AC Works fine, but only if temperature is below 80 degrees outside

You’re likely just low on refrigerant. Be careful to put the correct refrigerant in your Prius, these cars use a different type of oil than most cars do.

When I did mine last year, I used a can without any oil at all to be on the safe side.

 

Go to service garage that provides for free (or cheap) A/C diagnosis. Get them to write up an estimate of what is needed.

The information that you especially want is the following:

1.) where is the refrigerant leaking from?

2.) is there evidence of substantial refrigerant oil leakage (if so, should be at same location as the refrigerant leak)?

3.) can they top off the A/C system for your GEN2.

Remember, GEN2 system capacity is as follows: i.) refrigerant capacity of 15.9oz (almost 1 pound); and ii.) 4.5 fluid ounces of ND-11 refrigerant oil.

Also see prior thread on recharging Prius AC system: Recharging '08 Prius A/C system | PriusChat.

 

Go to Walmart and buy a can of this Freon,''this freon has no other additives'' [do not get another brand] and also buy this adaptor to add the Freon

= You probably just need a couple of 'ounces' of Freon=DO NOT OVER FILL

 

Inaccurate posting deleted.

 

Whatever you do... Don't buy recharging cans from the store, they'll make things way worse not better in the long run. Most people have a failed AC system soon after they use those cans because they aren't designed for more modern complex systems.

To properly do maintenance on an AC system on Prius and most other modern cars where internals pressure changes based on what stage of operation the system is in you need the equipment necessary to measure air temperature & humidity outside the car, inside the cabin, as well as inside the system. That's six different measurements and that not even getting into measuring the amount of oil and refrigerant in the system, as well as other more subtle measurements.

Spending a couple hundred dollars on servicing from someone who uses the very best gear all day every day is the way to go. @lech auto air conditionin on here has written extensively on PriusChat about what kills and what saves A/C systems and while I have no problem working on a aspect of a Prius, all his writings have convinced me this is one system I don't have the expensive equipment or experience to do correctly.

 

SUPER TECH 134A from Walmart =is pure 134A with no added additives- works great on the Prius A/C system

I put some on my Prius 5 years ago and is still Cooling Perfect.

***Do not over fill
Make sure you use a new adaptor and that the hose is not contaminated with another Freon.