Hi,
My knowledge of cars is Zero so probably about the same as most ford mechanics.My Mondeo 2005 Tdi was very sluggish so I went on a few forums looked at a few diagrams and took the plastic manifold cover off, it was full of black soot cleaned it and the car ran better but not great.
I went to Ford and picked up a fuel filter and the mechanic (spotty little lad) said just unclip the old one and place the new one on Hmmmmmmmm Ok I said.
I got home and took the old filter off and replaced it with the nice EMPTY new one and the car started then stopped and wouldn't start. I called Ford to be told it should have been done by a mechanic and the fuel filter should have been filled first and I needed to call a breakdown/recovery or get a mobile mechanic to sort it but it is a big job,I told him great and slammed the phone down.
I decided to turn the ignition to on then pump the gas for about five seconds then turn ignition off, I did this about 15 times then I unclipped the 3 connectors off the fuel pump and sucked the middle nozzel (fuel out) for a few seconds and I got a wonderful taste of diesel.....
I then connected the 3 connectors back on to the pump and pumped the gas peddle for a few seconds and turn the engine....started straight away and now drives like a dream.
Whatever you get told by a Ford mechanic double check because they could be wrong and I hope my information helps if you need to change your fuel filter.
Cheers
Nick