Replacing C-Max Heater matrix O-Rings (2005)

whizbang

The car is mid 2005 registered, Build date approx 12/2004. 1.6 Petrol.

So after a few weeks of leaks, we brought the car to out trusty local mechanic, who sweated and swore he had done the job, only to have boiling water and steam fill the car a few days later.

Ford's official fix says take out complete dashboard and install new heater element (along with O-Rings). About €1200. - No Chance.

Trawling the net i found the tip about a platform level with the car ; its So much easier to lie down when looking at this..

Where to Start:
First thing is to remove the Drivers seat. Do this to remove the carpet also. 4xT50 Torx, and dont forget the connector underneath.
Next unmount the center console; 2xTorx and 2x10mm bolts.
Pull up handbrake till it points to the sky to make this easier. Then remove the Dash lower cover.

Undo the 4 nuts holding the gearshift mounting and just leave it to one side. No need to disconnect anything.
remove the Gearshift mounting frame. There's a bunch of bolts; 10mm, 2x12mm and another torx screw. I think the earth mount is 7mm.
Its easier to remove the frame if you leave the 2 lower sections that bolt to the floorpan, but you need these away for later.

Pull away the Air duct and you will see the Heater box housing is made up of a bottom tray and the top section is in two halves.
Undo all the torx screws that hold the bottom tray up into the top sections, then there's a few left for the left and right halves, along with a couple of clips. Be careful pulling away the top sections, they aren't all that tough.

Now you need the 8*4 suitably cutout and a few props :

(yes its a big mug)

A piece of 2x1 is used up under the clutch pedal mounting to keep it down out of the way.

Now you can get at the pipe joint clips easily. Then push down on the lower tray part of the heater box, and lift out the heater matrix.

Twist it up from the left side to clear the box and allow you to pop out the pipe joints.
No its not rust. Its just the coolant colouring mixing with the foam strips.
Its all Aluminium, so wont need replacing unless you have run it leaking for years.

To Test, fill to the brim with water, press your thumbs over the top of the pipes and feel the pressure. If its leaking you will feel the pressure drop.

Here's my trouble: you can see one missing and one damaged Oring.


Found the missing one:

Yes its rotting.

Use plenty of grease on the NEW Orings, fit them into the grooves in the inlet pipes, but make sure they are well seated. If there's too much grease in the grooves, the Orings wont seat properly. Use plenty of grease all over the heater pipe ends and test fit.
I used a piece of foam on the bottom end of the heater core where it touches the heater box tray to help hold it up against the pipes, and hopefully reduce the chance of it rattling.
You may need an assistant to push back on the top pipe from the engine bay, but i found the piece of foam held it for me.

I found it quite easy in the end, about 4 hours tops (with buckets of tea) BUT don't even think about it unless you have the platform to work on.