Heater matrix firewall union - plastic unit broken

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JamesQB
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Heater matrix firewall union - plastic unit broken

Post by JamesQB »

Hi,

My parents' Xantia 1.8i is losing coolant at a fast rate (boiling dry in one trip out) but they can't seem to find where it's coming from. Anyway, my brother's looked into it and thinks there are signs of leakage around where the two heater matrix pipes join onto a coupler at the bulkhead under the bonnet.

I'm trying to find the part number for the O ring seals that go on the end of these pipes but can't find them. I went to service.citroen and found it only displayed large parts like the pipes themselves, not small things like seals, etc. Could anyone help please?

Thanks, James
Last edited by JamesQB on 13 Nov 2008, 18:37, edited 1 time in total.
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Post by DickieG »

The part number is 6464 V1, they are number 11 in the diagram.
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Post by JamesQB »

Thanks for that. Incidentally, are you referring to a diagram which should be available to even me on service.citroen? If so, maybe you could tell me how I get to such diagrams because I couldn't get to anything more constructive than basic block diagrams which, for the heating system, only returned 3 parts - all hoses.

Thanks.
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Post by citronut »

click on the main item which relates to the part you are looking for, then click on the more specific part on the exloded diagram of say the hoses or maybe the heater matrix, this will give you a panle at the right hand side which has descrption and part No. for every part on the exploded diagram

hope this works

regards malcolm
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Post by wrinklet1 »

Before you start stripping everything down to find your leak. try this :-

Get a tyre pump and connect it to the tyre valve that on the hose that is near the cam belt cover. This is the one for bleeding the system. with the engine off pump some air into the system to pressurise it and then look for a water leak. I have done this a couple of times but used an electric tyre pump (12volt). I found the leak quickly (on my mk1 xantia td)

Give it a try.

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Post by JamesQB »

Thanks for the help using the service.citroen site, I found the proper parts diagrams.

And thanks for that brilliant idea on pressurising the coolant system using the bleed nipple - I'd never have thought of it. Out of interest and caution, what's the max pressure you used to pressurise the system to?
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Post by addo »

I'm pretty sure the cap relief pressure is 22PSI - that ought to be a guide. I found my last leak simply by squeezing the top radiator hose after patting everything dry and topping up the system.

However, two things about your initial post stand out. Firstly, boiling it dry (I realise this is somewhat vernacular) may well have caused further damage. You'd be surprised how many mishaps go from small to large when preceded by the four-letter-word just... As in "We were just trying to make it back to town." Cross your fingers for the motor, but heat may well have injured the head.

Secondly, the most common firewall junction leak at this point you describe, is failure of the plastic hose barbs. An "irreparable" assembly, I experienced this a fortnight back - posting my results on this forum. There are several modes of repair at varying cost levels.

Regards, Adam.
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Post by JamesQB »

The problem has been found. The plastic assembly at the end of the coolant hoses which plugs into the heater matrix has indeed broken. Citroen has said they only sell the entire hose assembly at a cost of 310 euros...

What a ridiculous amount of money. Unless a scrapyard assembly can be found, the car will be scrap.
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Post by handyman »

James, do not scrap the car as you can scavenge the plastic elbows from another car to repair the cracked elbows. If you cannot find any PM me as I have done this repair on quite a few Xantias, other Citroens and Peugeots and I have plenty of spares. If you can get to East Sussex I can even do the repair.

The elbows can be separated from the hoses and with a replacement elbow assembly and a pair of Jubilee clips you can get the car performing correctly again.

The plastic in the elbows suffers heat fatigue and cavitation which causes them to fail. They become extremely brittle.

Jim, (Citrojim)I'll send you a write up on the procedure for you to post in the archive.

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Post by CitroJim »

handyman wrote: Jim, (Citrojim)I'll send you a write up on the procedure for you to post in the archive.
Handyman, that'll be very much appreciated :D
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Post by JamesQB »

Handyman, thank you very much for your kind offer of help. I've PMed you now.
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