Heater matrix replacement

johng

CCCUK Member
Over the past few months, I've noticed that my car is steaming up inside and I'm losing a small amount of coolant. My guess is that these 2 are linked and I have a slight leak in my heater matrix. Everything I've read says that for an A/C car, getting the matrix out is a real pain, but nevertheless today I started the job. So far it has taken me a couple of hours just to remove 2 sections of heater ducting.
IMG_20260320_164707.jpg
Still have a third bit of duct to remove before I can even start to get the heater box out. Looks like I will be busy this weekend.
IMG_20260320_164547.jpg
 

johng

CCCUK Member
Third piece of ductwork came out easily, just 2 screws that were actually reachable.
IMG_20260321_133505_441.jpg
The heater box itself was not so easy. I failed to get the hoses off the inlet and outlet without getting soaked in coolant (but I did get them off). The remaining bolts holding it in were fairly easy to get to, but there is very little room to get it out under the dash without risking cracking the dash. In the end I had to remove the bracket on top of the heater box with the vacuum actuator for the hot water shutoff valve and also the kick panel in order to remove the vacuum actuator for one of the heater doors.
IMG_20260321_133512_282.jpg
IMG_20260321_143311_685arrow.jpg
Then it was just possible to wriggle the heater box out (getting it back in is going to be fun).
Once out, removing the matrix is straight forward and I was very pleased to find a small puddle in the bottom of the box. At least I hadn't done all this for nothing!
IMG_20260321_144319_893.jpg
IMG_20260321_144344_267.jpg
 
Top