Heater matrix. Oh no!

peteev · Post by **peteev** » 12 Apr 2005, 23:41

I left the 1995 1.9TD Xantia whilst I went off on holiday. On returning to the car there was a musty smell and some bright blue globules of water running down the heater outlets onto the carpets but worst of all the clouds of moisture deposited all over the windscreen when I was trying to de-mist. A case for some serious Andyspares Forum study!
Rather than just by-pass the heater I decided to ‘bite the bullet’ and replace the matrix. Now having completed the replacement I can confirm it is not a job to undertake lightly, as most of the previous postings stressed.
It is not technically difficult but just seems to go on and on, there is so much dismantling that at times you wonder if the car will ever get back on the road again. I followed the Haynes manual to the letter and also the replacement heater’s manufacture’s (Valeo’s) recommendations on flushing after fitting the new matrix, but additionally:–
1. Before starting have the following:- New heater matrix, 2 heater matrix connector O-rings, Instrument panel lamps (1.2W RW286), Heater panel lamps (1.2W PCB), Thermostat, Thermostat sealing ring, Antifreeze. Hose clips (4 x 30mm) and replacements for all the hoses removed for flushing (probably 4 x 45mm hose clips) Flushing compound (Wynn’s or similar), Cooling system sealing compound (Wynn’s or similar)(these last 2 are recommended to be used by Valeo the heater matrix manufacturer). Might as well fit a new pressure cap as well to finish the job.
2. Take lots of pictures and make sketches on dismantling it could be invaluable later when wondering which route a cable takes etc.
3. I found that the steering wheel was firmly stuck onto the splines and had to spend some time on making up a puller to remove the wheel. Afterwards used Copperease to make sure it does not ‘stick’ again.
4. I found it also necessary to drop the red bonnet release lever (remove the 10mm bolt) to enable the facia to pull clear without fouling.
5. As others have said there is no need to remove the trim panels from the pillars (Chapter 12, section 27, No 29), the facia will come clear by just levering the carpet down a bit.
6. The windscreen wipers were stuck onto the splines. I needed a small puller, a motorcycle one worked well. On re-assembly use Copperease on the splines.
7. Again others have mentioned that there is another heater assembly retaining nut that needs to be removed but is not really clear in the manual (Chapter 3,section10, No27), It is mentioned but it doesn’t say where it is. Remove the top of the air cleaner and its element, then there is adequate access then to this retaining nut on the bulkhead.
8. The turbo diesel’s additional manifold and plastic pipe work does not give enough room to access the matrix connector. It is necessary to remove the 2 long large black plastic ducting pipes that run across the centre of the engine (parallel with the axis of the car).
9. When these are removed then the black plastic pipe that runs parallel with the turbo manifold also needs to be raised on the o/s by disconnecting the hose clip and tying up the r/h (n/s) side, thereby gaining more access to the matrix connector. Even so there is still not much room but with some patience it can be done. (I did not find it necessary to remove the cam cover (Haynes manual chapter3,section 10, No 23).
10. Now we come to the worst part of all which is disconnecting the plastic right-angled double-piped matrix connector. Other postings have recommended doing this job first whilst the engine is still warm. The retaining clip on my car was the ‘later’ one which is metal with a right-angled bend visible at the end. This clip must be ‘released’ before the connector can be removed. This is done by pushing the bent metal bit to the right (n/s) as far as it will go. The retaining end that is holding the pipes together will probably be jammed in position so that at the same time you will need to insert a small screwdriver to the right (n/s) of the metal clip push it in as far as it will go between the clip and the plastic then move the screwdriver to the r/h side to actually release the clip. Now pull on the bulkhead connector and wiggle hard hoping it comes away without any breakage.
11. OK so it didn’t work! Welcome to the club. The clip information is correct the damned thing is just stuck plastic to plastic. So next step: – The matrix will need to be by-passed to flush the system later on, therefore cut both the hoses going to the angled bulkhead connector at the straightest sections that you can see but reasonably close to the connector. Then fit a bypass tube with hose clips to the 2 stubs of tube going into the matrix. I found that using a short length of 15mm copper pipe and sweating 2 x 90 degree end-feed elbows onto it at a slight angle worked fine.
