I found a pipe at the rear drivers side hanging down, its a clear rubber tubing with a rubber trumpet on the end, and i couldnt see anywhere for it to connect to... I was told it was a fuel breather or something?

If so, what does it do? And if it isnt that, what could it be? Sorry to be a noob but i want to understand how my car works!

Also sorry for the lack of pics, can't upload them on the work PC...

I sounds like the breather. It does a few jobs, but the main two are that it stops pressure building up on the tank on hot days and lets air into the tank to replace fuel that's been used. .

the above answer is perfect!

the onlly exception to this is cars which have an evapourative emissions control system to absorb fuel vapours, in this case it is connected to the charcoal canister

Yeti knows it all! Cheers dude

Whats the charcoal canister do? Thanks!

The charcoal canister is for emmitions.. or clearing the fuel emissions from the air passing through it.. or something like that...

What I want to know is tho... When the cannister is removed, Do you block the clear tube or leave it to breath?

Ideally leave it to breathe. You can remove the pipe altogether and replace it with a mk2 part whcih is just a short pipe that connects to the gravity valve on the filler neck.

If you have a mk3, the pipe you have found skatty isnt the breather for the tank, it's an overflow drain for the filler neck rubber seal. When the fuel tank over fills it collects in the bottom of the rubber seal around the top of the filler neck, there is a hole in the bottom that this pipe connects to. If you have a mk2, it could be either the this or the tank vent as mentioned above.

the charcoal canister merely stores the fuel vapour in little granules of charcoal.. during normal running, particularly on idle and warm up, a valve opens which purges the vapour into the intake tract of the engine so the vapours get burnt along with the air/fuel mixture.

as has already been said, you can disconnect them, i allways disconnect the end which is closest the fuel tank and then put a miniture breather filter on the open end of the pipe

Cheers gaz, the does sound a little more likely - it did look like it was supposed to connect to something... I'm guessing its gona be a bitch to refit!

Still, worth a try. The bastard ran out of MOT so its sat on my drive awaiting a new engine. Guess I've got the time to piss around with it!

the trumpeted end is supposed to just vent to air, just tie the pipe up somewhere if it's just dangling about.

If you remove the charcoal canister, definately leave the clear pipe left over to vent if you block if off the tank can't breathe properly.