Yong Heng air leak

Most leaks are easy fixes just o-rings or dowty seals. Check to see that the gauge is tight. Do not over tighten it or you can ruin the seal. Check the burst disk for tightness or a leak coming out of the hole in it replace it if needed. The dowty seal on the stainless line on mine blew out once so that is another place to check. If you got your unit new you will have all the replacement parts to repair these leaks as they are included in the kit that comes with the compressor.

The Stainless lines can be tight and difficult to get apart. Put two wrenches on and bring them close enough together to grab with your hands and squeeze. Hands are really strong.
 
I've taken lapping compound to mine where the stainless lines seal. Just put a tiny smidge on the seal it's self, take the line and twist it so that the seal rubs on the seat (sealing surface) a bit. Then clean the lapping compound off. A couple of mine wanted to leak after disassembly. Never have had another issue with several teardowns. 


 
So I got the stainless line off and put rubbing compound on nothing ends. Hooked it all back together and there is only a tiny air leak now. It doesn’t hesitate at 2800 like before. I think I can live with it now. Thanks for the advice!


Just checking, Hummer57

No insult intended

You did clean off the rubbing compound before joining the fittings together, correct?

You do not want that abrasive, as mild as it is, to get into your tank or rifle.

Ed
 
 

Hi Biohazardman,

I apologize for interrupting this thread, but after reading your advice to HUMMER57 ( about solving his Yong Heng leak) I had to inject myself, because I'm currently having a similar problem. I got this feeling you have the Yong Heng experience and knowledge I'm looking for.

specifically in the area (shown circled in red, in the picture below) where the tube nuts thread into the cylinder housing?

This is where my air leak is coming from----it's rushing from that area. 



Based on the picture I've attached, Do you know if those are two separate nuts and can they be taken off the tube?

I understand there is a ferrule sealing that tubing connection. If it's damaged or compromised (and causing my air to leak) I won't know until I can remove the nuts from the tubing and examine it. I presently have removed the tube with the nuts from the machine. The nuts are still attached to the tube.

I'm holding off doing anything else until I find out more about these nuts and stainless tube

My question is; am I able to use( 2 wrenches, one on each nut) and bring these nuts (separate/ apart ) off the stainless tube?

ALSO

I know the Yong Heng uses Dowty O-rings to seal this connection( I have extras) but do you know, or have you ever used, Thread sealant and/or Teflon tape to secure that specific connection (or any-other connection on your Yong Heng) from air leaks?

Thanks for your time reading this. Any advise will be greatly appreciated.

Best Regards

Jef Artist

Nyack, N.Y.



YONG HENG LEAK space between tube and nut2.1600051862.jpg

 
 

Hi Hummer57,

The "metal shaped washer" you're referring, the people at Orion Motors, who sold me the Yong Heng (through Amazon) (They've been assisting me, too) They called it a "Ferrule"

I have a question about how you separated the two nuts on that tube; Did you place a wrench on each and apply great force? I ask because it's really---a "tough nut"! (pun intended)

:)
 
Hi Hummer57

Just letting you know, I separated the nuts and was able to examine the threads and ferrules on that stainless tube.

I gave everything a cleaning then applied thread sealant and Teflon tape. The leaks are resolved.

Many thanks to you for the info you provided! 

My only remaining question to you (and others on this thread who are in the know) There is a black breathing plug/cap that screws into the port where the oil is poured. My issue is with the vent/breathing hole at the top of that plug/cap.

When the Yong Heng is operating (pumping) I feel air coming from that hole. It's not a lot of air but it sure feels like enough where it might be affecting (limiting) pressure output.

Let me know if you've experienced this. Any thoughts or concerns?

Important note: Even though I've felt air pumping out of this hole, I was still able to re-up my 3 liter tank from 200 BAR to 310 BAR in about 10 minutes.
 
Hey Ed,

Your comment is appreciated and not taken as snide.

The "Breathing" hole (as if to breath in and out) makes complete sense. 

The oil reservoir is a separate environment and the in and out breathing is isolated there. It does not affect the general PSI pressure produced by the cylinder.

If I'm wrong, please tell me.

Thanks!

Jef

Nyack, N.Y.