Just purchased car and A/C air not cold :(

Finding a note that dye was applied means that somebody suspected a leak in the system.

Not finding a later note that a leaky part was replaced suggests that if it was ever found, it might not have been fixed.

You may have just discovered why the car was for sale.

I would start by looking for dye stains, in the hopes of locating the leak.

The thing to know here is that a Prius is very sensitive to refrigerant quantity. If you are off by much in either direction, there will be expensive consequences, unfortunately. Many have learned this the hard way.

If you don't know how much refrigerant is in the system, the only way to gain certainty is to recover and vacuum out all that remains and start over from zero.

Don't get suckered in by the quick-shot storebought cans. Those are for cars you're going to get rid of this week.

 

If you connect a low side gauge to the system use of that goes from zero to a hundred pounds with a blue hose on it what does it say right now not on sitting . Nothing at all on You see like 90 lb on the gauge? I'm also not certain that our specialized oil for the electric compressor comes premixed with dye I haven't gone shopping for this yet so I don't know if they use the proper oil and then injected the die separately or whether they make our oil with dye aalready in it I personally haven't looked. And looking for long streaks of this die on every fitting you can see condenser compressor hoses so on and so forth connections at the fire wall.

 

If you have one of those silly cans of 134a with the gauge on it that you used to charge the wife's car or your other car or what have you connect that to the fitting that's in between the inverter and the engine with the gray cap on it might be a black cat that fitting will only fit on that tube It won't fit on the one on the other side of the engine when you do that with the system not running nothing's happening no buttons have been pushed what is the gauge say? That's a quick test you should be able to do in the advance Auto parking lot You're looking for right around 88 to 94 some odd pounds at rest seriously. If you see 40 you are extremely low on gas 40s what it needs to be at or close to it when the system is running compressor pumping everything on that line is cold so on and so forth.

 

If it's a bad leak you can usually spot it as a big oily wet spot, even without dye. You still sort of need to know where to look.

For slower leaks and harder-to-reach areas, you need the dye and then an ultraviolet lamp to make the dye light up- but you still need to know more or less where to check.

A leaky condenser is common on cars that old, and not that bad for repair costs. A leaky evaporator is a bit less likely but they require an obnoxious amount of labor to swap... so hope it isn't that.

 

To see refrigerant dye you need a uv light and glasses. As stated above the most common leaks are in the condenser (in front of radiator) and the evaporator (buried behind dash which has to come out to change). The evaporator is close to $2000 installed due to labor and parts. In either case use only oem parts or you will lose cooling capacity. Never use sealer or refrigerant with sealer or oil. High voltage 3 phase power is in the compressor which can burn out with the wrong oil.

 

The glasses help.

 

My UV black light that is just a handheld fluorescent piece of nonsense and I also have one that's made by Coast like a flashlight I haven't never had to use the glasses I just use the little flashlight put it in the right mode and I'm usually doing this at dusk or I'm pushed in the garage which is like dusk in the shade and then that's droplets of that yellow dye light up like fluorescent man It's like a light show from the '60s if it's coming out like that and if it's in the evaporator I just test the water as it's dripping out if the system's running at all If not you can just pour water into the evaporator case and what runs back out shine the light on that see traces of the dye and you know you haven't evap leak or expansion valve or something like that in that case.

 

The glasses are to protect your retinas, not to make the image clearer. Always wear eye protection when working with UV!

Personally, I would take this car to an A/C shop and not turn on the A/C until then. For all you know the amount of refrigerant is way off and running it like that can destroy the compressor.

 

the only way to get one of those systems working right is to put exactly the right amount of refrigerant in.

That means recovering whatever's in there, vacuuming the system totally empty, and then adding back exactly the right amount as measured by a scale.

if you're off by much, it'll wear out the compressor pretty quickly.

 

So this picture of the gauge this is with the car on and the air conditioning on a full tilt correct?

If that's your standing pressure with the car off then sitting there 20 minutes whatever You should see almost 100 lb on your gauge 94 something not 37

 

Yeah generally on all of my cars here including my '01 sienna van when the system is completely stopped there's no high and low side both the high and low side with the appropriate gauge and the proper fitting to connect it to the hose will read right at 100 lb 94 96 93 Right in there somewhere The minute you turn on the air conditioning switch you will see the low side which is the side you're dealing with get pulled down to that 37 or so that you see right now which I guess you have because you're pretty low on gas that should be enough to start the system and the compressors running but it's Wailing out RPM tryna pump al.ost nothing. Don't do that get a can of gas turn the mess on can upside down and start letting some in slowly and feel your fat hose coming off the compressor. When it starts getting cold you need to keep an eye on your sight glass and almost all the bubbles start to clear turn off the gas feed and let it sit there and run and watch the bubbles or lack thereof in the sight glass and feel your big line should be nice and refrigerator cold air conditioner should be on LO and high fan The car should be cooling off smartly inside by now You should be seeing a constant 37 on the low side gauge or somewhere right around there up to 42. And that should be about it pretty uneventful.

 

I wouldn't do that.

Well, it's nothing if you don't count the $2000+ you'll spend replacing the destroyed compressor.

 

The metal lines unless they're rubbing against something what you see on those is should be just residual where somebody touched some blow-by got loose and stuck to the pipe where it turns to rubber and where connections are like penetrating the firewall and the o-rings If you get one of these cars and it's already out of gas before you go shooting gas in it you might want to put a few o-rings in they're easy to put in it doesn't take much to do it and many times they are old deteriorating and will let gas by them so you buy an o-ring kit they're like green color or purple the o-rings they're better than Buna N which was the old type. Then you can shoot some gas in get enough pressure to kick the compressor on look at your sight glass run it up until the bubbles almost disappear stop charging see the 37 or so on the low side pretty consistent have a fat cold metal line and car cooling and call it a day and see what happens next year or at the end of cooling season Is everything still working? You're probably good $2,000 compressor not in my world I'm at five of them sitting here in the shed ready to go they're very reliable It's only when you run them low on gas and have them winding out at 7,000 RPMs are they going to think about imploding and shredding themselves generally speaking of course.