12. It will have been noticed there is a bleed valve on the twin bulkhead connector so undo the cap and put not more than 20 psi pressure from an airline or pump onto the bleed valve connector and the matrix should then part easily from the bulkhead. Make sure the metal clip is released then give the bulkhead connector a good wiggle.
13. If there was a severe leak on the heater matrix then before applying pressure it would be better to remove the 2 x 7mm bolts securing the plastic matrix twin pipe input and output assembly to the actual matrix (this is inside the car) (see illustration chapter 3,section10, illus 10.28c). Remove the old matrix after unclipping the 4 plastic clips and pulling upwards. Make up a blanking plate with a rubber gasket seal and using two longer 7mm bolts bolt the plate onto the twin pipes going through the bulkhead. Apply air pressure as described above.
14. After removing the heater matrix carefully clean out the muck from the bottom of the heater assembly unit left by the old leaking matrix. Drop the new matrix into the heater assembly unit.
15. Now moving onto the engine bulkhead side it is important to make sure the special moulded rubber seal fits snugly onto the bulkhead otherwise the metal securing clip will not clip in properly. Whilst bolting on the metal retaining plate (see illustration chapter 3, section 10, illus 10.26b) pass a longish plastic cable clip behind it. This is ‘belt and braces stuff’ just in case the metal retaining clip fails or is not doing its stuff properly.
16. Place new O-rings inside the new matrix sockets, I used a silicon spray (cheap stuff used by builders to spray onto rain guttering connectors) to facilitate easy installation.
17. Clean and examine the plastic bulkhead connector carefully especially the metal clip, make sure the ‘clipping’ angled end is resting close to the r/h pipe (may have to use some judicial bending). Spray the bulkhead connector spigots with silicone and very carefully insert the spigots evenly into the matrix connector so that the O-rings are ‘taken up’ and seal properly. It will be necessary to use a piece of hardwood to press the connector home, a definite click will be heard when the metal retaining clip finally clicks home. Loop the plastic cable clip inserted earlier behind the metal plate around the connector, secure and pull tight.
18. A much better and much faster alternative:– I found that my Valeo replacement heater matrix was identical to the old one removed. The twin pipe assembly can be removed from the actual matrix by undoing the 2x 7mm bolts on the flange and separating the twin pipes from the matrix. In other words it is not necessary to separate the right-angled plastic connector on the engine side of the bulkhead, this connector is best left well alone. It is still necessary though to cut the supply and return hoses to this connector so that the system can be flushed through as recommended by Valeo.
19. If you decide to go this route it will save a lot of hassle and time. Do not touch the bulkhead connector (Once you start to fiddle here then you cannot be sure that the retaining clip will still be holding). So after removing the facia and releasing the heater assembly and draining the system (We are up to Haynes Ch3, sect 10, No 22). Move inside the car and undo the 2 x 7mm bolts on the heater matrix and gently ease the 2 flanges apart, this then releases the matrix itself and by pulling the heater assembly away from the bulkhead the matrix can be pulled out from the heater assembly after releasing the 4 plastic clips, make sure the old O-rings are removed from the bulkhead connector spigots.
20. Clean out all the muck at the bottom of the heater unit assembly left by the old leaking matrix. Then undo the flange from the new matrix and carefully retain the two O-rings. Spray the new matrix pipe sockets with silicone. Drop the new matrix into the heater assembly insert the new O-rings into the matrix sockets and carefully mate the new matrix to the old flange and tighten the 2x 7mm bolts evenly. Done.
21. Finally after finishing the complete re-assembly, whichever route you take with the installation follow Valeo’s recommendations on flushing. It is necessary to bypass the new matrix to do this (see 11 above). The thermostat needs to be removed whilst flushing, so might as well replace it with a new one and a new seal on re-assembly. To re-connect the heater hoses I found that again 15mm copper pipe worked ok. (Use a straight end feed connector with 2 short pieces of 15mm pipe sweated into the connector and nip up 15mm olives at the ends, the whole assembly should be about 55mm long). Secure with 25mm hose clips. Continue re-assemble as per Haynes.
22. Before fitting the heater panel into the facia test the 2 illumination bulbs and replace if necessary. Similarly before replacing the instrument panel test all the illumination bulbs and replace all the faulty ones.
I now have a fully functional car and heater so thanks to all the other postings on this subject that gave me confidence to tackle the job and especially to Richard Gallagher who was kind enough to post replies to my calls for help.

