Air Bubbles from diesel fuel filter. Xantia 1998 Mk2

falling-out-with-my-car · Post by **falling-out-with-my-car** » 12 Jul 2010, 13:20

Hi,

I have chased a fault of air in my diesel in my citroen xantia Mk2 1998 (edited from 89 appolagies for the mistake).

I have installed some clear fuel line with proper fuel clips and can find no air from the squeezy bulb or tank side of the fuel filter.

every time I rasie the throttle speed I get large air bubbles running to the pump fuel line.

I have seen something about replacing the seals at the bottom of the fuel filter housing, could some one please point me to this as I think its going be a summer job (whats left of it) better that than waiting till winter and the problem getting worse.

a couple of questions if you please?

1) is it a pain in the neck to do these seals or nice and easy?
2)would it be easier to just buy /obtain a different filter system with screw on filters as I have a heat exxchanger fitted to heat my fuel system.

3) which is the easiest most reliable option for running on Veg please as I have heard I could be back in the same position pretty soon running on veg oil as it eats the seals.

thank you in advance Nigel.

Xaccers · Post by **Xaccers** » 12 Jul 2010, 22:03

I've had the same thing Nigel, although in my case replacing the short thicker pipe from the filter housing to where it steps down on the way to the pump with new clear piping and using decent jubilee clips so they can be really tightened.

Another place to check is around the lid of the filter housing for veg gum which prevents it closing on the filter seal properly.

The other important thing is the type of filter used, I expect you're using the Halfraud's type with the metal bottom, exposed filter sides and single hole in the middle of the metal top (the top has a rubber seal around it which can easily come off so another thing to check).
This type of filter is the one to go for. The one to avoid is the plastic cylindrical one with the open bottom and multiple holes on the top. The glue which holds the filter in place breaks down, and the filter paper swells making it difficult to remove the filter!

Moving down the filter housing, there's the thermostat on the pump side of it (white dial looking thing).
There's been threads on that recently about replacing the seals there, or using sealant with varying rates of success.

falling-out-with-my-car · Post by **falling-out-with-my-car** » 13 Jul 2010, 13:15

Xac,
thanks for the reply,

I have changed the line to the pump with new clear 8mm line clamped on with proper fuel hose clamps not jubilee clips. I pressure tested this line in a bowl of water before installing it into the xantia, I wanted to be absolutely sure there wasnt any leaks.

as I said above the air is definately created within the fuel filter somewhere.
I change the filter every 3, 000 miles or three months when I do an oil and filter change so it is not being left a long time without service.

I have to admit I wasnt to happy with the quality of the large rubber seal on the last one I purchased, in fact it fell of and I had to put it back on again.

the filter inside the housing itself is the metal one I will check the lid as soon as him upstairs stops throwing water at us..lol.

some people seem to think that its a nightmare to fix these air leaks on an xud filter housing is this true?

cheers Nigel.

spider · Post by **spider** » 13 Jul 2010, 13:41

Out of the filter designs on I.D engines, the top-hat one (the one you have) is the best one for lack of air ingress to be honest in my opinion anyway, compared to the other earlier methods they had.

It's either (as above) the seal on the lid / the filter itself or possibly the stat adjuster (the white screw on the side) , assuming your pipework is OK (as you say its 'starting' in the filter)

falling-out-with-my-car · Post by **falling-out-with-my-car** » 13 Jul 2010, 13:47

Andy,

as you say the (white screw on the side could be the cause)

do I just unscrew this then?

is there an o-ring behind it?

I am having a lot of trouble actually finding any type of description of how to take the filter housing appart to service it. looking end on at the stat it is white and + shaped or is mine broken? I thinkl I shall have to go to citroen and get an exploded diagram and order some seals.

thanks Nigel.

spider · Post by **spider** » 13 Jul 2010, 13:50

I've never taken out out, as I don't own anything with that type fitted.

I'd advise against playing with it too much though. It controls how much heating the fuel gets mainly. You could temporarily apply a little grease (I think that would be ok but I am not sure) to it to see if that helps (as the grease will provide a temporary seal) , caution: untested at your own risk etc.

Give me 5 minutes I'll see if I can furnish you with a diagram

spider · Post by **spider** » 13 Jul 2010, 13:52

Actually I've just seen you put 1989, what sort of filter do you have ? I was not aware the top-hat filter started until late 91 / 92 ?

