FX another month another panthera leak.

It's been so good for the last 5 months, holding air with no problems at all.
However today I depressurised it to change the reg gauge to a digital one so I can properly look at my regulator cycle times (still 5 seconds even with a huma).
On repressurising its now pouring air down the barrel.

This must be the valve / seat if I am correct? I've put a couple of pellets through to try and get it to re-seat but no joy.
(It had the upgraded ones and has not been dry fired)
 
It's been so good for the last 5 months, holding air with no problems at all.
However today I depressurised it to change the reg gauge to a digital one so I can properly look at my regulator cycle times (still 5 seconds even with a huma).
On repressurising its now pouring air down the barrel.

This must be the valve / seat if I am correct? I've put a couple of pellets through to try and get it to re-seat but no joy.
(It had the upgraded ones and has not been dry fired)
How did you degas it?
 
Just my 2 cents -

It sounds like a stuck open valve to me. A quick check would be to push in the back of the valve pin that you can see in the hole in the valve holder (part 1 below.

Panthera Valve.png


If that doesn't do it you likely have a damaged valve gasket (part 5) and may need to replace the valve pin (parts 5 & 6 combined).

It is easy to pull this assembly apart and check. Just pulling in apart and putting silicon grease on the o-ring (part 2) will make the valve smoother.

Cheers,
Greg
 
Thanks Greg, I originally replaced the valve with the newer version and the newer holder- part1 (a year ago now)

Just looking for confirmation that it’s the valve before stripping it all down again, Pretty sure that’s it and sounds like that’s the consensus so I’ll crack her open again!

After trying a simple reset first (still a pain to take the sabre rail off to do that!)
 
  • Like
Reactions: NAProf
What happened to the end of the valve stem? Looks like a deformation/burr caused by some kind of tool strike. Im not familiar with the Panthera, but that seems like it might cause the valve stem to stick or drag in its bore?
I didn’t notice that until you said. Not sure that is causing this leak but I’ll have a good look at it when it’s out 👌
 
  • Like
Reactions: MongooseV8
So I stripped it down and everything looks, well just fine.
Interestingly this valve stem and also the original valve stem both have that mark, I’ll try and get a photo of it.

I changed both rings on the valve seat while I was in there but no change.

Could this be one of the barrel rings?
From memory one of those going could cause the same behaviour of leaking down the barrel but I might be incorrect on that.
I might have to take the lock nut off and work out if it’s coming down the liner or down the outer
🤔

Regardless I’ve also ordered a high impulse valve stem for it which may solve the problem!

The fact it dropped to 10 bar then stopped is interesting as that’s still a fair bit of pressure.
 
I’m so done with this rifle.

It has to be the valve but everything looks fine to me… it’s very strange that both valves have the same mark on the front though.

I checked the block in front of the valve and the hole is bored all the way through to the screw… so this could be the valve stem hitting the screw thread?
I have NEVER dry fired the rifle though, because I am aware of the problems of doing that.

Anyway stripped it right down, changed both o-rings in the block around the barrel, not a task I ever want to repeat…. Double check everything around the valve and…… still leaking down the barrel, about a bar every few seconds

IMG_1276.jpeg
IMG_1275.jpeg
IMG_1274.jpeg
 
Reminds me of a shade tree mechanic, throwing parts at it until one sticks/fixes it. If you're not sure, send it to your dealer. Take off the barrel and stock and ship it off.
Yeah unfortunately we don’t have that luxury here.
It’s classed as a firearm so can’t be shipped. It can’t even be exchanged for another one without about a 3 month wait on the paperwork.
If this was not the case it would have been back to the dealer when it arrived with leaks.
But thanks for your help anyway
 
Did you check the one o-ring in the block that seals around the rear of the valve body. If that's bad, air will leak out the barrel. Also make sure the valve assembly is indexed properly and fully seated.
Thank you, I’ll double check that one.

I did check the seat was correctly indexed and everything was seated properly 👍