A/C System Repair (Condenser)

We have no A/C cooling on our 2012 Prius V. We are currently in an abnormal heat wave (40 °C today) but we have stopped using A/C as the refrigerant is likely low and if it’s not too late I’d like to avoid burning out the compressor.. About a week ago, the A/C was anemic but I cannot say how long before that the performance was dropping.

I have learned a lot from the videos, posts and information provided by Tom Lech (lech auto air conditionin) especially regarding the Prius A/C system. Thank you Tom! I have not yet found a “Prius” focussed shop or a person like Tom with the expertise in automotive A/C systems in our area (Nanaimo, BC) so any advice on local services would be welcome. I may be forced to use the bandits at the dealer.

From what I can tell, the right shop/technician should have separate dedicated gauges for R134a/ND 11(POE) oil, separate dedicated recovery equipment for R134a /ND 11(POE) oil, have the correct oil and dye on hand, able to test refrigerant purity , and able to log and print the evacuation and hold test. Anything else to look for?

I have borrowed an H1Pro refrigerant detector and confirmed a stain on the lower driver side corner of the condenser is a small leak at the bottom of the pipe on the side (receiver?). This seems to be a common spot. I also let the car sit and put the detector probe in the front centre vent inside the car and turned the fan on low but did not detect anything. I could not see any other oil stains from leaks on hoses etc.

When the A/C is running under load, I can hear the compressor running and I can see clear liquid refrigerant mixed with what I think is a significant amount of gas refrigerant moving through the sight glass . There is no discolouration or visible contaminant in the sight glass. There is no sign of dye having been added. I believe the compressor frequency I hear is matching the frequency of a full speed compressor in one of the lech videos.

My questions:

1. Tom is pretty adamant that a service person should test fill first and not assume the condenser is the only problem. Is there any other way to confirm the compressor is good other than to recharge and test run?
   
   
2. I’m told by one shop here that in BC they are not allowed to fill the system if there is a known leak. Does anyone know if they are permitted to fill the system for testing purposes like Tom does?
   
   
3. Is there a risk of drawing moisture into the system by doing the test which requires two recoveries prior to fixing a known leak?
   
   
4. After recovering the test charge, can this refrigerant be reused?
   
   
5. He always adds dye. Are there any drawbacks?
   
   
6. He has a pretty wizzy set of gauges with temperature probes etc. Is this a requirement for doing a proper job or can a tech use old school stuff as long as they have an electronic micron gauge?
   
   
7. I know Tom is against the use of aftermarket condensers but he has also commented that the aftermarket now is much better than they used to be. Are there any aftermarket brands that are worth considering?
   

To ensure this repair is conducted properly, I’d like to confirm my understanding of what needs to happen once I pick the shop/technician. Please chime in with any corrections.

1. Recover and measure current charge to determine how low the system is.
   
   
2. Add dye and charge the system by weight. (They might not agree to do this.)
   
   
3. Run and test system performance compressor performance. Judge compressor..
   
   
4. Check for other leaks.
   
   
5. Prep the car to remove the condenser
   
   
6. Recover the refrigerant (and measure the recovered weight again?)
   
   
7. Should the recovered gas at this point be tested for purity and reused or tossed?
   
   
8. Fill the system with dry nitrogen. To what pressure?
   
   
9. Release the nitrogen pressure back to atmospheric
   
   
10. Install the new dryer pack in the new condenser (is this already installed in a new condenser?)
    
    
11. Unbolt, disconnect fittings and remove the old condenser
    
    
12. Immediately after disconnecting the old condenser, install the new condenser and connect the lines with new o-rings.
    
    
13. Evacuate the system down to less than ??? microns.
    
    
14. Let the system sit and confirm it holds vacuum. Ideally logged and with a printout.
    
    
15. Add dye if not
    
    
16. Recharge the refrigerant by weight.
    
    
17. Add the required amount of POE oil (ND-OIL 11) for a condenser replacement (40cc).
    
    
18. If dye is added it must be compatible with POE, Ester Oil Based (eg. Tracerline Fluoro-lite 5 Universal/Ester Dye).
    
    
19. Check and test.
    

Bonus question: above our cabin filter, we have a rectangular hole on the air box but the edges of this hole are rough. We did have a rodent problem. What is this supposed to look like? Anyone have a photo?