Land Rover Repair: Fueling up, filler nozzle, vent tube

Question
I have a 2001 disco2 4.0 litre v8 when trying to fill the gas tank the gas backs up in the filler neck and shuts off the filler nozzle it does this even when filling slowly by hand i cannot even fill by locking the nozzle i must do this by hand
i have the NAS filler neck this is a really annoying is there a modification that can be done to the filler neck or a replacement neck
any info on this will be greatly appreciated

thanks bruce

Answer
Hi Bruce,

I've heard of this problem before.  It has to be a pressurization problem.  There is an air vent tube that allows air to pass as you are filling your tank.  If this tube is crimped or damaged it could restrict the air flow and thus cause this problem with every fill-up.

One owner who had this problem, while under warranty, was so fustrated after at least 4 service calls that he insisted on having his fuel tank replaced.  Seems to have solved the problem for him.  

In your case, you may have to replace the filler neck assembly, perhaps the fault lies near the top and not within the tank.  Otherwise, the tank will have to be replaced.

I wondered if the air vent tube could be tested...but since it deals with gas, I'd have an expert pressure test this for blockage.

Best of luck,

JohnMc

NB: I wonder if a very long pvc tube could be used to replace the OEM air vent?  You'd have to uncollar the filler neck from under your Disco and feed the 'new' air vent tube down into the tank.