ghostrider · Post by **ghostrider** » 13 Apr 2005, 00:02

Nice one Peteev, with this article and Richards posts, I will be able to do it, (cant be worse than the CX can it? [:D] [:D] ) but whether it's worth the time or effort I very much doubt
Pete
________
BROUGHAM

jeremy · Post by **jeremy** » 13 Apr 2005, 00:35

I'm interested that valeo recommend using Wynns sealer in the system. I fitted w ner valeo rad to my TD BX last year and there were no instrcutions at all with it.
My only concern is the wisdom of introducing a 3rd chemically quite active metal (Copper) into the system and hope it won't cause electrochemical corrosion.
I remember hours of good fun doing the job on my Renault 21 only to have to have the dash out a couple of years later to overhaul the wiring after the fan siezed and set fire to the loom! (Fused 75 amp!)
jeremy

Richard Gallagher · Post by **Richard Gallagher** » 13 Apr 2005, 00:37

Well done, a good guide for the use of others, I'm pleased to have been of help.

peteev · Post by **peteev** » 13 Apr 2005, 01:00

Jeremy, The bulletin (TSB No EC 003) on flushing and adding a 'cooling system condioner'after fitting a new heater matrix came with my new matrix from GSF. As to the introduction of a further metal into the cooling system and the risk of electrolytic corrosion, radiators were tradionally made of copper, are they still? Certainly the engine block drain is sealed with a copper washer. Anyway I am sure you are right about adding the 'conditioner' I thought long and hard about this before adding it but then if the manufacturer recommends it ??

jeremy · Post by **jeremy** » 13 Apr 2005, 01:17

The radiator core and the heater matrix are made from aluminium alloy. The washer shouldn't have any water circulation from it. Aluminium is a strange substance and can behave as an acid sometimes if I remember corectly.
the 'conditioner' point is interesting as jaguar used to use barrs from new - wasn't sure if it was to stop some of those lovely polished castings from being porous but I put some in when the heater part of the aircon on my Series !!! XJ6 sprung a leak and it looked easier to chop the car in half and weld it up again.
jeremy

zzf00l · Post by **zzf00l** » 13 Apr 2005, 01:29

Blimey!! I shan't be doing mine that's for sure, but well done for taking the time to give such an informative blow by blow for those who feel capable of tackling the job.
Surely as a starting member you should be awarded 1 star for effort at least lol

alan s · Post by **alan s** » 13 Apr 2005, 04:37

So that all this work isn't lost, I've done a copy and paste and it now also resides on the common faults and fixes board for future reference.
It appears that one of the most scarey jobs on most cars in particular a Xantia is this matrix job which as pointed out is more a time consuming job than a technical one. I posted about the fans a while back and that one takes some understanding too but in this case I suggest everybody with any of these cars keeps a good close eye on the coolant as regards regularity of changes and quality of what goes in it to help guard against the possibility of this occurring.
Alan S[;)]

JohnW · Post by **JohnW** » 13 Apr 2005, 18:47

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by peteev</i>

I left the 1995 1.9TD Xantia whilst I went off on holiday. On returning to the car there was a musty smell and some bright blue globules of water running down the heater outlets onto the carpets but worst of all the clouds of moisture deposited all over the windscreen when I was trying to de-mist. A case for some serious Andyspares Forum study!
I now have a fully functional car and heater so thanks to all the other postings on this subject that gave me confidence to tackle the job and especially to Richard Gallagher who was kind enough to post replies to my calls for help.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
I can only say two things.
1. Well done and many, many thanks for taking the trouble to post such a valuable and thorough description.
2. Aaargghhh!
JohnW (owner of non-leaky Xantia and twice replaced 306 matrix car)

peteev · Post by **peteev** » 13 Apr 2005, 23:36

Thanks for all the kind words guys, the one thing I didn’t mention was that by the time I finished including all the flushing procedures I was into my 4th day! This job needs plenty of time and a cool head. As to reconnecting the hoses inside the bulkhead after flushing, the 15mm copper was my own way of re-connecting, it is probable that a high temperature tolerant plastic or some aluminium tubing would maybe be better it is your choice I only recorded my experiences and hopefully some useful tips. Good luck to anyone else about to attack this cursed job! Peter.