Weird yong Heng not filling past 2500psi

[Fasyankee]

So I’ve had the compressor for about a year. Only used it to fill/top off airguns never filled a large tank. Temps have never gone over 55c. Two things my gage won’t go below 1500psi when disconnected/off and now it won’t fill past 2500 psi. It’s not the auto shutoff version and I’ve always bled the high pressure first before shutting it off. I’m assuming there’s a leak. Any suggestions on where to start looking? I checked all the fitting and everything appears to be tight, it’s just tough to hear a leak with the compressor running!

 

[ImpactX]

Sounds like a broken gauge. There is no way you can disconnect the lines with 1500 psi still in it. It would whip the line. Very dangerous to try to disconnect anything with pressure. Bleed it off first. If it's still showing pressure then gauge is bad. To look for leak. Turn on compressor to build pressure and turn it off. Do not bleed it. Listen to leaking noise. 

 

[Butch]

A spray bottle of soapy water for the fittings work good for me. 

 

[airgunfans]

If it cannot go above 2500 psi, the leak should be big enough to be audible after the compressor is off. Find a quiet place. U should be able to hear it. 

 

[Fasyankee]

Where’s a good USA source for a gage? I can’t stand ordering stuff from China.....last time I did I waited 8 weeks for a bipod......

 

[biohazardman]

It's not likely you will find American gauges with metric threads. There are few places that have parts for the Yong Heng compressors.

https://www.aliexpress.com/wholesale?catId=0&initiative_id=AS_20191227201955&SearchText=yong+heng+compressor+parts

Mine blew out o-rings form the filter first. Then a Dowty seal from the top of the head after I overheated it. The parts I needed came with the compressor in a spare parts bag.

If you turn the compressor off without purging it you can probly find the leak fairly easy.

 

[Fasyankee]

So yeah, it’s the gauge. Put the test plug in the foster quick disconnect, let it build as much pressure as it would and shut the compressor off. Hissing out of the bottom of the gauge clearly. PA has a gauge from air Venturi that’s got the same threads but no wire for the auto-shutoff (4500psi only) and I never fill that high or leave the compressor unattended as I don’t fill bottles only the guns directly so I’ll just go with that one.

 

[Fasyankee]

Update: while I’m waiting for the gauge to arrive from pyramid air I had a little “lightbulb over my head” moment......I have a Hatsan 3 stage hand pump....it's got a gauge.....and guess what? It fits! I figure with the holiday the shipping isn’t going to be so quick so this will nix my downtime till the new gauge arrives.