Air Arms Owners Club

Hi I have recently purchased a good but quite old S400 my first Pcp it shoots very well, I pressurised it to 190 bar on the Sunday and by the following Sunday the pressure had dropped to 100 bar has anyone any ideas or a strip down manual to replace the seals thanks

What's your location? Add it to your profile, there may be a member near by who would be happy to guide you through it, all the parts you need are easily available from Julian, Bgaltd on here, the link to his website is at the top of the index page.

One of the most common faults is the filler valve , tape a balloon over the top and leave it for a while, if that's where it's leaking from, the ballon will inflate, simples, then do the same with the barrel, ext

The baloon trick ....

1. Pressurize back to say 170 bar. Push the bolt all the way home and pat it down
2. Slip a balloon directly over the barrel and tie it firmly - i.e. without the silencer.
3. Take another balloon and put it firmly over the fill adapter.

Finally, get some soapy water and put it around where the aluminium dog leg for the gauge meets the action.

If you get the barrel balloon inflating, it is the firing valve not keeping the air in.
If the fill adapter end leaks, it is the seals at the filling end.
If you get bubbling near the gauge mount, it is the seal between the aluminium body and the action. Frequently this is the culprit. If the seal is not too far gone, it will hold for a bit if you tighten the screw holding the gauge mount but eventually, the seals will need replacing.

Julian, who runs this site (company is called BGALTD or Bond Gun Accessories Ltd - Google it)) will sell you the genuine spares you need for a very reasonable cost - the seals are literally pennies. Good luck!

Hahaha .. I just took longer to tyoe the same thing

Raj wrote:Hahaha .. I just took longer to tyoe the same thing

Ha ha, great minds!

However your description was a little more detailed than mine.

Extra points for efforts there.

Good advice from the guys above. It'll be a slow leak that can be worsened by cold temps.
It'll be very easy to fix in your case as your rifle should (hopefully) be pre anti-tamper.

Hi guys
Thanks for the great advice, did the balloon trick and found a leak where the male filler screws in to the bottle on the gun i tightened it slightly which seems to have cured the problem at the moment, but i presume there is a seal there which will need replacing.Is it worth stripping and replacing all the seals? as it is a 2004 gun
regards dave

12 years is a good innings for rubber components under very high pressure. A new set will cost you not a lot from Julian who runs this site Give him a call!
http://airarmsspares.com/