Fitted a mk3 fuel tank to a mk2 1.8T. The breather pipe on the tank, can I just let it hang open ended under the car? Cheers
Looking at the diagrams of both Mk2 & 3 tanks I`d say NO ... as you need to retain the `gravity valve`and return the breather to the fuel filler. My understanding of how this works is ... it is a non return valve that prevents fuel spillage should the car / tank be inverted. I would also assume that this would be required by vehicle law / regulation. Are you using the Mk2 fuel filler system ... can you connect the breather pipe to this gravity valve ? Mk3 - gravity valve is `29` Mk2 - gravity valve is `29`
Thanks for the response. I should prob have been clearer.....I have the valve, item 29, I was going to connect the breather hose to this and then just run it to the base of the fuel tank and let it vent to the atmosphere there. As I understand it, the breather would normally run all the way back into the engine bay and through the charcoal canister before going back into the engine. I also believe this is just for emissions, right? Are there any problems with what I'm suggesting? What have others done?
Not as long as the valve remains in it`s `high point` position and it`s outlet can not be blocked somehow ...
I fitted a fuel filter to the end of the vent hose on my Mk3 tank into Mk2, think it was less than 1 from GSF
Interesting you should suggest that actually as I have a one sitting about that I was thinking I'd just attach to the end of the breather.... Think that's what I'll do as well. Cheers for your help everyone!
Could smell fuel and saw this up in my wheel arch. So this is (part 4 in Mk2 diagram) the fuel filler and the pattern/smell circled on the in arch underseal suggests I'm losing fuel out what I presume is a breather. I will take the wheel off next weekend and get a proper look but let me ask a stupid question - is that (green arrow) supposed to vent to atmosphere or be connected to something? None of the diagrams/manuals are clear! The other side is connected to the gravity valve! Tank is 7/8ths full. Either way I'm sure it shouldnt be pissing fuel into the inner wheelarch! Any help appreciated (91 16v)
Final post tonight I promise. The diagram for the rubber filler neck seal on this website suggests it connects to atmosphere... https://www.werk34.de/en/rubber-surround-for-fuel-filler-neck-fit-golf-mk2-201.191.253-b.html So that begs the question what is backing up fuel into the filler neck and making it spurt out? Any ideas?
that lower hose outlet on the surround is just a drain to let water out, are you sure the damp patch isnt just a bit of moisture? if you have fuel coming out of the drain here its either you spilling a bit when toping up the fuel, the cap leaking or fuel getting out the breather going to the upper connection on the surround and dripping down. its normal to smell fuel around the cap though this is the usual fuel vapour breathing out the tank
Thanks Rubjonny, positive it was fuel! Will get that wheel off this weekend and have a good poke around. Possibly me being cack handed with the Optimax pump but sure there's something weird going on
