Heater Matrix changing.

ghaddon1701 · Post by **ghaddon1701** » Thu Feb 24, 2011 10:31 am

Hi all,
Can anyone give me reasonably detailed instructions on changing the heater matrix in a BX please? Am I right in assuming it isn't as difficult as some?

Regards Graham Haddon

rmattila · Post by **rmattila** » Thu Feb 24, 2011 12:31 pm

It's slightly different in older models than in newer ones, so it would help to know the age of your BX.

Also, it's different in the right-hand driven models (the steering column is on the way, I guess?) from the left-hand driven ones, so I'm not the best person to give advice on that. But principally it's just taking the hoses off from the engine compartment side, and then removing the matrix from the cabin side.

ghaddon1701 · Post by **ghaddon1701** » Thu Feb 24, 2011 12:55 pm

Hi,
I have 1991 TZD Turbo. Right hand drive. I can see where the plastic piping is in the car. There is four small bolts where the matrix joins the plastic piping within the car. I just wanted to know in detail what needs to come apart inside the car to get it out. I can see that the steering wheel surround will come off quite easily. I know how to take the centre console apart because I changed the bulbs. But I can't see how the whole dashboard comes apart.

Regards Graham Haddon

KevR · Post by **KevR** » Thu Feb 24, 2011 1:10 pm

From memory there are a couple of small fastenings at about knee level on the A pillars, and some 10mm nuts from the engine side (accessed from the screenwash/heater motor area).
I have done a matrix without renoving the dash, a long time ago, and all I remember about it was it put me off for life...
If you take the dash out, then I think the worst bit is getting at the hose clips from inside the engine bay - especially on a TD.

citronut · Post by **citronut** » Thu Feb 24, 2011 1:26 pm

its been quite a while since i have done one but you dont have to remove the dash, and i dont remember disconecting the hose's in the engine bay either,

i think im right in saying undo the 4 nuts and bolts that hold the heater valve unit to the matrix kneck, and just push it away from the kneck a little bit,

then undo the two self tapper screws which hold the matrix into the heater unit body,

i think some say to undo the heater body mountting nuts and bolts, to allow the heater to drop a bit, so the matrix does not fowll on the streering colubm mountting panle which is welded into place,,

but i have done them without droping the heater body at all,

it is tight but can be done but take care on re/fitting that you dont srape the new matrix

regards malcolm

KevR · Post by **KevR** » Thu Feb 24, 2011 2:09 pm

citronut wrote:
i think im right in saying undo the 4 nuts and bolts that hold the heater valve unit to the matrix kneck, and just push it away from the kneck a little bit,

Now you say it, I think that's the way I did it the first time. Very fiddly though. Unfortunately I need to change the valve on mine as well, but then I also need to reconnect the cables to the valve, which have sprung off, so it may be easier in the long run to remove the dash.

Adrian E · Post by **Adrian E** » Thu Feb 24, 2011 9:27 pm

We dropped the top part of the steering column off its mounts to make space on our valver - had to remove the ignition barrel in the process, for which you need the key in the ignition with steering lock disengaged to allow it to slide out.

Don't remember it being difficult, just fiddly.

citronut · Post by **citronut** » Fri Feb 25, 2011 7:54 am

i cant see why you would need to remove the ignition lock, as this will float with the top section of the columb,

regards malcolm

Adrian E · Post by **Adrian E** » Fri Feb 25, 2011 7:58 am

We wanted the whole thing out of the way - I lose patience wriggling about in small spaces, especially if I'm balancing something on my chest whilst trying to perform micro-surgery! It's not difficult to remove so seemed the best option to improve access

Post by **Defender110** » Fri Feb 25, 2011 11:30 am

Adrian E wrote:We wanted the whole thing out of the way - I lose patience wriggling about in small spaces, especially if I'm balancing something on my chest whilst trying to perform micro-surgery! It's not difficult to remove so seemed the best option to improve access

Agreed, let the dog see the rabbit as my owd fella used to say!

ghaddon1701 · Post by **ghaddon1701** » Fri Feb 25, 2011 4:26 pm

Hi,
Thanks for your help everybody. It turns out it isn't actually the heater matrix that is leaking. It is leaving puddles underneath the car. Most likely to be the waterpump as it is all wet around the bottom timing belt cover. Further investigation tomorrow. New waterpump and belt at the ready.

Regards Graham Haddon

KevR · Post by **KevR** » Fri Feb 25, 2011 5:21 pm

I reckon it's easier changing a water pump than a Matrix!

Sadly I have to do both quite soon - on different cars.