say you have pressurised the system with a compressor to (rated spings psi), youve removed the DV from the TIP (but still bonnected to boost pipe) and can feel air leeking to the tip..
though, i disagree with what you are doing guys, soon forge will get wise to people taking the piss, forge are expensive enough, you should have to pay when things really do go wrong!.
then i suppose if they dropped their prices a little their customer services would deteriorate too. 
The old type piston leaked no matter what so in my opinion its not fit for use,
I don't see why I should pay £14 for a rebuild kit with the revised piston design as I had only recently paid £117 for
the valve.
I now have £14 to spend of something else.
Their customer service is excellent and they recognize they had an issue with the old piston design,
