Changing the fuel breather pipe ?

[Shiz]

Hi Guys

I have a very rusted breather pipe that needs replaced. So far I have been able to take of the filler neck and broken of the old breather pipe, however I notice that the breather pipe connects the whole way to the tank ? does the tank have to be dropped out of her to replace the pipe ?..


Thanks

[Shiz]

Anyone done this before or can offer any help ?

[MrWhite]

The breather hose is rubber and is covered by a thin metal piece where it runs inside the OSR arch, behind the shock. The metal cover is the part that dissolves away but the hose is often perished where it goes onto the top of the tank. You'll know this is the case if you fill the tank right up and petrol starts leaking over the top of the tank. Or lift the inspection hatch and look at it.

I think the breather hose can be changed with the tank left in place but it would be a serious pain in the arse. Where it comes out under the rear seat to join the top of the tank is very tight and it shares its routing with a couple of other small plastic hoses going to the expansion tank. I did it last time with the tank out and it was awkward enough.

If the hose is in one piece you might get away with just replacing the metal cover in the arch. The parts from BMW are pricey too, I'm sure the metal cover was nearly £30 and the hose was about £18, for 2 ft of rubber. That was a couple of years ago...
Although if the metal cover is crumbling away you can bet that the hose will be perished too.

Good luck

[Shiz]

Mr White, I have been able to pull of the breather pipe, as it was just a matter of a few clips, however where the pipe curves up towards the tank and by the looks of it in behind the tank, it seems impossible for me to get at it without taking the tank out. It looks a while lot of hassle for a breather pipe, however safety comes first. The pipe is badly rusted, in fact it has completely broken of . So all that is left is a broken pipe.. Have a look at that pic its something similar :-

http://www.google.co.uk/search?hl=en&q= ... 1024%3B768

though its like a 3rd line running on the very outside.

[MrWhite]

I'm not following you here. I think we're talking about different bits. The link you've posted shows loads of pictures of E30 fuel system bits.

http://bmwfans.info/parts/catalog/E30/2 ... container/

I thought you meant the hose (item 5) that runs under the metal cover (item 21). It seems there is only one small hose that goes next to it (item 7), not two like I had mentioned in the last post.

Is the pipe you're talking about a thin metal one coming down off the top of the tank on the NS? There is a small breather pipe that runs to the front of the car alongside the main fuel supply and return..

[Shiz]

Yes Mr White, that is correct. The small thin metal one has completely rusted away, and basally fell of in my hands. The pipe lead to a small rubber hose at the end of it, which was tucked into the passenger side strut housing. Does this pipe make any sense to you ?

[MrWhite]

Yes, that is a breather that runs from the expansion bottle down, over the top of the tank and along the NS sill to the front of the car. On later cars the metal pipe runs to a charcoal canister in the engine bay which captures the vapours rather than letting them vent to atmosphere.

The rusty bits falling away in your hand can only be accessed if you drop the tank as it runs across the top and joins more rubber hose over on the OS. It has been mentioned a few times in older posts, try the search function.

It won't affect the running of the car if you leave it. Somebody else may be able to comment as to why it should run all the way to the front of the car at all.

What model and age is the car?

[Shiz]

would u know if it would be an MOT Failure or a health & safety hazard. She is an e30 318 1990.. thanks mate

[MrWhite]

I would say no on both counts but I'm happy for somebody to correct me on that. If you remove all traces of 'rusty and broken' fuel lines you're less likely to have a problem come MOT time.

Judging by your other post on inner arches it looks like you've got a fair bit of rust hunting to do. Whats the roof like, or under the battery?

[Shiz]

Thanks man, yeah, there is a fair bit, but the arches are the worst. Luckily the floor pan is clean, was all surface rust. However with reading through numerous threads on these forums, the obvious areas are common on all the e30.. I replaced the rear boot seal there, as it was filling my boot full of water. The morale of the story, i really am tipping toeing around having to take the rear axle, trailing arms, and the diff out. But my biggest worry would be messing up the prop shaft when removing that.

[MrWhite]

You've got bigger worries than messing up your prop-shaft. You shouldn't even have to split it, just remove it in one piece. Getting the rear beam off and tank out will be the focus of your stress. That's before you start poking holes through all the rusty bits.

So if you're taking the rear beam off, tank and diff out; the brake pipes/hoses will want doing at the same time and you may as well change all the bushes, wheel bearings, hand-brake cables and fuel pipes while you're at it.

Have a serious look under the battery, behind the glovebox and around the sunroof. This will make your rusty arches seem trivial.

[Shiz]

Thanks man, ile have a good look. For the mean time, excuse the ametuer but what exactly does that we pipe do ? extract excess fuel when the tank is overfilled ? extract fumes :S..

[parkin10]

that pipe takes the fumes to the engine bay
for cars with a carbon canister - it a emissons thing we in the uk dont have
that pipe was very rusty on my car so i just pulled it compleatly off all the way back to the metal pipe that goes over the top of the tank and left it at that
come mot time my tester has never menioned it

[Brianmoooore]

Breather pipe is not MOT testable. Most of it can be removed permanently with no ill effect, but it should run across to the LH side of the car before terminating, otherwise the car could leak fuel in the unlikely event of it coming to rest on its RH side after an accident.

[Shiz]

Thanks parkin10, that's exactly what I have basically done, pulled it back to the part where it goes up in behind the tank. I just wanted to clarify if it was a MOT failure. I might just attach the rubber hose on the end of the new cutoff, as all I really done was shortened it from the passenger front to the passenger rear arch. Thanks