fuel line breather hose why so long?

[cschollum]

im just replacing my fuel lines from the tank and i see there are 3 going the length of the car, with one just ending in the engine bay unconnected, im presuming this is a breather hose? why is it so long? i dont want to have to replace the whole length if i dont need to, can I shorten it?

chris

[Scott H]

that is the line that is supposed to go to the charcoal cannister in the engine bay

I'm not entirely familiar with M20 set up though


im just replacing my fuel lines from the tank and i see there are 3 going the length of the car, with one just ending in the engine bay unconnected, im presuming this is a breather hose? why is it so long? i dont want to have to replace the whole length if i dont need to, can I shorten it?

chris

[Scott H]

The diagram for the charcoal cannister is in a different place. The lone line from the tank picture to the canister is probably the third line you are seeing

http://www.realoem.com/bmw/showparts.do?model=HC13&mospid=47402&btnr=13_0189&hg=13&fg=15


thanks, in addition ive looked at the etk, and it shows only 2 lines , inlet and return, so as i havent yet removed the tank i dont know if the 3rd hose is connected anywhere, but if as you say its for a carbon filter and mines before that time, looks like i only need replace 2 of the lines

[Scott H]

Do you have the vacuum operated valve that is Part #1 in that picture?....which would subsequently be connected to your intake manifold? This allows the fuel tank to vent at ambient air pressure and fuel vapors pass through this line. The air is sent to the intake manifold under vacuum pressure and mixed in as part of the air charge.

When the engine is not running and the intake is not creating vacuum, fuel vapors pass through the tank vent line and collect in the charcoal cannister. They are sucked in with the air charge on the next engine run and burned. This is a pollution control.

I'm not familiar with the M20 at all so I cannot recall exactly what is under the hood.


well i dont have the charcoal system, what does it do?

[632 Regal]

does it smell like gas if you sniff it? (dont suck it like a straw)

[angrypancake]

light a match and see what happens?

[dacoyote]

does it smell like gas if you sniff it? (dont suck it like a straw)

I would suggest holding a match or a candle up to is so you can see what you are doing...

[632 Regal]

no way dude! that could be dangerous...melting the rubber could drip onto the valve covers or something.