Filler cap reassembly

[Roy748]

Hello all
Can anyone give me a diagram of how the filler cap is assembled. Each time I fill up my petrol bongo I always get a hiss upon removing the filler cap. The van appears to run ok, but if i have an ssue with fuel starvation of a small extent it would be good to cure it.
I have taken the cap apart and all seems ok, but want to check my reassemble was correct.
Thanks in advance

[g8dhe]

That's pretty normal as the tanks can be different from ambient pressure - its the amount that's critical!
This is the V6 cap;

[Roy748]

Thanks G8dhe
That's how I reassembled it. I get quite a noticable hiss upon removal, yet I always read their should be no hiss upon removal.

[g8dhe]

No I think its confusion with the diesel version, in a diesel the hiss is caused by vacuum and should be fairly small hence the spring araagment is a lot different. The internal vacuum pulls the outlet cap down against the spring, to ensure that the tank doesn't collapse and that fumes are not emitted;


Whilst in a petrol its caused by excess pressure of the returned fuel & vapor to the tank and also works in the other direction to prevent tank collapse

[Roy748]

Thanks for the clarity, this will ease my mind...