anyone shed some light on this please

just put new tank and new breather pipe into my cabs


now just put a jerry can of fuel in and it decided to chuck it back out

now the two littl evacumn breathers came off the the main filla neck and theres a valve could this cause it if i have them the wrong way round or could it be something else

any ideas please

edidted cus forgot to say its a mk4 turbo