A/C Lower Line Leak

The best fix would be to braze/solder using any number of aluminum alloy products. The following is video of one I found.

 

That kit seems like a reasonable approach. However if you intend to recharge the system yourself, you will first have to apply a vacuum pump to draw all air out of the system, prior to recharging with R-134a refrigerant. By the way, the correct refrigerant would be "regular stuff" R-134a, however you don't want to use refrigerant that contains compressor lubricating oil. Use of incorrect oil is the concern, as it may cause a ground fault with the electric compressor motor.

 

Scotty the clown is a joke. Entertaining-yes. Some of the stuff he says and does, is scarry.

Splicing will NOT hold up over time. The best long term repair is replace the part or spot weld.

For the future, rule out leaks before recharging! The AC system is a closed system. If you have to recharge, you most likely have a leak: failed seal, physical damage (ie front end vehicle accident or debris hit the front condenser), or component failure. Fix the leak first, then recharge. Assuming NO leaks, you would only need to add very little refrigerant.

Ignorance is expensive: time and money. If you can't be bothered to go to your local library and get an automotive HVAC manual to learn the general basics, seek professional help.

B/C all vacuum pressure will be gone when you apply the crappy splice. As it stands right now, there is probably NO vacuum in the system due to the damaged part.

FYI, proper repair protocol is to evacuate the AC system before attempting a repair; a shop would connect the AC system to special equipment that will suck out all the R134a gas in the system.

Also, the Prius uses special electrical compressor oil, ND-11, and it is expensive. Many horror stories of idiot shops and owners, using the wrong oil, or using equipment that was used on a traditional PAG based car.

An AC manifold gauge set.

Consider investing in the Toyota factory service manual. $15 for a two business day subscription.
Toyota - New Subscription
Why pay for the manual? The manual lists something called "specifications" that you should know, so you don't overcharge the AC system, which can lead to more problems down the road. It lso provides detailed repair procedures and trouble shooting guides. Chilton and Haynes manuals are junk, compared to the factory service manual. Knowledge is power, and this can't be stressed enough.

You can also convert the CHM service manual files to PDF files, for your permanent reference like this member did.
Toyota TIS download tips | PriusChat

 

I suspect you're talking about this one?

I see that HF even calls it suitable for A/C repair, even though it will only pull a 28.3 inch vacuum under the best of circumstances. (Did you notice you need a 4.2 CFM at 90 psi air compressor to power the thing?)

Nowhere else have I ever heard a 28.3 inch vacuum called adequate for A/C servicing. One of the specifications you can find in the repair manuals exstudent mentioned is the depth of vacuum you need. I'm looking in a Gen 1 manual for convenience, but there it says to pump to a 750 mm vacuum or better. In inches, that's better than 29.5.

Those measurements are relative to atmospheric pressure (normally about 760 mm of mercury), so a 750 mm vacuum is only 10 mmHg away from true vacuum. In fact, A/C techs sometimes measure vacuum in the other direction, with true vacuum as the reference point, and often in microns (a mm is 1000 of those). So Toyota is talking about evacuating the system to 10,000 microns or below.

Part of the purpose is, you can't have H₂O in there. If you do, it interferes with the refrigerant phase changes needed for A/C to work. In evacuating the system, you are pulling a vacuum deep enough to reduce water's boiling point below the surrounding temperature, so whatever is in there will vaporize and be sucked out.

At the recommended 10,000 micron vacuum, water boils around 53 F, so as long as you're in a decently warm shop, that's enough to do the job. But at 28.3 inches (41,000 microns away from true vacuum), water boils at closer to 92 F. Maybe you could make that work if you were doing the job on a hot summer day. You'd just have to make sure that all the little tubing bends and crannies, everywhere in the engine compartment and cabin and A/C enclosure, all were above that temperature. And you'd still end up with four times as much air in there as you should have.

Here's a link to some good info on the kind of equipment needed to achieve vacuum of the levels needed for A/C work. It's more than just sucking some air out. (A chart of vacuum levels to H₂O boiling points can be found on the next-to-last page.)

-Chap

edit: ... though on page 4 of the link, "bourdon tube gauge ... cannot read fractions" is a memorable piece of gobbledygook. :/