Quote Originally Posted by Discocom View Post
Many thanks for all the advice. I wonder if the cylinder was slightly overfilled, which caused the problem as working fine now.

I have a second cylinder but need to replace the seal as old one was hard and came out in bits.

Does the seal need to be a green one, as my understanding is that it has to be resistant to co2?
The colour's not important, Seals are often coloured for the industry they are used in (ie green/blue are often used in the food trade) you will need either polyurethane or Silicon for CO2, If the seal is to be moved on a regular basis (ie Cylinder to pistol seal) you will need Polyurethane as silicon will be too soft. Protek may have some but failing that Kent Bearings and Seals in Rochester or Seal Force, You'll get a pack of 10 for about the same price as one from Walther, Brand/colour isn't important at all, an O ring is an O ring as long as it's the correct material & size.