Fuel line help

[Lunadog]

I have a fuel pipe on both sides that goes from tank up in to the area where air is vented(ears) the seem to fit in to a cylinder 25dia x 150 long . Which is an area that’s unserviceable.
Can anyone enlighten me as to their purpose

 

[sparkywig]

That's the fuel tank breather system. All the rubber parts (no. 24) rot causing fuel fumes.

 

[Lunadog]

Thank you, I have not seen that schematic before. what are the tubular items?

 

[Earlybay1]

Expansion vessels for fuel when a tank is full especially in hot weather .

 

[mike202]

I think they are there on later bays because of 1970’s environmental concerns as early bays don’t have all that pipes set up.

 

[Lunadog]

thanks, so are they needed nowa days

 

[mike202]

The problem for you is Earlybay’s have the tank vented to the filler as in the schematic drawing. Later bays don’t have that, but have the elaborate pipe set up instead. I’m not sure if you can remove them. I have a 70 Earlybay, so maybe someone else will be able to comment.

 

[sparkywig]

They're expansion vessels and fuel condensation separators.
Earlier buses vented the petrol tank to atmosphere by the fuel filler, which is why they've often got a fuel smell when the tank is over 3/4 full.
Later buses have the expansion system which also prevents fuel fumes escaping for emissions purposes as well.

 

[Blackpony]

What vent system should a 1972 Bay have? Is there a VIN date when the systems were changed? Thank you.

 

[sparkywig]

What vent system should a 1972 Bay have? Is there a VIN date when the systems were changed? Thank you.

Model Year 1972 from VIN 2122 000 001

 

[fatgaz]

I have a 1971 crossover built for the US market and mine has a pipe venting ststem on the tank.

 

[Earlybay1]

thanks, so are they needed nowa days

 

[Earlybay1]

From the expansion tubes the pipes in the engine bay should connect by a T piece 15A which goes to the air inlet plenum after the factory air filter. The negative pressure in the plenum draws fuel vapour from the tank to the carb and stops it escaping to atmosphere (and smell!) It is an engine out job to change all the rubber hoses (24) as they will be behind the fire wall. Get them changed asap because if they leak then there is an extreme fire risk. If you have the factory air filter setup which is not as nice looking as a pancake but is superior keep it. If not connect the fuel vapour pipe 9 to your pancake by attaching a small adaptor for the pipe to the cover to fit 9 to OR locate the open end of 9 as close as possible to the air filter.

 

[sparkywig]

I have a 1971 crossover built for the US market and mine has a pipe venting ststem on the tank.

Was it built in 1971, or is it a 1971MY?
Model Years run from August to July, so a 1971MY can be built between August 1970 and July 1971, a 1972MY between August 1971 and July 1972.

 

[fatgaz]

Was it built in 1971, or is it a 1971MY?
Model Years run from August to July, so a 1971MY can be built between August 1970 and July 1971, a 1972MY between August 1971 and July 1972.

Hi,
It was built August 1971 and shipped to Boston USA 3 September 1971. Hope it helps

 

[sparkywig]

August 1971 is a 1972MY, 3rd digit of VIN should be a 2. (2*2* *** ***)