If your XUD filter housing bottom seal goes on friday night.

falling-out-with-my-car · Post by **falling-out-with-my-car** » 07 Jul 2011, 09:55

I learnt this one from the veggy site but thought it might be interesting to anyone who seems to be as lucky as I am when the xantia diesel produces a fault i.e. late Friday Night, easter friday, Christmas eve, I think you get my drift, Not enough time before the weekend/hols to get any parts.

if you have a citroen Xantia with an XUD diesel engine you probably have the black plastic cylindrical fuel filter housing, this has a teflon seal at the base, if this should spring a leak try removing the housing by undoing the four allen key bolts on the lid pulling up the filter and placing it in a container allowing the fuel to drain out.

if you have a kitchen towel roll half used it would be a great way to soak up the fuel inside the filter housing at this point if not find a nice large piece of rag.
undo the 13mm bolt in the centre of the housing base and carefully lift the housing from its mounting, put the bolt back in the mounting so it doesnt get lost. dont loose the seal from the bottom of the housing we are going to use this again even if it has shrunk or cracked a little bit. you will need to disconnect the fuel line to the rear of the housing.

right wash the base of the housing in petrol, and clean the mounting on the engine with brake cleaner and a soft bathroom scouring pad, the brake cleaner will soften the plastic scourer anyway so dont worry about scratching the surface.

Now from any good independant plumbers suppliers purchase a tube of Fernox LSX silicone about £2.50 a tube. half fill the outer groove that the seal fits in on the bottom of the filter housing with silicone and gently stick the seal to this so it is protruding above the groove by about half of its thickness and allow to dry over night.
ensuring the mounting is clean and dry apply a smear of LSX silicone to the outer edge of the seal making quite sure that no silicone can contaminate the inner grooves on the bottom of the filter housing. now put the fuel lines back on the filter with a little smear of LSX silicone to get an air tight seal then put the filter housing back on its mounting and bolt it down at this point some sillicone will ooze from the sides this can be smeared with a wet finger to tidy it up. leave to dry for at least 2 hours for a perfect seal.

I repaired my oem filter housing like this five months ago when citroen told me they couldnt sell me the seal and wanted to flog me the whole filter housing at an extorsornate price. peugeot sell seals but it never happens on a monday does it? always on friday or flippin cristmas eve when there is no time to buy parts, yet there is a good chance a plumbers merchant will have a tube of LSX silicone in stock if not a similar product
and in less than the time it takes to order a new seal the job can be done with pretty good results.

if your suffering from air leaks in the fuel system it could be that the lid of the filter has been over tightened at some point smear some LSX silicone around the edges of the lid after it is bolted down and this can cure a leaky lid the 2 hour setting time makes it a quick job.

regards Nigel.

jgra1 · Post by **jgra1** » 07 Jul 2011, 12:55

thanks Nigel, good stuff
John

Old-Guy · Post by **Old-Guy** » 08 Jul 2011, 16:35

Well done Nigel.

On a closely related line: if you break off the fuel outlet spigot from the lid of the same fuel filter housing on a Saturday afternoon (like what I did!), don't despair. Rush out and buy a pack of Araldite Rapid (I had a pack in 'stock').

Remove the lid and extract broken spigot from 'rubber' fuel pipe. Soak both in clean petrol while you have a cuppa. Dry and wash in a hot and strong solution of washing powder/liquid. Roll up a scrap of thickish (e.g. 1,000 gauge) polythene to act as an internal splint right through the break. Glue the spigot back in place with a generous fillet of Araldite around the break (it's easy once the Araldite starts to go off but you need to be quick. Once the Araldite is the consistency of fresh icing, trim off any excess and leave to set overnight somewhere warm. Reassemble the filter being careful not to get brutal with the spigot.

You'll find that the Araldite tends to become a bit pliable when the engines hot, but this 'bodge' lasted for over a year (and something like 15,000 miles - mostly fast motorway cruising) until I acquired a replacement filter lid.

falling-out-with-my-car · Post by **falling-out-with-my-car** » 08 Jul 2011, 22:42

I made a hole in my clear plastic fuel line from the top of the filter housing to the fuel pump so I stuck aeroldite on it and it is still holding.
good stuff aeroldite and very resistant to waste veg oil.

Actually come to think of it you can probably drain the fuel from the XUD fuel filter housing by openning the water drain screw and drainning the fuel into a jar it will at least save a bit of fuel I suppose.

wotwot · Post by **wotwot** » 13 Jul 2011, 11:26

Hi just did as others have done and replaced the "O" ring at the bottom of the housing.
What is the teflon seal have i missed something,I did have what appeared to be loctite underneath by the screw which just disintigrated.
But dont have a teflon seal anywhere.

falling-out-with-my-car · Post by **falling-out-with-my-car** » 13 Jul 2011, 13:46

I believe that the o-ring is teflon coated to prevent it from degrading or sticking to the heater matrix it sits on as it is heated to very high temperatures.

wotwot · Post by **wotwot** » 13 Jul 2011, 15:33

Maybe mine had been changed already as it was just a rubber O ring.
I would'nt have thought it gets that hot unless the engine is overheating

.
The newer EPDM silicone based gaskets are very resilient to temperature.
Could someone clarify if and why they are made with a teflon cover.