What is the best way to deal with the breather system? On the donor car a pipe goes right to the front into a carbon canister then into an electrical valve and onto the inlet manifold. The Mk2 tank has a valve of sorts moulded into the neck with an inlet and nowt on the outlet. I'm not sure if it has a hidden connection into the tank too. Pictures of these parts are in this thread.
Cheers, that seems to be the way given the options. There was/is quite a vapour smell around my Mk2 tank once I removed it so it must be pretty much the same as an open vent.
when i do this i will have both tanks side by side and mod the mk3 tank till its liek the mk2. not sure how though as ive never seen a mk3 tank yet
I wasn't sure you could do that, but looking at it again it's perhaps simpler than I thought. Mk2 tank: Gravity valve direct into Mk2 filler cap shroud, breather valve to black pipe to 'on neck' connection Mk3 tank: Gravity valve to black pipe, breather valve capped off no connection. It should be just a case of taking the black pipe off of the Mk3 gravity valve, rotating the gravity valve outlet around to the Mk2 position and connecting it to the pipe on the top of the Mk2 filler cap shroud.
What does this actually do? I'm wondering if I best change mine to the MK2 setup. If it's not dangerous i'll leave it as it is seeing as it works on the MK3, and MK2 is pretty much the same!
sounds plausible, if it works pics please on the mk3 fuel tank fumes are vented to the carbon canister and valve, on the mk2 they're vented to air? wasn't sure if the mk2 has some kind of valve in it rather than just having the pipe open to air. I've not looked at one in detail
As it happens the Mk3 gravity valve is situated too low to connect like the Mk2 so I did it like this. The pipe is actually rising all the way although it doesn't look like it from this angle. A correction on the Mk3 breather (which is the pipe/valve opened by fitting the cap) it isn't capped off, it vents internally. The fit isn't quite the same and the fuel gauge will be off apparently under reading, but at least its running again for cheap. I won't be leaving the car standing with post RTFO V-Power in the tank again. Not only did it rust the old main pump and new OEM main pump the vapour affected things in the tank too. It turned the rubber connected to the lift pump and exposed lower part of the top seal to a black paint like goo. Probably not much in it, where VAG have done it on mostly older vehicles they use an end piece which looks like a little rubber trumpet. They do seem to be routed further away from connections though.
