Help: Pressurised fuel tank

[Dan Stanley]

The fuel tank on my nova seems to be under pressure, when I take the fuel cap off its releases it. Its making it leak from the weakest fuel line joint, etc. The tank is the external fuel pump type (GTE/GSI), the car is a saloon, the engine is a X16XE. Ive replaced the fuel tank with another (pattern part) tank but it still does it. The only thing I can think of is that the fuel pump is to powerful (cant remember what it was from, either a 1.4SRi nova or a 20NE mk3 cav) or its because Im not using the fuel damper (the thing that sits immediately after the fuel pump) since it broke.
Any ideas people? Anyone had this problem before?
I did try connecting the fuel tank vent valve that runs with the x16xe but it didnt make any difference. The vent pipe on the tank isn't blocked either. Might try replacing the fuel pump/damper unit next, to see if that helps

[Graeme]

I've never run a damper and the vent pipe on that runs around the rear of the tank and is open ended should release the pressure ideally

[AlexW]

You sure the breather hasn't got a kink, It cant pressurize if it hasn't?

[C612DNM]

Sounds like the vent/breather pipes are blocked/kinked.

[Dan Stanley]

The vent pipe wasn't blocked last time I checked it. I'll check over everything again next time I get a chance. If I take the rubber seal off from the inside of the fuel filler cap then its fine, but Im worried that maight let water into the fuel filler neck when I wash the car.
:confused:
Theres always problems when playing with old cars, but then I suppose that sorts out the good cars from the bodged ones!

[Mike]

The breather pipe is definetly blocked or kinked without a shadow of a doubt.

[Will F]

Short term fix/bodge is to drill a tiny hole in the cap..

[mowgli]

the breather pipe is only getatable with the tank removed. the filler vents have nothing to do with the tank venting, & are only there to aid filling.