Mk3
 

So it's leaking from the o ring?

Grab a towel and a flashlight and you tell me. There are three places it can leak from: Where it's pressed into the block, at the middle union (where there is an O-ring), or the very end of the dipstick tube.

Mk3
 

So it's not leaking from the union because before the rebuild it wasn't leaking but I think it's leaking from the little o ring that at the end of the dipstick tube and that's the thing that goes to the union