We double O ring the P/V bearing, but they still seem to leak, this bearing holder also has an O ring on the outside.
    Part of the problem is that O rings need to set against outer wall and shaft to seal, I called up Dez and told him I had an extra P/V bearing holder and popped out the bearing and did some measurements, the bearing itself is a 21mm x 12mm x 5mm, then there is a step cut that just 17mm x 5mm that holds the O rings, now here is where the fun happens, the P/V O ring are 12mm ID x 2.5mm wall that should be 17mm OD, well I measured three of these O rings and every one of them were under 17mm, the wall thickness varied from 2.42mm to 2.48mm using a 5 digit micrometer, an air leak only needs a .001" and some pressure to happen.
    I told Dez, hey let me order a few O rings with 3mm wall and see what happens heck we might get lucky on some cheap coin here, also said I would call a few bearing house's and see if a mechanical seal (17mm x 12mm x 5mm) would work or not, or if such a seal does exist sure could also be a cheap cure .