There are openings at the bottom of the tube, I think, so that petrol can get into it from the sump. I haven't actually seen what's there properly as I didn't have a boroscope camera when I did the 405 tank - it would have been useful to have a good look around. If you put your water feed into the top of the tube and the water makes its way into the into the rest of the tank, then it isn't blocked there. Or just put the drain plug back in, add some water to the tank via the main petrol filler pipe and check that it also rises in the tube.
|