Refrigerant Replacement

You can rent R-410a gauges and the vacuum pump at O'Reilly or I think the others as well for free too.

 

Out of my depth, but: Toyota Prius AC has a special oil, and Toyota Repair Manual cautions against using gauges that have been used with other oils.

With AC, my pref is to just leave it to the dealership.

 

I'm not sure that'll save the dealer much work, unless you're thinking of pulling the vacuum just as a test to confirm your repair holds before your visit.

They wouldn't really be doing their job without evacuating the system to their own standards before their own eyes anyway, and whatever vacuum you pulled will likely be lost between you unhooking your connections and them connecting theirs.

 

Yeah, concur. Will look again.

 

@C-in-DC The whole shebang:

 

I like the photograph on page 14 what is called the heated charging cylinder. This is how you can tell when they copy and paste from old publications..

That charging cylinder was used when my dad was young back in the 1950s and 1960s through a little bit the 1970s.
That is the same charging cylinder by Robinair that I learned on in the late 1970s that was my dads.

And you really know you’re reading old re-edited refrigerant text if you have one that talks about using R11 as a flushing agent.

 

When somebody asks if a vacuum is needed or just use gauges, it is time to let a pro do this job. Realize this is a variable speed three phase compressor that if ruined will cost you a compressor, condensor, txv and repeat purchases of refrigerant and dryer. Along with a possible high voltage fault for the hybrid system. All of which is normally very reliable.

Replacing oil in the system if not easy since most is probably still in the system. It is almost sure to have absorbed moisture so you hope a long evacuation removes the moisture along with the air. Otherwise the compressor windings and bearings are at risk.

Don't even think about the costs if the evaporator gets clogged up. Complete dash removal.

 

I would not be afraid to take it to an independent. Just ask them if they have worked on Prius variable speed electric compressors (which are not typical in conventional cars) and ask what oil if any they would add. I would want to know if they evacuate for an extended period and then charge by weight.

 

I had a lot to type but essentially you are going to want to remove the ac compressor from the prius and dump out the old moisture absorbed compressor oil, and refill it with the correct amount of nd-11 fluid (or probably the correct way toyota will do it is a new replacement of the compressor only). Try and do it on a day without rain and as little humidity as possible. When you do that, you will want to reconnect the system and get it all readied up to be vacummed as soon as possible to reduce the amount of humidity entering the system with the new compressor oil. Then I would vacuum the system for a couple hours with a new gauge set that is compatible with our system, turn off the low pressure side valve on the gauge, then turn off the vacuum pump and disconnect the pump. Then when you get your refrigerant tank connected you just purge the upper fitting at the gauge to get all the air out of the line, set your refrigerant tank on the weigh in scale, set your tare, and weigh in the correct amount of refrigerant and when you get it charged up and the pressure switch is satisified it will kick on and start running the loop in the refrigerant system. Since its variable speed they say not to worry about the pressures too much if you are doing a fresh evacuation and recharge and just make sure you add the correct amount of refrigerant by weight only.
*You can also vacuum the system and suck in the correct amount of nd-11 compressor oil through the high side with removal of the shrader valve

 

I hate to sound like a broken record (does anybody get that reference these days) but shop around and....

I would not be afraid to take it to an independent. Just ask them if they have worked on Prius variable speed electric compressors (which are not typical in conventional cars) and ask what oil if any they would add. I would want to know if they evacuate for an extended period and then charge by weight.

....Personally I would not add oil on a R134a system unless it was obvious oil was all over the place. The dealer will remove the compressor, clean it out, probably put in a new txv and dryer, properly evacuate and charge by weight. A new dryer and extended evacuation is what I would do followed by weighed charging using in R134a.

Sometimes you have to go further than five miles to find the skilled independent. I would go 60 miles to save $1,000. Its up to you. If you want easy go to the dealer.