Trying to help a freind with an Aeron Spider pistol

[whitefox545]

Hi! All, I'm trying to help a friend out who bought a used Aeron Spider PCP pistol used a few years back, he said it has always had a slow leak from the day he bought it and that it would hold air long enough to shoot it but would loose its air fully in a couple days. I told him it was probably only an o-ring or something simple and that I was sure I could probably fix it for him.
I aired up both of the cylinders and checked them for leaks and found no leaks that I can see so I tried to thread them onto the pistol. Just before the cylinders get to were they seat to the regulator(I'm guessing) most of the air escapes from the cylinders??? Am I doing something wrong ? I have searched the web for info on this pistol and there is VERY little Info available about it and what I did find was not favorable about this gun. It looks to be a decently made piece, maybe not as nice as the top of the line guns but not terrible!! Hoping to find someone that can offer some incite as to what to do or check, I was going to remove the regulator next and take it apart and see if I can find anything wrong in there. I'm no airgun expert but have a fair amount of experience resealing PCP's and installing regulators and such so I'm not a complete rookie.
Thank you in advance for any advice you can give, J.L.

[batty]

Have you tried cocking it (leave the breech open) and then screwing the cylinder on?

Is the regulator visibly damaged?

Do you need to screw it on fast to create the seal?

[Gwhite]

I'm not familiar with exactly how the cylinders seal to the pistol, but the symptoms are consistent with a blown seal at that interface. Because both cylinders leak when installed, I suspect the seal is on the pistol side of things. I couldn't find an exploded diagram, but it's probably a dead/missing O-ring, and should be easy to fix.

[whitefox545]

Batty, Thank you for the reply!! I cocked the pistol and the cylinder went on without any problem!! I should have thought to try that as many rifles cant be charged from empty till you cock the hammer spring as the spring keeps the poppet open and it wont seal to fill the chamber. my friend says it will leak down in a couple days so I will let it set and keep a check on it now. The seals were a little dirty but otherwise look to be fine (never know though)
They are not O-Rings but are flat black seals of some kind or at least they appear that way. the gun is a 2006 and as far as I can tell and it has been opened up in the past, I can tell because some of the fasteners are a bit damaged from cheap Allen wrenches and in one of the regulator screws the head is stripped out but I will deal with that after I see if it is still leaking with the cylinder attached. may have just been (hopefully) dirt on the seal causing a slow leak?
Not much Info out there on the pistol that I can find but it looks as if it was at least decent quality but defiantly not top of the line in it's day? We shall see!! Again thanks for the help!! J.L.

[batty]

Happy to help

[whitefox545]

after getting the cylinder to go on without loosing all of its air I decided to shoot the pistol a few shots in my basement range, after a few shots ,maybe 35 the pistol instantly lost all of its air pressure from the connection were the cylinder threads to the regulator. I then attempted to install the other cylinder and it released most of its charge while screwing it to the pistol even with the gun being cocked!! I think this thing has more problems than first thought!! one thing I did find is the probe end of the regulator that fits into the cylinder is a bit longer than the probe end on the charging fill fitting so I would think it is opening the intake from the cylinder sooner than the fill probe as you thread it to the cylinder so that may be the reason for the release of air when threading on the cylinder? It is opening the valve before the thing is seated on the seal ? any input anyone? Thanks for all of your help so far!! J.L.