How screwed am I? >> recharged with leak stop and R134a

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by labumm, Jul 25, 2025 at 2:21 PM.

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  1. labumm

    labumm Junior Member

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    I did a stupid thing. Instead of charging only R134a into my 2010 A/C, I also added Supercool A/C Leak Stop + UV dye. The system seems to be working fine, but as I belatedly read that ND-11 oil is used.

    How screwed an I?

    here is the link to the product:
    R134a Seal Leak Stop with UV Dye 4oz - TSI Supercool

    This was only a couple days ago, so Maybe I can take some remedial action. For example: bleed about half of the refrigerant as liquid from the high pressure side into my recovery tank and then replace that with fresh R134a. That should remove some of the oils. If I remove half of the refrigerant each time after 4 cycles, I'll be down to 10% of the leak stop. I'd need to add back some proper oil to make up for what was removed. How crazy is this plan?

    Another question.

    Is the "conductivity" issue with the conventional PAG oils (v ND-11) due to them being hygroscopic (wet)? I'd think think there is a drier in the system.

    In my residential HVAC with R410a and POE oil, the issue is water. In that system the windings of the motor are also exposed to the refrigerant. If it is "wet" then you can get electrochemical corrosion of the wires. The metal ions then released into the oil increase the conductivity further leading to compressor failure. Anyway, that's why after opening the system you replace the drier, keep it purged with dry N2 while working in it, and pull a good vacuum on it before recharging.
     
    #1 labumm, Jul 25, 2025 at 2:21 PM
    Last edited: Jul 25, 2025 at 3:28 PM
  2. ChapmanF

    ChapmanF Senior Member

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    If the wrong oil has been put in the system, and is discovered quickly, there may be some recovery possible. This thread links to an article where a shop added around 150 ml of the wrong oil to a system, used the car for a couple of days, then replaced the compressor and flushed the entire rest of the system using a HECAT H-1000 flush system, and recharged it with the correct oil. The system was still ok 49,000 miles later.

    Replacing the compressor may be an expense, and I do not know whether HECAT flush systems are available nearby. But it is less labor and expense than having to replace more of the A/C system.
     
    #2 ChapmanF, Jul 25, 2025 at 3:41 PM
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  3. labumm

    labumm Junior Member

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    That is an interesting article. In note that Supercool is also mentioned. Maybe I am over thinking this. ND-11 is a POE oil. And the Supercool product uses 2 oz of "universal" POE. (see side panel below) On the other hand, the initial oil charge for the compressor is 4 oz ND-11, so now it is 1/3 Supercool "universal" POE and 2/3 ND-11. I do believe that dose makes the poison, meaning that the system should be able to tolerate some contamination.

    Anyway, I just got off the phone with an engineer at Supercool. He told me the product was fine with the hybrid electric compressors. So maybe I'm OK after all.

    I understand the concept of the HECAT flush. That basically does a liquid solvent flush. Sounds like a great system!

    upload_2025-7-25_14-59-59.png
     

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    #3 labumm, Jul 25, 2025 at 4:15 PM
  4. PriusCamper

    PriusCamper Senior Member

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    There's several things you've done here that could cause the untimely demise of your expensive AC compressor. Too much or too little refrigerent or too much or too little oil can cause damage.

    The main challenge is that Prius AC is a variable pressure system and the amount of oil and refrigerant is based on a precise weight. The best way is an AC specialists has an expensive machine to evacuate the whole system under vacume and then put the correct amount in by weight. The DIY way would be estimating the weight of the refrigerant and oil by comparing full cans with empty cans and putting it in a fully evacuated system.
     
    #4 PriusCamper, Jul 26, 2025 at 5:05 PM
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