Fuel tank

[stevo123]

Hi all , im a little puzzled should my fuel tank create a vacume . When i undo my fuel cap a get a massive rush of air going into my tank. Oh its V8.
Is something blocked or are they all like this.

[JIMBOBLY]

you will get a little bit of a rush of air,but sometimes the breather pipe can block up,maybe ev en get sucked flat :-k

[stevo123]

i get a substantial rush of air when i open. where is the breather located

[tack43]

There should be a vent in the cap to equalise the pressure otherwise the vacuum will crush the tank. Try a new cap!

Rich

[stevo123]

Many thanks for reply, will get it sorted asap

[Range Rover Blues]

There should be a vent in the cap to equalise the pressure otherwise the vacuum will crush the tank. Try a new cap!

Rich

Whoa, steady on.  From 1989 onwards the nfuel tank vents through a scrubber on the indside of the rear quarter, it should vent under pressure and breath back under veyr slight vacuum.
On later models (catalyst so around '91) the tank vents through a charcoal scrubber in the inner wing behind the battery, it's a round black thing connected to the inlet plenum and the fuel tank, it also has a 3rd pipe connection with nothing on it.  This scrubs the HC out of the tank "breath" and then is cleaned by a purge via engine vacuum, there is an electric valve on the scrubber.

If you have the scrubber you need to check all the pipes are in the right place and not blocked, then check that the valve works asit should otherwise the engine could be sucking at the tank.