'79 MGB Fuel Pump Vent Line?

["Sean Johnson" <sean_johnson@milacron.com>]

The question about fuel pump odor reminded me of something I saw while 
reviving the pump on my '79 MGB:

Aside from the fuel suction and delivery lines, there is a small clear 
plastic tube that attaches to the pump.  This runs forward with the other 
fuel lines, but I didn't see it coming forward to the engine compartment.  It 
wasn't important at the time, so I haven't traced it yet.

Anybody know what this line is, and what it does?


thanks,

Sean Johnson
'79 MGB