Fuel Tank Breather Hose

[Lofty]

Advice please..!

I am replacing the old breather hose and was wondering if there is any specific grade / type of hose that I am to use?

Also, my fuel tank has two breather connections, one either side at the rear / top of the tank. Past owners, for whatever reason, have connected the two via a T piece, so that it is effectively only one breather. Are there any problems with this? If not, can I 'blank' one of the connections and just have a single hose run to the breather port?

Regards

Mark

[Searider]

ISO7840 hose.

Not sure why there would be two breathers - unless its to allow the tank to fully breathe when the boat is heeled over?

[Cypman]

Hi
The two tank breathers are almost certainly to deal with the boat not always being level. If the boat has only one breather on one side of the tank and the boat is heeling (even slightly) that way with a full tank of fuel, any heat expansion will cause the fuel to pour out of the vent pipe. Consequently, I would suggest a T Piece, rigged above the level of the tank vents, with a single pipe then to the vent fitting. Use good quality fuel pipe of an appropriate diameter remembering that if you use too smal a diameter it will make tank filling difficult and messy as the air being displaced by the fuel entering the tank must be able to get out of the tank at at least the same rate!!!
Finally, a 360 degree vertical loop in the vent pipe between the tank (or T Piece in this case) and vent has been known to reduce the liklehood of fuel being forced out through the vent. Hope this helps.