Yong heng compressor not filling

[Dcm2010]

I have a compressor and before I changed my oil it used to fill my pcp all the way up to 4500 psi and after I made the oil change it takes forever to fill and it fills only to 4000 psi if I’m lucky

 

[bigHUN]

That white thingy with a thread on one end only I removed from inside and zip tie it to outside... and more room now for internal cooling as well.

What about burning the second stage "plastic" piston rings .... don't let the oil get up there.
Along my years with YH I have learned that sometimes not worth loosing time troubleshooting... just replace the entire piston assembly... usually I am replacing about ones a year ?! speculating only that could be maybe about 10 hrs life on piston rings...
I have currently four spare pistons and three cylinders in my crate, from time these were dirt cheap have no idea what is ticket price today.
Also I would suggest replacing the old valves with new design, lasts much longer

 

[Grady1969]

I had to replace an O-ring on the plate where the reed valve is in mine once. Tank fills to 300 bar are still possible with mine but instead of taking 25 minutes like they used to the last one was more like 45 minutes and I still didn't get to 350 bar but got over 4000. The gauge failed months ago but I didn't use it when refilling my 45 minute bottle because I trust the gauge on the fill set a lot more. But I ordered one yesterday so I can dead head test it and look for leaks.

Another leak site I've had before that I did not notice mentioned is filters. I have two, the stock one and another with dessicant and both have leaked before. But usually those leaks are loud and obvious caused by O-rings.

I will start the YH with the dead head and only the stock filter on it, shut it off when I get to 300 bar, and listen for leaks. I will need to turn off the fans on the radiators and motor too but it should not be hot at that point. If I can hear hissing I like to move my fingers to the site and if I really have the site the noise changes. If I cannot hear anything but the pressure is decreasing I will look for my little leak test bottle. You can buy a small bottle of what is essentially red tinted soapy water at the hardware store. They sell it for testing gas connections which is what I bought it for but it works well for compressors too. I've had the steel lines on the YH leak too. Hopefully my slow down is a leak and not something more serious. It's four years old now. I've used NuvAir oil in it from day one but they still don't seem to last forever.

I put the dead head fitting in the fill line and started the compressor. Shut it down at 4000 psi and started soaping up everything that could possibly leak. The gage fell steadily as I preformed

That white thingy with a thread on one end only I removed from inside and zip tie it to outside... and more room now for internal cooling as well.

View attachment 570056

What about burning the second stage "plastic" piston rings .... don't let the oil get up there.
Along my years with YH I have learned that sometimes not worth loosing time troubleshooting... just replace the entire piston assembly... usually I am replacing about ones a year ?! speculating only that could be maybe about 10 hrs life on piston rings...
I have currently four spare pistons and three cylinders in my crate, from time these were dirt cheap have no idea what is ticket price today.
Also I would suggest replacing the old valves with new design, lasts much longer

View attachment 570058

I appreciate the advice! Where did you get those check valve’s from? I found a store on eBay that still offers free shipping but those valves are not there. Everything else is from spare O-rings to piston rods but no valve like those in the picture.

 

[bigHUN]

... Where did you get those ....

I am shopping on aliexpress much ahead of time, usually I buy spare parts at my convenience.
I am not focusing on YH store, I know they a bit more expensive, I buy usually where is cheaper and also shipping included.
The valve parts just an example, here:

https://www.aliexpress.com/item/1005003464594035.html?spm=a2g0o.order_list.order_list_main.47.3d671802wCGxNl

 

[Sleestak]

My YH stopped filling when the manometer failed....which was easy enough to figure out.

It also stopped filling at 200 bar when the crankcase developed a hairline crack. It was running fine and was barely noticable.

It doesn't take much for these things to not work properly FS. It doesn't help either that they are so loud when you're sleuthing

 

[Grady1969]

I am shopping on aliexpress much ahead of time, usually I buy spare parts at my convenience.
I am not focusing on YH store, I know they a bit more expensive, I buy usually where is cheaper and also shipping included.
The valve parts just an example, here:

https://www.aliexpress.com/item/1005003464594035.html?spm=a2g0o.order_list.order_list_main.47.3d671802wCGxNl

Thanks!
I‘m on Aliexpress a lot! Not that I can buy anything right now, but window shopping is free.

 

[Grady1969]

My YH stopped filling when the manometer failed....which was easy enough to figure out.

It also stopped filling at 200 bar when the crankcase developed a hairline crack. It was running fine and was barely noticable.

It doesn't take much for these things to not work properly FS. It doesn't help either that they are so loud when you're sleuthing

I’ve already upgraded the reset switch , it runs without shutting itself off now.
I‘ve wondered if that gage is bad.
Do you get a bunch of air coming out of the oil breather tube?
Mine will build pressure when I held my fingers over those two holes. Only for a few seconds but I can hear the air escape when I take my fingers off.

 

[Grady1969]

Customer service is tired of hearing from me. They offered me twenty bucks as a refund and suggested I find parts locally or a technician locally.
I have VEVOR’s phone number in California. I’m calling them today.