Help with AC fix

Hopefully you checked around here first and didn’t fill the system with Freon with regular PAG oil in it. The fact it worked for a day and then didn’t usually means you have a leak somewhere, and a big one at that. Unless you used Freon with PAG oil in it. If you did that you may have caused damage to the cooling system.

 

Your trouble codes indicate issues with the air mix and air outlet servos. You are lucky to have a Gen 2, where of the three HVAC servos, those two are both on the easy-to-reach side of the unit. One of them has a screw with difficult access behind another module that's in the way, but yitznewton found a tidy way around that.

Those issues are separate from whatever is going on with your refrigerant possibly leaking; I don't know what's up with that. If the car were mine, I think I would have started by troubleshooting the reported issues first, before anything to do with the refrigerant charge.

 

I differ in I would fix the leak first. Who cares about the doors if you are losing 20psi of Freon in a day. Plus if the evaporator is the part that’s leaking the dashboard has to come out anyway.

Edit: he does say he added more Freon and nothing happened. So I guess I would check the servos first then.

 

The "losing 20 psi of Freon in a day" is not something you can say by just looking, but only after choosing to frob with the refrigerant charge for some reason in the first place. The information available at the outset was only what problems the car was actually reporting, and that's where I would have started.

My comment was about the outset ("would have started"). If we're here now and the OP is sure, based on messing with the charge, that it is leaking, then yes, the leak should be found and fixed. I wasn't there to see the tools or techniques or what exactly happened, so there's more than one possibility I can't rule out from where I'm sitting. When a person decides to start poking at the schrader valves on the sealed system, sometimes part of what happens next may be self-inflicted. From here, I can't say.

That's the main reason at the outset I would have begun with what the car was reporting. It's an obvious place to start, without creating possible complications when they can be avoided.

 

Don’t even try to run the system again until it’s cleaned out by a superior cleaning system. Like a hecat. I can’t say if the compressor is damaged but you made a mistake.

People make mistakes, it’s human. Don’t fault yourself, just move forward. Sometimes a mistake is the best way to learn

 

1. The capacity of the system is 15.9 ounces of R-134a +/- 1.1 ounce.
2. The use of compressor oil other than ND-OIL11 was a serious mistake.
3. The factory repair manual advises that it is necessary to replace the evaporator, condenser and compressor if the wrong oil is introduced. If this is not done, a high voltage ground fault may result.
4. It will be very difficult to replace the evaporator as almost all of the instrument panel assembly must be removed for access.
5. After this is done, it will be necessary to use a vacuum pump to evacuate the system, then introduce pure R-134a into the system.
6. If a vacuum cannot be maintained, then some other part is leaking.
7. Get the factory repair manual info at techinfo.toyota.com and plan to spend lots of $$$ and labor effort to make this right.

 

There was an article (not sure exactly where at the moment, but I linked to it in another PriusChat thread some time in the last mumble months), suggesting a shop with a HECAT flushing rig (that type, specifically) might be able to flush everything adequately, if applied soon enough after the wrong oil entering the system. It wouldn't be a Toyota-approved replace-everything-in-sight fix, but it wouldn't be a Toyota-priced one either.

My main anxiety would be about the if applied soon enough part; if I remember right, the article's authors were thinking of a quick "yikes! I put in the wrong oil" scenario, not one of it sitting in there for some days or longer.

 

At this point I would think the hecat flush would be the cheaper option. What’s the worst that could happen, it fails and you replace those parts anyway?

 

Unfortunately you cannot use a flush kit well the expansion valve or orifice tube are in the system when the expansion valve or orifice tube are easy to get under the hood and only take 15 to 30 minutes to replace you bypass tube them with a solid open tube unfortunately in most older Prius the expansion valve is under the dash located with the evaporate tour. PAG Oil does not cause immediate damage it’s a long term problem over time . Just like leaving moisture or air in the refrigerant system does not cause immediate damage it’s a ticking time bomb that causes failures later on .

 

The most important thing is to try to diagnose an air-conditioning problem with a correct charge of refrigerant this is not something that you guess at and you do not determine the charge of air conditioning by using pressure it is done by weight only. 1: you completely recover all existing refrigerant out of the system. 2: You put a vacuum pump on until you achieved roughly 500 µm or below deep vacuum. 3: Then you fill the refrigerant by weight only determined by the under hood sticker that is usually yellow on a Prius depending on the Prius can be anywhere from 420 g to 580 grams you have to follow the sticker under your hood different years and models have different weight capacities of refrigerant.
4: now we have to deal with finding your leak hopefully you or somebody else has installed a good quality UV trace dye but this is only finding very big leaks or leaks that happen over a long period of time and if the leak is in a place that you cannot see with your eyes it will do no good. 5: this is where a skilled technician with experience and a high-quality professional grade electronica refrigerant leak detector preferably one that the factory provided a calibration bottle so the leak detector can be periodically calibrated to prove its accuracy and sensitivity. In the automotive technical field this is where are you weed out the men from the mice most shops or technicians are too cheap or uneducated to buy the better leak detectors to actually to perform a quality job. After filling the vehicle with refrigerant the technician will go over the entire system to try to pinpoint the leak. On the Prius the condenser is the number one culprit for your first place to look for a leak. When the Prius gets a little older with some age and mileage the evaporator is the second most common leak. 6: most importantly keep people away from O’Reilly and other auto parts stores that sell those big cans with a little funky gauges attached to them that are highly in accurate with other chemicals mixed with the refrigerant other oils with leak sealer‘s and a special super lube synthetic extra cool additives these do it yourself cans are poison to the electric compressor on a Prius. It sometimes may work out first and the customer is really happy that they got cold air but after one or two or more times a fill up with the snake oil the owner of the car ends up buying a burnt out compressor then the condenser Hass to be replaced all the lines need to be flushed the expansion valve needs to be replaced just because of good advertisement to purchase Snake oil cans. Just like the phrase ( Friends don’t let friends drive drunk ) in this case ( Friends don’t let friends buy cans of refrigerant from O’Reillys ) lol