Hoses going to the heater matrix

Found my way to the heater matrix via the passenger footwell panels. All looks well with it BUT there is a slight weep of coolant coming along the lower heater pipe from the far side of the bulkhead. I suspect a weeping hose or something as I'm not really losing any coolant from the expansion tank at all.
However, how do you get to those hoses that go to the heater matrix? Is it down from the top by removing the panel under the heater fan and battery? Or do you get to these from underneath. Last time I was underneath changing the hoses to the radiator, I couldn't see where these heater hoses went.

Thanks in advance

The go into the matrix just below the battery tray .So yes from the top .They then go to the two main rad hoses just as they meet the solid front to rear pipes ,you need to remove the protection plate and get underneath to do the other ends .

Thanks Lee.

I reckon that I've got a plastic panel under the battery tray that covers these up. I'll have a closer look directly under the battery tray.

Thanks again

Jon

I think I've finally got to the bottom of why I sometimes get a damp footwell.

I watched the hoses on the interior side with engine and heater going the other day and not a thing in terms of a leak.

However, after a while (once the engine was properly warm - even though the heater was blowing warm for ages) I noticed some slight wisps of steam appearing to come from underneath the heater system. As I say, no sign of any weeps or drips from the pipes and plastic heading into it.

So, I'm thinking that there's a leak in the heater matrix rather than the pipes. When I turned the heater control to cold rather than hot the wisps went away and came back very slightly when I set it back to hot. This is something I reckon I can live with over the summer but a bit of a pain in the winter.

The question is, how hard is it to get at, evaluate and replace the heater matrix? The workshop manual suggests a full dashboard-and-centre-console-off. Looks likely but I was wondering if there were any fiddly work-arounds or special tricks?

Thanks.

No way round it I'm afraid .
The matrix itself you can see if you remove the side panel ....it slides out towards you but the pipes go through into the bonnet at 90 degrees make this impossible to do without moving the whole heater assembly back ...
Center console removed and dash freed off/pulled back to allow access .

I'd U the pipes to bypass the matrix and see if you still get wet before pulling the interior apart

When I turned the heater control to cold rather than hot the wisps went away and came back very slightly when I set it back to hot.

BTW the heater control does not shut off the water to the matrix, it only redirects the air away from the interior when it is set to cold. The heater matrix is part of the cooling system and, according to the manual, aids the rad in extra cooling.

Yes ,as John says you will still be getting flow through the matrix on cold , bypass it and see if you still get wet feet ....
I've bypassed mine on JIL with no ill effects but then I'm running a huge rad .

I don't really buy the aiding the main rad, as the circuit sits in parallel to the main rad with far less airflow , at idle yes may be. It saves on adding an extra auxiliary pump, given relative flow / pressure losses with the long circuit, but basically dumps hot water back past the main rad to the engine… not so good in a performance application chaps. Further, if that had really been the case, then the A610 wouldn't run a more conventional circuit than the GTA... well that's my opinion

Thanks guys,

I know that the matrix is always "on" as it were but I'm only seeing the wisps of steam when the heater control is on hot. Is the hot/cold control just controlling airflow rather than hot water?
Maybe this is a co-incidence but the other thing I'm noticing is that back in January, I had the heater on full whack for a couple of hours and noticed a drop in coolant later on (it had leaked). I came back with the heater at 3/4 or so (still warm) and lost no coolant. I'm wondering if the position of the control is bending some plastic to cause a wee leak.
Thanks for the photos of the matrix coming out the side of the unit - I've noticed that I've got a small brass screw missing from the bottom of that. There's one at the top but an empty hole at the bottom. Of course there are a bunch of clips. Maybe if I get that screw back in there it would help?

You can tell I'm looking for any excuse not to get the dash apart. Even thinking of making some sort of 'coolant catcher' to help keep the carpet dry!



Thanks for your help

Jon

The water is always flowing through the matrix .The control lever has nothing to do with it leaking ,it doesn't control water flow and goes nowhere near the matrix

Isn't that right people ??

That's how I understood the system to work. Struggling to understand why I'm only getting wet feet (well my passenger is, not me!) when the heater's turned up to red but not otherwise. Unless there's a crack in the matrix that is opened up when on HOT because of plastic bending somewhere.
Either way the heater matrix isn't well but symptoms are 'manageable' in the short term...

I reckon until it's pouring out all the time, I may well live with it at least until the end of summer - or something else prompts me to get the dashboard apart. Or a trip to RATS

Paul Sage told me a while back that he'd got a solution to taking out the dash / seats / console / steering wheel. He'd basically come to the conclusion that it was getting harder to remove all the above (rusted bolts etc) and costs were getting prohibitive since it's such a long job.

As a result he made up a template to use to cut through the glassfibre bulkhead and extract it that way. It's quite a small opening cut with a dremel and he then has a new plate that goes back in as an access panel.

Seemed a sensible solution and turned it from an 8 hr job into a couple of hours max.

Someone on here must have had it done that way. I know when he did mine years ago it was the old route of most of the interior coming out!

Not sure about that .Seems as long as it is wide to me + you're damaging a sort-after classic
It would have to be a big long slot ,8"x 2" and you'd take out the support for the battery tray and run into some structure as well as far as I can see .

Struggling to understand why I'm only getting wet feet (well my passenger is, not me!) when the heater's turned up to red but not otherwise.

Might I suggest that what is happening is this:- When the heater control is in the cold position, the redirecting air flap opens up and directs the air out through the bottom of the car together with any water leaking, or wisps of steam from the matrix, but in the hot position, this flap is closed and therefore this path is not available for any leakage, water or wisps of steam, to be dropped out, so it has to find somewhere to go, and therefore depoits the leaked coolant through any joint in the plastic moulding into the car, and as the easiest way out is where the matrix is slid into the housing, and as that is on the passangers side.....hey presto

When in the cold position the matrix is isolated from the incoming airflow completely ,the hot air just sits there in the chamber ,it is not expelled .
The flap seals the matrix chamber off from the incoming air .
Cold or hot the leak will always be there if it is coming from the matrix .
Sure it doesn't do it more when it's been raining ??
Isolate the matrix with a U pipe for now and see what happens .