!.6 Hdi fuel filter

[discv]

My fuel filter (1901 95) has a fuel in, a fuel out, and a drain.
There is a large plug at the top with a + shaped inset. It turns round and around but goes no where. I think it may be a vent.
There appears to be no drain screw.

So, to my muppet question, what stops the fuel draining straight out

[MikeT]

I think(?) you'll find it's not a drain but a closed moulding for a water-in-fuel sensor, something my car doesn't have and presumably neither does yours?

[RichardW]

This one?

That is a drain / vent screw - if you unscrew it a couple of turns then pull it up, it will open the drain at the bottom of the filter, and you can then pump some fuel through to clear any water in the bottom of the filter. It's got an O ring on it, so it's tight to pull up. There is a drain pipe underneath that exits somewhere under the car!!

[discv]

Many thanks for the replies. The drain moulding is functional- fuel runs out! it can be seen in RW's photo, bottom left around 5 mm.
But my filter ( marked up PSA) has a different style of vent?

I stated that it just goes round- I wonder if it needs a push downwards to engage.

[MikeT]

There is a drain pipe underneath that exits somewhere under the car!!

Oh yeah, I remember mine now!

[discv]

And the answer was- Haynes totally confused me by referring to the screw on the top of the housing as a vent.
It is in fact drain off open/ shut valve. And it has a very fine thread which gives the impression that nothing is happening.