In 300,000 miles of motoring which is a lot of filter changes I have only
once seen any water in the fuel (after a cheap supermarket fill up)
It is possible the drain pipe is blocked, but I only drained mine down this
way the first time I did the job. It takes ages to empty.
I wipe the filter area clean and wrap clean rag around the filter body to
catch any spillage, take out the 4 screws remove the lid and filter element.
At the bottom of the filter housing if there is any water you will see it as
little drops at the bottom. There might be other small pieces of debris. The
drain pipe is carefully sited so that it doesnt actually drain all this out
anyway. If its clean leave the fuel there and pop in the new filter element.
If there is a lot of muck there drain it down and clean out carefully with
lint free cloth or paper. Refit the lid and screws. Remove the rag. It is
important to take care to keep ALL dirt away from the area
I never knew the screws had locking compound on. Mine certainly dont now and
I've never had a problem with leaks.
Note that this is not a bleed screw. All the bleeding is done with the
rubber bulb and hence no mess unlike other engines I have worked on.

My Xantia 1.9td (similar engine) does much the same but without the his
of air. I find the only way to get any flow through the tube is to use
the priming bulb.