Cleaning the a/c evaporator

[warthog]

When Andy and myself had the heater ducting out yesterday to replace the evaporator, we looked at how we could get to it to clean the matrix with the unit still in the car.

I've just done mine, and as long as you're careful it's a very simple job. (Took me 1/2 hour)

You need to remove both the heater fan and the fan resistor pack from the ducting. This then allows you access to the 'outside' face of the a/c evaporator. Using a torch, small paintbrush and VERY CAREFULLY the thin nozzle on your vacuum cleaner, the matrix can be brushed clean of debris and vacuumed up. The matrix is fragile so DO NOT POKE at it.

If your car has been run without a pollen filter in it then chances are you will find a mass of dead insects and road grit packed into the matrix, just waiting to trap moisture and corrosion.

If your heater fan squeaks then this is also a good time to brush the dirt off it and spray some lubricant on the bearings.

Cheers

[sholtby]

I'll have ago at doing this sometime as I know they commonly fail. Thanks for the tips. I'll try and fit a pollen filter also.

Simon

[tonyflynn1]

Thanks Brian, my fan squeeks and there's no pollen filter - I'll have a go at this over the next couple of weeks. Is it a big deal to remove and refit the fan?

[Andy Mcl]

All you need is a number 20 torx I think, to undo the screws.
You will obviously have to remove the glove box - six torx screws and the under dash shelf 2 torx at the front. Then you can get in very easily.
BUT I reiterate GO CAREFULLY, the evaporator is VERY DELICATE.
If you have muck in there then I guarantee you either do not have a pollen filter in there or it has split open.

If you want to save your evaporator FIT A POLLEN FILTER it only costs about £35, this includes the mounting bracket.

This I believe it affects all 850's and early V70's

Brian's cleaning method also tells you if you have a big problem later on.

My ECC is now awsome, nice and cold well worth the time to do the repair job.

[sholtby]

With later Volvos an hour or so after switching off the fan runs to dry out the evaporator for a few minutes. I wander if we could fit a circuit to do the same to our cars?

Simon

[warthog]

Simon,

there is an aftermarket Volvo extra that can be fitted that adds a timer to the fan motor to do just the job you note. I found it by accident on VADIS but I have no kit part number I'm afraid. It's called a 'Drier Unit for the Evaporator'

It cannot be fitted to any 850/V70 with ultrasonic interior alarm protection as the fan operation will set off the alarm.