WARNING: It worked for me, but I take no responsibility whatever for > whatever mess you might get into. Note that at the time another poster > said Mark IIs were harder and dash did have to come out.>

And once again I point to this link > http://rangerovers.­net/repairdetails/he­ateroring.html> which is for a Rangerover but the O-ring housing and construction is > virtually identical to a 405 - it helps to see the O-ring cover to know > what you are going for.>

I guess it was about an hour to get the matrix out. Half an hour to fit. > And an hour and a half to reassemble. But I'm slow. All while very > uncomfortably laying with the door frame sticking in my ribs - so get a > pillow!>

Here's my post:>

"" Well, the new heater matrix is in and working, and while it is fresh in > my mind I thought I'd set out how I did it (saving Ј444) ... in case > anyone ever needs it.>

Mark 1 1992 405 turbo diesel estate, without air conditioning.> Basically you get the glove box out and everything else is easy.>

1. Remove the soft cowl under the glove box.> 2. Remove the lower side of the central tunnel. It's plastic and pops off > four or five clips.> 3. Remove the lower plastic inner door surround, one screw and then pops > off.> 4. Remove the eight or nine screws inside the glove box cover, and pull > off outer skin.> 5. Tap out the roll pins inside the cover end of the two restraining arms > with a suitably sized drill bit, split pin or drift. The glove box door is > now free. [[Note how the springs go - I didn't and never got them back > right]]> 6. Inside the glove box, with a mirror, find one screw in the centre top > edge and one in the left top edge with heads facing away from you. Remove.> 7. On the left side near the big fascia screw, find a small screw pointing > up. Remove.> 8. On the right side, near the big fascia screw, with a mirror, find a > small screw pointing up, remove.> 9. Well above this, in the mirror, you can just see the last retaining > screw, which I could not reach.> 10. Free the glove box, starting on the left. There is a big cable bundle > tied to the box. Cut tie.> 11. At the top at the back is a clip which holds the edge. Prise edge > free.> 12. The only thing now holding the glove box is the last unreachable screw > noted at 9. I decided to break the plastic mounting tab rather than pay > Ј450. I did this by pulling the box down and toward me. I don't think the > box will be that much weaker without that screw.> 13. Under bonnet remove battery and clamp heater hoses. [[ KNOW YOUR RADIO > CODE FIRST!]]> 14. Back inside, take out the big fascia screw just below matrix and near > radio.> 15. Undo screw between two heater pipes [[A sod little x-head screw. See > rangerover link for talk about replacing with Allen head screw]]. Push > pipes back and up and catch no more than a litre of escaping coolant.> 16. Release clips holding matrix as if in a book's slip cover, and pull it > out (to the left) taking care to hold clear pipes and bit of fascia mount > near screw you removed. It just makes it.> 17. Instal replacement (Ј56 inc Vat from Peugeot), connect, top up coolant > etc."">

[[ Obviously use new O-rings ... maybe they were all that were at fault! > And get the x-head screw tight. Leave glove box out until you are sure you > have fixed leak! Reassembly is the reverse, but you may need chewing gum > or a magnetic screwdriver with some of the screws.]]>

[[I found that the replacement matrix did not go in all the way, though it > works fine without it. Subsequently a helpful posted pointed out that > sometimes there is a plastic cover off the end of the old matrix that gets > stuck in there if so you can usually hook it out(or remove the cover off > the end of yours). Subsequently to be tidy I hoiked out the matrix and > fixed this. Three years later - still no leak. Touch wood. ]]