Does it sit on top of the thermostat housing and is black plastic with four allen headed screws in its lid ?

I'm assuming 89 is a typo

falling-out-with-my-car · Post by **falling-out-with-my-car** » 13 Jul 2010, 13:56

Andy,

yes sorry 1998 was my intentional description. yes it is black and sits on top of the thermostat housing and has for hex key bolts on top. I wouldn't worry to much about the heat as I have a heat exchanger fitted after the filter anyway, this is why I have considered replacing the whole filter housing with something like a BX filter housing but its difficult to imagine where the hell you'd mount such a filter housing in the engine bay of an xantia turbo there is not a lot of room.

cheers Nigel.

spider · Post by **spider** » 13 Jul 2010, 14:01

This is a 406 one, (XUD9) although its the same:

Interesting to note, there is no explanation for the heating control (item 9 and 12)

6 is the 'water in fuel' sensor, you may have it or not.

5 is the drain plug when you want to drain the filter to change it

8 is the rubber seal under the housing (mainly to stop coolant leaks)

70 is the bolt (I 'think' there's a seal with it) holding it to the thermostat housing itself. Note: coolant will pour out if you remove this.

I don't have Citroen diagrams, but as I say its the same as the 406 one as far as I am aware.

I hope that's a bit of help anyway.

falling-out-with-my-car · Post by **falling-out-with-my-car** » 13 Jul 2010, 14:08

Andy,

Thanks for that thats the closest anyone has been to providing a decent diagram anyway, much appreciated.

as you say 6 is not used on mine and if 70 realeases coolant and there is no coolant in the fuel then this seal is probably ok,

I think I shall draw my attention to the thermostat on the side of the housing and replace the filter itself, I have never over tightned the lid as I though it may warp under extreem engine temperatures.

thanks I can print that off and use it as a guide, brilliant, thats what these forums were designed for.

with thanks, Nigel.

spider · Post by **spider** » 13 Jul 2010, 15:59

You're welcome.

70 is the bolt inside the filter housing, holding it to the top of the thermostat housing. The seal between them is 8.

Its very very unlikely to ever get coolant in fuel, if seal 8 failed (rare in my experience to be honest) it would have a small coolant leak around the housing, it would not actually effect the fuel system as such.

The diagrams make it easy to follow anyway.

falling-out-with-my-car · Post by **falling-out-with-my-car** » 13 Jul 2010, 16:49

Andy,

I have just been down to the Kettering citroen parts department.

it is not possible to buy a seals kit any longer for this type of filter housing,

which explains why they always go first from the scrappy.

it is £67+vat for a new one, now being as I run veg and it likes to eat the rubber seals I think I am going to retro-fit a metal filter housing and the only place I can forsee it going is next to my LHM tank on my xantia as everywhere else is clogged up with citroen kit, air-con, air filter,and ecu and its various black boxes of relays.

I shall have to hope I can find something a bit more solid state and hopefully cheaper to maintain.

sorry to kick you in the teeth with this one I do apreciate your efforts But I had no way of knowing that citroen were to stop selling seals kits.

best wishes Nigel.

spider · Post by **spider** » 13 Jul 2010, 17:03

Try a Peugeot dealer, its the same thing.

That design of filter housing was used up till about 98 / 99 (until the DW8 replaced the N/A XUD)

Should still be available really. Worth a phone call at least.

I don't have that design on my 205 it will not fit (its a long story why) I got something off ebay and made my own fuel heater. Pics available if you want...

Post by **myglaren** » 13 Jul 2010, 17:09

Have you tried GSF or EuroCarParts for replacement filters and seal kits Nigel?

Wouldn't swear to it but it looks the same as the one on my son's 306 D-Turbo.

falling-out-with-my-car · Post by **falling-out-with-my-car** » 13 Jul 2010, 17:33

steve,

the picy above probably is of a Peugeot and it is quite different to my xantia filter housing in lots of ways it doesnt have quite so many componants as that does but it gives a good general idea of what I need to replace.

the trouble is I have been running 1 micron filterted Waste veg oil for about 18 months if I repair this housing and it fails again 18 months down the line I shall be back at square 1 again, so I am looking at replacing or by-passing the orriginal filter housing with a lucas/cav sandwich filter at the moment priced at less than £20 and all seals are easily available and cheap as chips excuse the pun.

regards Nigel.