Ruger Blackhawk problem after Vortek PG2 kit installation

Hello Everybody,
I'm a new member and have some questions.
I have installed a Vortek PG2 kit with the red seal. It was fairly difficult to insert the piston with the red seal into the compression tube - I had to use some force.

Now when I fire the gun, it has a fairly sharp and loud crack, but the pellet only spits out from the barrel to a few meters (it actually once even remained In the barrel).
- What may be the problem?
- Is it the seal not installed correctly on the piston (or maybe it even became separated)?
- How do I know if the seal is on the right way when I install it on the piston? I put it in hot water for a few minutes, then pressed on the end of the piston. How far should it go on?
- Should I put some lubricant inside the compression tube when reinserting the piston? (Dieseling?...)
- If I need to buy a new seal, which one should I get? Is there a Canadian distributor?

Thank you for answering all these questions in advance!

Las

Never mind guys, I found the problem: I installed the piston seal the wrong way... Doooh :-( I don't know if this has happened to others, I feel stupid enough, regardless.
The seal was tight up against the bottom of the compression tube - it was also a nice play to get that seal out from there )a 1-2Á dowel and a piece of a straightened coathanger wire with a 90 degree sharpened/flattened bend at the end did the trick.
And now, onto the new seal.
Any tips where to order from?
Thanks in advance,

Las