Pretty sure I have a leak in my 2007 AC because blowing warm air. I've watched many videos on recharging but all seem a little bit different from each other. Is there a best one to watch? For some reason I get sent to the youtubers whose camera skills give me vertigo tbh. - Some advice is that's common to "top it off" with refrigerant and others say don't do that? Which one. - If I use a R134a and leak detector/dye to recharge should the AC system be evacuated first? Is it necessary to attach a vacuum pump to a set of manifold gauges? I have seen both that its necessary and its not necessary - Where is the most likely place that a Prius AC may be leaking with 250K miles? - Are there any signs of leak locations PRIOR to testing it with dye? Either in the interior or in the engine compartment for Prius' specifically?
It's a variable pressure system so the people who refill based on pressure are at risk of causing damage... Seems the people who top off just a little don't have much problem. But its properly done by evacuating entire system and then putting in a specific weight of lubricant and specific weight of refrigerant.
isn't the ND oil lubricant only necessary if the compressor is affected? I can't remember someone mentioning adding lubricant otherwise.
I've not done this job before but I suspect there is more flexibility on being a bit off on lubricant compared to being off on refrigerant... Looks like prices are coming down on equipment though and a repair shop can get one with a library of settings for most vehicles for as low as $1K but most still selling for $4K. As for us shade tree mechanics lowest price point would be one of these and then putting your tank on a scale to measure it: https://www.vevor.com/s/3,4-HP-portable-recovery-AC
The AC system in the prius is pretty delicately balanced and wants a precise amount of refrigerant to deliver real results. Save topping off for the last summer trip before you sell/crush the car. If you're just trying to get it to leak so you can spot the leak, you probably don't need to pull a vacuum. Save that for after you've really fixed it and you're doing the real charge. Condenser. They take rock hits, people back into them, and sometimes they just corrode. Beware cheap aftermarket condensers; there are some really crummy counterfeits out there that cost little to buy but your system will have much less cooling capacity, especially on the hottest days. When the refrigerant leaks out it won't leave marks, but when it pushes the ND11 oil out with it that will leave a mark and the oily spot will attract dirt quickly. So you're looking for oily dirty spots on the AC plumbing. Remember, it's a finicky balance. You want to use a very accurate scale to weigh the refrigerant as you feed it in for the final fill- try to get within a few grams for full performance.
Thank you for the comprehensive reply. you bring up a great point. If a car has 250K.... what amount of diligence and dedication should you allocate to this job? this guy has a good channel, so hopefully this video might be helpful as I'm just starting to watch it....
While the condenser can be a leak spot and a leak there is relatively easy to see because of leaking refrigerant oil, the under dash evaporator is an even more common gen2 ac leak location. The evaporator leak is a major job so most people simply top it off on an old Prius. This is risky on a high voltage compressor. The whole system is less than one 16 oz can. Do not use r134a with sealers or refrigerant oil! The high voltage in the compressor can be shorted. Do not overcharge. Purge the line from the can to the fitting to eliminate air and then slowly add while watching the sight glass to clear. AC on. Do not overfill; stop when the bubbles clear.
this is another dilemma...I presume that the leak, however big or small, will be difficult to fix (for me at least as I have no-experience with these matters). if your car has 250K miles whats the problem with using the sealer/stop-leak? I'll probably be the last owner of this Prius. Like my other Prius'.
If your car is just suffering from a slow degradation of the AC system over a period of years, it's usually just due system seepage of a 19 year old system.. Use the above graph to add a bit of pure 134a. If it's really low, there may not even be the appearance of bubbles when the system is running, until after you add enough refrigerant to get adequate liquid in the system.
The problem is sealer can burn out the compressor. A top off will usually last a year per charge. If not it will be empty in a week and will need a repair, typically a condenser or evaporator.
The leak in our evaporator wasn't slow. Just before we had that part replaced in a week it would lose enough refrigerant to stop working. Not wanting to burn out the compressor we stopped using the A/C as soon as the it showed signs of failing.
is it pretty much always the evaporator? I've visually looked up and down for a potential problem area and can't find one. I have a feeling its the evaporator as well. Gonna try to do a leak test over the weekend to find out for sure.
If it is the evaporator you might look to see if any of your leaktest dye has come out the evaporator drain tube- the one that normally dribbles water out. That's next to the front right footwell, under the car. System sealer is bad a few ways around. Again, the system is very carefully balanced, built to use the minimum amount of refrigerant to deliver performance through the normal service life of the car. Changing the interior volume of the system (space taken up by sealers) is going to upset that balance. The sealers can possibly have chemical reactions with the (different from most cars) ND11 oil. And lastly there can be electrical reactions with the electric compressor. The bad news is that with a finicky system like that, the way to make it work at all is to make it work right, and that can be a big bill on an old car.
