Air Conditioning (Alfa 33 907 Series)

April 20, 2020 60

Let's now move on to the most crucial part of our project; rebuilding the evaporator/heater unit. As you will see from the photos the rebuilt is quite challenging. The unit had surely seen better days - the evaporator cover has a big opening on the front and the coolant cut off switch is broken.

Let's see what hides inside.

Alfa 33 907 Series Air Conditioning > AC Evaporator Repair

This is the front view. Notice the damage created sometime in the past and the broken lever of the heater valve

This is the rear view showing hot/cool air servo motor and airflow direction ducts (direction feet)

This is the front part side view showing servo motor regulating interior/exterior air circulation, blower motor resistor, powerconnectors.

This is the rear part side view showing the air flow direction ducts.

This is the right side view showing A/C and heater piping. The alloy pipes are for the heater matrix and lower copper pipes are for the A/C evaporator.

Let's start by removing the front cover screws.

Remove the servo motor actuating rods by starting on the air flow direction motor on the rear side of the evaporator.

Then contine on the air recirculation servo motor actuating rod on the front side of the evaporator. Be easy on the plastic keepers as they are plastic and might break easily.

Remove bowden cable and heater valve bracket.

The complete pipe system is out.

Blower motor exposed.

Loads of dirt and dust inside blower motor gallery.

These are the interior/exterior air circulation flaps.Notice how the principle behind switching between the two modes.

The foam material is collapsing!

Proceed removing the evaporator side cover.

This is the evaporator piping. This actually delivers conditioned air; hot refrigerant in liquid form enters the lower pipe and having removed heat and humidity out of the passenger compartment, it exits through the upper pipe in gas form.

Remove the servo motor actuating rods for the interior/exterior air circulation flaps.

Time to split the evaporator covers. The unit comprises from two halves held together by many screws (either hidden oreasily seen)
.

Remove lower plate.

This is actually the drain plate of the evaporator.

Evaporator cases separated.

A clear and comprehensive view on the layout.