Sub fuel tank how does it work

[lars04]

Gday can someone explain to me how the sub tank works in a gq the other day I filled my tank to the brim and fuel started to leak all over the ground, would it be leaking from a hose that's meant to be going to this sub tank? How does this thing work?

[Mc4by]

I don't know why it overflowed but I got advice from the guys here that you push the button when the main tank starts to reduce. It pumps fuel from the secondary into the main tank. You can't choose one or the other.

[GQtdauto]

Sons GU had a hose missing from the filler neck so when filled it spat fuel until he found it .

[lars04]

Sorry should have said I have a gq there not the same set up as the gq.