Tuning Zbroia Hortitsia has a slow leak

[RevonocAce]

Hello again, Airgun experts. 
My Zbroia Hortitsia seems to have a slow leak. Over the course of two days it went from 280 bar to 155 bar. I filled it up earlier to 285 bar to track its leak. 
A friend of mine is going to help me attempt to figure it out tomorrow, so I’d like to have some ideas as to what it is. Thanks for the help, as always!

The pictures below are 25 minutes apart. 

 

[nervoustrig]

The good news is that is a leak severe enough that it should be easy to find. Possibly even audibly in a nice quiet room. Try opening the bolt and putting your ear up to the loading port and listen into the barrel. If the poppet is leaking, you will hear a hissing similar to putting a seashell up to your ear.

 

[RevonocAce]

Thanks for the quick reply. I’ll try that here shortly. It’s down to 255 bar now.

you really think it’s substantial enough to hear?

 

[jdh2550]

Following, my Kozak has a slow leak. I wish you luck and a quick solution. 

 

[nervoustrig]

you really think it’s substantial enough to hear?

If it is the poppet, most definitely. Just a couple of days ago I had a new rifle losing ~300psi in 6 hours...much slower than your rifle. I could hear it plainly with my ear up to the loading port. It's harder to hear a fast leak in other areas for sure but running a finger over suspect areas will sometimes produce a turbulent sound that you can hear. I mean it's an optimistic outcome for sure but worth a try for a leak like yours of something like 450psi per hour.

 

[RevonocAce]

Ok, I checked it again this morning. Down to 165 bar. I tried every way possible to hear sounds, but couldn’t find any. 
I guess I have to learn how to take this bad girl apart. 

 

[MACTEN]

Fill the bathtub full of water. Unscrew the tank and jut put it underwater. You will see where the leak is coming from immediately. Don't worry about the water entering the tube as it's pressurized and won't allow any water in. Or just fill a large clear jar or glass tall enough to submerge all the possible places it can leak. There is a tiny hole nearer the poppet end. This is the atmosphere hole for the regulator that you need to check as well.

 

[jarmstrong]

Do what MACTEN said,,, also remove the protective cover for the fill port and pressure gauge, to be able to view the leak, if it is on that end of the tube

let us know where you find the bubbles,, it is easy to remove the tank and check underwater, all leaks for the Hortitsia and Kozak can be found this way

 

[orangeokie]

I'm going to follow this chap's advice and see if I can pinpoint the leak.