Petrol Tank Question

[Weathers]

Having brimmed the tank on Sunday after a spirited drive I had petrol pouring out of the top of the pipe shown. The pipe runs parallel with the fuel lines but terminates about a foot and a half from the tank. There is just an open end here.

Is this normal as some kind of overflow or have I lost something stopping the petrol escaping?

It was fine once the petrol level had dropped after a few miles.

All help appreciated.

Chris

[David T]

That red valve at the bottom should stop the fuel coming out, especially if you are trapped upside down in your harness. Perhaps it is faulty.

https://www.newton-equipment.com/tank-v ... alves.html

[Weathers]

Thank you David. I'll have a look at it tomorrow but it definitely wasn't stopping fuel coming out despite the car being the right way up!

[Tony C]

I think the valve should allow the tank to breathe assuming the car is the right way up! So it will vent fuel too. The ball bearing will seal the vent if you're upside down, which hopefully you'll never need to test........Perhaps replacing the hose with a longer one pointing downwards would help, at least you wouldn't know its leaking!

[andyf]

The TPV8 version will stop overflow so long as the positive pressure in the tank is less than 0.05bar (check the pressure). It looks like quite a clever little valve.

I might get one. Winter upgrade #1

[David T]

I thought it wouldn't vent fuel as one of the balls would float to close. My memory might not be good though.

[Weathers]

I've brimmed the tank many times before and on occasion to the point that the fuel has pissed out of the filler and down the body work (most annoying) but it's never come out of the tube before and certainly not kept dripping and dripping for a good while after. Hence, I think something has stopped working, perhaps the balls in the valve have got stuck or something? I don't know, I have no real idea.

Incidentally it made no difference to the leaking if the engine was on or off.

Will investigate further.....

[andyf]

I'd take the valve out and see of you can bow through it in both directions... also some carb cleaner might help is it's got gummed up.

[Weathers]

This might sound daft but.......

........I've shaken it really, really hard and there is clearly limited movement internally. Blowing through it to test is tricky as there are 2 holes (1 either side) recessed into the surprisingly deep threads (just next to the bolt bit) so blocking them to test the in and the out holes is a complete mare. There is some flow in and out but looking at the tech spec I wouldn't be able to tell if it's the desired 0.6 or 0.8 l/sec!

Given it's a safety item I've ordered another so will see how that goes when it arrives hopefully tomorrow.

I will clean up the old one and if it is ok keep as a spare. Certainly needs a new o-ring or mini gasket or whatever it's called.

Thanks all for your help and suggestions.

[pigeondave]

A good way of blowing air through pipes is to use a little electric wheel pump with the lilo attachment fitted.

Got me out of major poo on tour one year (I ultimately had to retire).
Turned out that the extended midget tank was rusting from the inside out