I fill to the TOP of the red dot. At that point I think there is a bit of foaming going on. But if I only fill the oil to the center of the dot things seem to go OK. I only have 9+ hours on my yong heng with no problems, so not a lot of use.
When I started that thread a long time ago I kinda got a little flamed and ended up apologizing for starting an "alarmist" thread. And rightly so since I couldn't prove anything and I still can't. So now I'm wondering how you feel about this? Are there other folks following this "method" or "proceedure" or whatever I should call it. Did you read a post somewhere that influenced your decision to use the "level crankcase" approach?
Oh man, I know I'm gonna get the thumbs down again and won't be able to sleep tonight. Hope I don't get you in trouble as well.
grungy
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I should have added that my folding table that holds my Yong Heng has a visible slant on the top so I knew I had to compensate for it, otherwise the oil level would have been way off. It might well have been better to level it off the straight sides of the bottom metal. I will have to see how everything lines up on a level surface, though I am not too keen on moving the compressor since it is hooked up to the water bucket.
For those who have torn into one, how far away from the sight gauge is the little pickup probe on the connecting rod?
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