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Replacing Evap Core in 2009 Toyota Matrix

My sister’s Toyota Matrix is spewing aluminum oxide dust/powder whenever she turns the blower on. Best I can tell the evap core is disintegrating. Since the repair is rather expensive, I’m thinking of having a garage evacuate the system. Then I will drive the car home, spend however many days dismantling the dash and replacing the core. After I finish, I’ll take it back and have them recharge it.
Does this sound like a safe thing to do? Should I pull the fuse/relay for the compressor just so it doesn’t turn on accidentally with no fluid? I understand the amount of work needed to strip the dash and I already have the factory service manuals for it.

That plan would be fine. Have you tried cleaning the evap core and ensuring the evap drain is clear? There are chemical cleaners that are sprayed in that may solve your problem. The a/c compressor will not engage when the system is discharged. Try to limit the amount of time the system is open or you will also need to replace the desiccant bag.

Does the AC still work? A 5 year old Toyota (or any) evaporator disintegrating like this is hard to believe.

Has she replaced the cabin filter. I have never heard of metal dust coming out of the vents.

aluminum oxide dust/powder

Are you really sure that is what it is?

I’m also having a hard time seeing a 2009 Toyota evaporator desintegrating and especially so if the A/C still works well.

I have replaced a few evaporators on vehicles 2-3 years old. They produce a lot of white dust from the vents when first turned on.

The are bulletins for the 2006-2011 Avalon, Camry, ES350 and RX350 for this but not the Corolla/Matrix.

Some vehicles may exhibit a condition where dust or powder is visible from the HVAC vents. A newly
designed evaporator and HVAC system cleaning procedure has been developed to address this
condition. The procedure listed below details evaporator removal, HVAC system cleaning, blower
motor cleaning, and installation.

@Nevada_545‌- Wow. Never in a million years would I have believed that one.

I like your plan. Yeah, it’ll be safe to do.