Very slow AC leak

[ncszot84]

2019 expedition loses AC coolant slowly over about 6 months. Happened twice now. Dye with uv light and handheld sniffer not turning anything up. Any ideas for where else to check that are notorious slow leak spots on this vehicle? The shrader valves were replaced but not the caps. Thank you,

 

[DWs-TTEB]

I had a similar experience (Aug 2023). Took it to my service place, and they removed the dashboard after putting dye in the system and found the evaporator coil (passenger side not far from cabin air filter) was leaking and they replaced it. I had them check the coil in the back and they said it was fine. My extended warranty paid for all this. Alls well to date. This repair cost $2,232.00 USD.

 

[DWs-TTEB]

I then had the wet carpet issue big time after this. So I did that TSB my self installing that rubber elbow at the ac drain port on the firewall.

 

[1111ExpyEL1111]

Ouch. I have the same problem in my 2012 Expy. Is there a way too see if the leak is in fact behind the dash? 2 checks with the UV light aren't turning up anything.

 

[Grey ghost]

I had to replace both front and rear evaporators

 

[JKautz]

Our 2020 max had the rear evaporator replaced under warranty and that fixed our small leak. Took the dealer 2 weeks to find it. I think I’ve seen a few other complaints about the rear evaporator being a problem. Might check that area out?