Last week I had a major derv leak on my van, derv was pissing out of the filter, lucky we where in carlingford marinea and Darren let me use his workshop to get it fixed ,I have now discovered that this is a common problem my van sat most of the winter not being used it was serviced before I put it of the road ,the proper way to change the filter is to take the whole filter casing from the van ,and this is the important bit there is a special tool which you put the complete filercase into put the top on and remove it with a socket the seal must go into the top of the filter top put back on and torced till to lines Match up on the filter bace and the top if anyone else has come across this it would be good to find out ,apparently if the filter top is not taken of with the correct tool it can damage the threads or warp the filter head fiat know of the problem my van is 07 so I don’t know if fiat have renewed or changed the filters in newer vans,it has just cost me £135.00 for a new filter housing and the proper tool to change it on its next service,I’ve also bought an in-line filter from halfords which I intend to keep in the van in case it happens again then I can put the inline filter on bypassing the van filter to get us home