Xantia heater matrix renewal

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davethewheel
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Post by davethewheel »

i was very surprised when i removed my leaking xantia matrix to find the it wasn't leaking as a result of a rotten core like i've normally found on other cars it was leaking at the plastic top were the two halves are put together looks like a design fault to me.
i would never right a car of for a heater matrix failure, it's not a particularly difficult job or expensive if you are doing it yourself it just takes ages mine took me 10hrs and id never done one before on a xantia.
C.J.
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Post by C.J. »

citrojim wrote:
As regards a preventative measure, yes there is. Put a bottle of Forte Stop Leak in the system right now. My old matrix is living proof that it works rather well. It stopped up my leak completely and the residue of it can be seen in the picture of my old matrix. It did not stop the smell simply as the damage had already been done and the heater plenum was full of crystallysed antifreeze residue which would smell when it got hot.

I once saw that Valeo (the maker of the matrix) recommended the use of Forte with a replacement matrix as a preventitive measure. That was for a Pug 205 matrix that is very similar and fail just as regularly.
Isn't this 'Forte Stop' not likely to bung the whole matrix up though?
What exactly does it consist of?

I really don't see me ever changing a matrix tbh. My patience threshold for that type of job would be approx 15 minutes, a gashed hand, launched tools, and much swearing. :roll:
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Post by CitroJim »

C.J. wrote: Isn't this 'Forte Stop' not likely to bung the whole matrix up though?
What exactly does it consist of?
No, not at all. It looks like thin, pale blue milk unlike K seal or Barrs Leaks which is considerably thicker and has quite large metallic lumps and flakes in it. I believe Forte is perfectly safe to leave in the cooling system on a permanant basis. Legend has it that the active ingredient is vegetable in origin, possibly bamboo fibres. In fact, when you pour it from the bottle it seems impossible it can do the job it is so thin and insubstantial in appearance.

I've had it in my cooling system for a good few months with no adverse effects and it's still in there.

It works on broadly the same principle as platelets in blood.

It's relatively expensive and only available trade normally but there are sources of it via eBay.
Jim

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Post by andmcit »

Some pictures showing the heater box removal on the scrapper:

where it hides behind the dash and wiring loom:
Image

matrix collar bolts undone - lugs showing grip on the top of the matrix:
Image

O rings:
Image

grubby picture showing stud that goes through bulkhead securing the heater box:
Image

one of the dash securing points high on the scuttle with daylight circle hole through bulkhead:
Image

heater box fastener from engine bay side:
Image

another grubby picture showing AC mounting drawn through into interior of the footwell:
Image

the damned matrix! This one looked a bit wet inside the heater box and had traces of staining:
Image


The undo of the AC drain tap was doable but all done by braille from above
as I couldn't reach anything from below. I'd hate to try and patch it all back
together again... :shock: :?

Andrew
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Post by andmcit »

john alexander wrote:Hi andrew , I think thats the one , are the pipes screwed on with large nuts . the sanden version has a pad fitting with one bolt in the centre . did the a/c work on the car? regards John.
Yep, two BIIIGGG nuts fastening pipes to the pump body.

There was some gas in the system though not under a big pressure.
As it happens, I was fretting about venting the pipes properly and stop
the gas unenvironmentally escaping but inadvertently managed to damage
a feed pipe into the front heat exchanger radiator whilst removing the
whole lot off the front end and having to coax the fan panel out - can't
believe how soft the metal is. Well worth the fact finding exercise before
I ruin my Activa... :roll:

Andrew
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Post by CitroJim »

They're some seriously valuable pictures Andrew :D

You've answered a question perhaps in that it is possible to disconnect the matrix at the joint on the matrix rather than the much more difficult and risky water connector in the engine bay.

How easy was it to do it that way compared to the traditional method?
Jim

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Post by andmcit »

Hi Jim.

The joint inside the car onto the matrix bulkhead comes apart easily
enough although it obviously needs the main heater box to have
slack movement, permitted by drawing it off the bulkhead.

I really needn't have undone the outside (engine bay) side at all as
the fitting doesn't need any movement and was only later tried where
I tested a new approach to undoing the outer fitting using a claw head
hammer head which worked a treat allowing a decent leverage but
still permittting space to get a hand onto the spring and main pipework
of the fitting.

I did try running the engine up to temperature first as you suggested.

Andrew
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Post by davethewheel »

citrojim wrote:They're some seriously valuable pictures Andrew :D

You've answered a question perhaps in that it is possible to disconnect the matrix at the joint on the matrix rather than the much more difficult and risky water connector in the engine bay.

How easy was it to do it that way compared to the traditional method?
thats were mine was leaking from at the joint it the plastic was distorted around that area i don't think i would risk splitting it apart in case it leaked again.
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Post by andmcit »

There's no real strain or distortion on the joint and it's stepped with quite a
significant overlap and ultimately has the o rings to seal the joint so I can't
see how it could fail on it's own without a bit of additional help (provocation!).

The heater box undoes from the bulkhead and you can slide it sideways to
the left and back away from the joint and create enough clearance to allow
the matrix to lift upwards and out past the overhang of the main bulkhead.

I can't see a matrix going here very easily and have seen load fail on the
band strapping that runs around the end caps holding them onto the main
vanes of the matrix itself.

Andrew
davethewheel
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Post by davethewheel »

maybe mine was a one off i don't know but it was leaking from around the joint were the two o-rings are it was all crusty and stained in that area the rest of the matrix looked fine thats why i was so disappointed to have done all that work only to find it had failed on 2 simple o-rings.
andmcit
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Post by andmcit »

davethewheel wrote:...thats why i was so disappointed to have done all
that work only to find it had failed on 2 simple o-rings.
Know exactly what you mean. The failure is a weird one as I've seen every
matrix I've changed fail in the main core; this is on Cx, Xm and now Xantia.
The answer is to run a 2CV or a GS! :lol: :wink:

Andrew
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Post by john alexander »

Hi andrew I,m on holiday for 2 weeks any chance you could hang on to the a/c pump till I get back. regards john.
andmcit
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Post by andmcit »

No problem at all John - it's not going anywhere - well, that's not true;
it's going everywhere! :D At the moment it's still in the boot of my Xm all
wrapped up, but I'll take it out and get some pics of it for you.

There's no hurry! Have a good holiday!!!!

All the best,
Andrew
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Post by Adrianpaul »

Hi Andrew,

I was referred to this link for assistance in the same task which I'm pleased to say was a success thanks greatly to your notes and pix.

Greatly appreciated your recommendations. Labeling all the wires was absolutely essential and the more pix the better (I didn't take enough but managed).

PS I didn't have to remove the steering wheel, I just undid the bolts and let the wheel and column drop allowing the dash to go over the top.

All up it took me 12 hours with a friend working together (without rushing) Only one or two minor mishaps; two instrument connections were not reconnected fully, resulting in having to undo the cover panels a second time.

So thanks again - My Xantia will live on :D
Cheers
Adrian

1974 DS23ie
1971 2CV
2000 Xantia V6
citronut
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Post by citronut »

maybe some one will have to find a quike way to do this job like the one for a CX,

who'z going to cut the top out of there dash and cross member first, oh and it might also need the screen removed,

TEA HE

regards malcolm
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