E30 Zone

Does anybody know how to replace the heater matrix , mine is leaking into the drivers footwell, I think previous owners had some trouble and may have used radweld , I have replaced the heater valve and the main rad

Cheers

It's removed from the passenger side footwell. But I'd confirm that it is the matrix which is leaking before removal if possible, as the majority of these create puddles in the passenger side and not the driver's footwell. Are you losing water from the cooling system?
Remove the under dash cover below the glovebox and you'll see the two pipes exiting through the bulkhead. First remove the two pipes feeding the matrix from behind the engine, remembering which way they go back on as it is important.
You should see there is a valve on one of the pipes inside the car, this is the cold air switch and is also prone to failure and leakage.
It's a fiddly job so expect a cricked neck at least but as you'll see when you're in the passenger footwell there are only a few screws holding the matrix onto the heater assembly. I've found it easier to first separate the pipes with the valve attached. Once these are disconnected and the mounting screws removed, it's just a matter of sliding the matrix free of the enclosure.

Fitting a replacement is pretty much the reverse of this then. Good luck. I've replaced two of these myself.

P.S. Which heater valve did you replace?

P.P.S. There is some info on the Wiki page:
http://www.e30zone.net/e30zonewiki/index.php/Heating

Thanks for reply , the heater valve I replaced is what I think you are calling the cold air valve , the one with the bugger of a screw to get out!
I am pretty sure it is the matrix as I said I think it is blocked probably by some sort of radweld
Cheers