Air con drains

[Ian Simmonds]

I've started getting a slight run of water into the passenger footwell of the S2 and a 'puff' of vapour when I turn the heater control away from cold with the Air Con running... It appears the water arriving in the footwell is running down next to the central footwell heater tracks. The water is odourless, suggesting it's condensation rather than coolant. (I'm hoping it's not the matrix) But where does the Air Con drain condensation from, as it appears to be worse after the air con has been running for a long time.

I'm pretty sure it's not a windscreen water leak as it's been running water even through the recent dry spell.

Any thoughts?

Many thanks in advance

Ian

[Ian Simmonds]

For those who are interested... it's the matrix... I'll set too at some stage but any suggestions on the work process, it's an Air Con ABY....


Ian

[Skull]

dahsboard out, klimabox out, heater matrix out, replace matrix, klimabox in, dashboard on. one day of work.

[Ian Simmonds]

Thanks...

So am I right in saying the A/C needs de-gassing first?

Eveything else is dis-assembling and re-assembling.

[johne]

Two possible problems here: condensed water leaking into the car or a fault with the matrix.

The only possible fault with the matrix is that it has a leak in it or the low pressure switch that is screwed into it. If that's the case, the gas will have already escaped - since it's under about 40 psi of pressure when the system isn't running - so there's no need to degas.

The other problem which is much simpler, cheaper and easier to fix so should be checked out fully first is leaking condensate water from the bottom of the matrix housing into the footwell. The drain hose runs from the bottom right hand corner of the matrix housing using a specially shaped rubber pipe out through a hole in the firewall into the engine bay underneath the steering rack. It's only a push fit onto the matrix housing so check a passenger's foot hasn't kicked it off or that the drain end in the engine bay isn't blocked causing the condensate to back up.

If the matrix has a leak of gas, it won't be long before the air-con stops feeling cold as the function of the associated low pressure switch is to stop the compressor from running if there is low or no gas pressure.

[Ian Simmonds]

Thanks for that John

It's definately coolant in the footwell, I suspected initially it wasn't but I put about 500 miles on the old girl last week and the leak has been sufficient enough to not only identify the pinky, almost slimy feel to coolant, but also to drop the level in the header.

I've subsequentally by-passed the coolant feed to the Matrix by joining the pipes at the bulkhead.

The air-con is fine at the moment and belting out plenty of cold air.

When I get back home at the weekend I'll still look at those drains though - because I've had my doubts about them for a while.

Cheers

Ian

[johne]

Pleased for you that it isn't the air-con matrix but having said that, getting to the heater matrix to replace it is still a lovely job since it means dashboard out......
Others may correct me, but I think you'll be able to replace the heater matrix without degassing and removing the air-con matrix since you can undo the clips holding the central heater section - once you've removed the dashboard - to the air-con matrix section so that you can extract the heater matrix feed pipes from the bulkhead and out the top of the centre section