Tried doing a search on this one, couldn't find anything specific enough. A buddy of mine has an AAZ and his pump is leaking diesel from the LDA vent( AKA the black rubber gromet) on the back of the pump. I've heard of this happening before, but what actually causes this?? Can it be fixed without taking the pump off the car???
Its a small o-ring that is causing the leak and its a very common leak on the VE pump.The top half of the pump needs to be removed to then disasemble some other componets in the top to access the o-ring.Once one seal or o-ring leaks its time to replace them all otherwise the next weakest link will provide another leak soon after !!
The bosch seal set with the o-ring for this is,... I think the DGK-121

It will have a shaft seal for a larger pump so you might want to buy the right shaft seal and do them all.
Thanks for the help guys

We took the top half of the pump off and found out the O-ring that we were given was a little bit too large for the pin that moves horizontaly, are the O-rings between an mk2 pump and mk3 pump different?? So yeah we ended up being back at square one.............