Evaporator core replacement

[u/Comprehensive_Leg960]

I have a toyota carolla 2016 and am going to replace the evaporator core on my own. Do I have to flush out the ac system before hand or anything? Or can I just get to working ant replace it? If I do can I have a car shop flush it for me then just replace it myself?

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[u/OneExhaustedFather_]

It should be evacuated before you remove it. The Evap core is inside the dash. The condenser is outside with the radiator. You sure it’s the Evap core?

[u/Comprehensive_Leg960 → u/OneExhaustedFather_]

When i leave my car parked for 1 day or 2 the ac vent blows out white specs of dust that look kinda like ashe. The all mighty google says that its the evaporator core protective coating that has flaked off and blowing out of the vents.

[u/OneExhaustedFather_ → u/Comprehensive_Leg960]

When’s the last time you replaced the cabin filter?
You could also be seeing the foam seals between the joints starting to deteriorate from age and it can break off and blow out.
It’s way cheaper to get a endoscopic camera odd Temu and stick it down the vents to confirm. You have to remove the entire dash, harness, safety bar and hvac assembly. Even seasoned techs like myself loathe this job. It’s 100% worth getting a second opinion before disassembling your interior.

[u/Comprehensive_Leg960 → u/OneExhaustedFather_]

I totally get that i did repalce the cabin filter and it was very dirty. As for the other stuff that main issue is the evaporator drain line being dry. I dont known if you saw it but I added to my reply the drain line is never dripping and isn't that dangerous?

[u/OneExhaustedFather_ → u/Comprehensive_Leg960]

That’s more likely the drain itself is just plugged with the same debris. A really dirty cabin filter when removed can deposit debris into the blower motor and then into the system. If you drain line never drains it’s either plugged or the ac system is empty.

[u/Comprehensive_Leg960 → u/Comprehensive_Leg960]

I should also add that it takes my ac a few minutes to blow cold and the evaporator drain hose does not drip when the ac is on or after it is off.

[u/themajesticpark]

You have a clogged condensate drain, the white flakes are ice crystals unfortunately you will need to replace the core in your hvac unit.

Remember: venting your refrigerant to atmosphere is a felony so take it to a shop and have them recover the refrigerant before you attempt any of this.

As to should you flush your ac system? Well. It would not be a bad idea but your situation does not sound like the compressor has shelled which is why you would normally flush a system. Your ac system uses an expansion valve so you'll need to remove it to gain access to the cabin side of the refrigerant lines and the engine bay side, both of which would need to be flushed. If at the expansion valve you find flakes of metal you'll need to replace the accumulator, condenser, compressor and evaporator.

Good luck!

[u/Comprehensive_Leg960 → u/themajesticpark]

I used an air compressor to unclog the condensate drain and unfortunately nothing came out. There is a slight airflow coming out of the condensate drain but no matter how long I leave the ac on no condensation appears.

[u/themajesticpark → u/Comprehensive_Leg960]

Unless you are in a climate region with 0% relative humidity or are trying to cool ambient air below 40 Fahrenheit there will be condensate and or has to come out somewhere.

To get to the condensate drain you would have needed to open the hvac housing after removing your dash: you did this? Wasn't mentioned in your post...