Originally posted by Sow&Steady
Bleach, this has always been one of the issues for the 705. The best is to use the new translucent o-rings which Serpent has released. I don't have the part number handy but I bought a set, replace the old ones and presto! 
Which translucent O ring is this? Do you mean the new purple O rings? I think the newer batches of the 705 already included this as a standard. That was what I noticed. Part number is 909407.
bleach1, I think your problem lies in the piston having small plastic flashes. You need to smoothen them out. Look
here for the shock building tip. Ignore the alloy shock seal part as this is not required anymore with the new type bladders.