Canadian Airgun Forum

I am trying to trace down a very slow leak without tear down or immersing the gun in soapy water. To Quote Mr Scott: "The more they overthink the plumbing, the easier it is to stop up the drain." In this case it's to make it leak, but same idea.
It's a regulated PCP aftermarket conversion for the 2240. I put a balloon on the muzzle and one over the high pressure gauge end and put soapy water around the low pressure gauge threads, no leaks detected at those 3 spots. The tube only hold around 50 cc and the symptom is it leaks from max pressure 3500 psi to regulator pressure 1000 psi in about a month, then it hold steady at regulator pressure. Where in the chain of seals could the leak be?
I believe the bolt seal to the breach may not be 100% effective so just because the muzzle balloon doesn't inflate is not 100% proof that the valve isn't leaking. But if the valve was leaking then the pressure should drop to zero over time, which it doesn't; it bottomed out at the regulator pressure. It could be a rate thing where the rate of leak is dropping slower as the pressure drops and if I wait longer then the pressure will eventually leak to zero, but I did find it odd that it leaked basically to regulator pressure then held. Any ideas?
It is this gun:
download/file.php?id=37883&mode=view

_________________

))))----//----------==
Age quod Agis, et semper ubi sub ubi.

Sounds to me, the leak is at the fill seal, Duke.
I had a leak in 2 carbon tanks I bought, filled to 4,500psi and 4,300psi then both deflated to 2,500psi. After 6 months, they were still both at 2,500psi, so I filled them again
to just over 4,000psi and they both held.
One of Gord's Talons did the same. After re-filling, it was find.

_________________
Best Wishes
Daryl

Hmmm, fill seal eh. I *think I eliminated it when I put the balloon on over the end of the tube .. I included the filler hole in the neck of the balloon, so the balloon covered the hig pressure guage the gaude threads, the end block joint and the filler hole. There was zero inflation of the baloon so that end seems sealed and secure. What I'm leaning towards in the low pressure gauge itself, it's the only thing makes sense to me, Of course the gauge doesn't know what the regulator is set to, but perhaps it's just co-inky-dink that it leaks approx at 1000 psi in this case.

_________________

))))----//----------==
Age quod Agis, et semper ubi sub ubi.

I have always wondered about those small pressure gauges as well? I mean, they are relatively inexpensive for the high pressure they are required to hold?

What gauge can you really trust, the one on the gun, hand pump, or the compressor?

Edit! I know my comment was no help to your situation.

_________________
Once you replace negative thoughts with positive ones, you'll start having positive results.
- Willie Nelson

"If our freedom is taken, the American dream will wither and die."
- Rand Paul

I've dunked the gun, with trigger assembly removed, just the pressurized portion. A WR100 leak didn't show up by buttering clear silicone grease over openings and joints, so off with the toilet tank lid and dunk. Adequate drying isn't, of course, rocket science when one has shop air, alcohol, etc.

_________________
Slavia 618 .177
Webley Senior .22
Jelly SUPER 4.5 mm
Webley Viscount .177
Crossman 1377 Classic Pump .177
Diana Stormrider2 .22
Kral Mega Marine Walnut .22
Artemis PP750 .22
FX Streamline .22 walnut
FX Streamline .22 composite

Hi Duke.

I would be interested by what your problem is because I discovered that one of my CZ200T is dropping the pressure to 90 bars and stays there.

I found it when taking it out for testing with my plastic pellet. Since then, whenever I filled it up before storage the next time I got it out the pressure was down to 90 bars.

R-Gun Pete

I dunked a tube with a gauge once before, and of course the result is the gauge face will fill with water, it isn't watertight so I am not going to do that again. It seems there is a "trap door" somewhere that leaks above a certain pressure. I may try a different gauge, or jut plug the LP guage hole and see if it holds - then I will be able to eliminate, or not, the LP gauge. CZ200 is not regulated, so I may be barking up the wrong tree, I guess any O ring or seal back of the fill port could be the culprit, and there are many.

_________________

))))----//----------==
Age quod Agis, et semper ubi sub ubi.

Hi Duke.

Thanks for the reply. I guess I will have to open the tube to see what is wrong.

It is another project for the summer.

R-Gun Pete

The first thing that I would try is to replace the regulator piston o-ring.
The belleville washer stack usually has a bleed hole to atmosphere, and the air is likely leaking past the piston o-ring and out through that hole.

Thanks, I was afraid it could be something like that. Oh well, teardown seems inevitable.

_________________

))))----//----------==
Age quod Agis, et semper ubi sub ubi.