Air conditioning not blowing cold air...

You also have to pull a vacuum on the a/c system, and it has to hold the vacuum, before you can charge the system.

 

Not just a vacuum but 500 microns or below. You can not even see or read that on a normal set of gauges. Vacuum tells you nothing about a leak unless it super big. It can hold vacuum but leak under pressure. the difference between 30in , 1bar vacuum and atmosphere is only 14.69 psi or 1 bar. The differences between a working system with a full refrigerant charge on a hot day 100F or 37.7 C could be 250 PSI+ or 17.23 Bar.

This Denso compressor should last the life of the car if it is never allowed to run low on refrigerant, someone dose not over charge it, tries to top it off ( stupid! ), drive too much refrigerant down the low side with the compressor running flushing out the oil or liquid slugging the compressor, and many other things that can shorten the life of the compressor. I see many prius bad compressors every week, 99% die because the owner let the ac system refrigerant run low and the other is the shop or person who TRIED to recharge or fix it. It works good for a time but then the compressor fails later.

PS, go look at photos on my page of prius compressors burnouts, I could spend every week dissembling prius compressors because someone DID NOT FALLOW THE RULES OF A/C !!! This is not grandpa's old Chevy any more.

 

Thanks for the helpful albums Lech. I encourage others to have a look at his A/C 101. Daunting for DIY's, as the cost of the modern equipment to do the work correctly is very high.

In the Prius A/C system, what are the spots that you see with the highest tendency to leak?

 

Won't the system sense a low refridgerant charge and not cycle the compressor? Gramps ol' chevy would do that.

 

Even a few Oz/ml. will run fine on cooler days but when the outside temp goes up there is is no more refrigerant to flow when the expansion valve opens up to allow more there is no more. So the gas flashes off no more to do work to remove heat. There was always extra refrigerant in the system to return a cool refrigerant flow back to the electric compressor motor winding to cool them, and to return the oil that was carried out of the compressor. when the refrigerant gets too low the oil start to gather in the bottom of the evaporator. Not returning back to the compressor at the same time the compressor is getting hotter because it is not getting cool refrigerant back to itself " that extra oil would be nice to have now when the compressor is winding up to 8000 RPMs. All this was figured out before we were all born when the first electric compressors were used in commercial residential ac and refrigeration. Automotive is a little slow to catch on and tries to reinvent the wheel. All the old auto a/c text books need to be thrown out and the old mechanics to who cant catch up, or are to lazy or cheep.
The new tools are vary expensive , time consuming to learn, the cheep tools just barley work or beak or give bad information. THIS MEANS THE CUSTOMER WILL PAY FOR FALSE DIAGNOSTICS!!!!! AND REPLACE PARTS NOT NEEDED OR NOT REPLACE PARTS THAT ARE NEEDED!!!. The consumer loses....

PS. no the computer or sensors do not turn off the ac if its a little low.

 

Hello ,i have a question for anyone here.... we ran our '06 Prius for a few months with a failing coolant control valve. Then all of a sudden, the a/c doesnt blow at all. I just replaced the valve myself, as well as drained out about 1.2 gallons of coolant, and replaced with new coolant (the extreme expensive stuff of course !) could i have damaged anything by running the car with a bad coolant valve ? the a/c did work great for a long time... im worried i damaged the compressor . any thoughts ? thanks

 

the a/c does not blow COLD at all.. it still blows good through the vents sorry for the confusion

 

I am curious - when can you tell if the AC refrigerant in a Prius Gen II is running out? I had my vehicle serviced late last year by Toyota - it was the 60,000 mile service (though it did turn out later that it had had a prior 60,000 mile service at 54,000 miles by the previous owner). Am I safe in assuming that Toyota would definitely include checking the AC's operational status (including refrigerant levels) as part of the service?

I shudder at the thought of me possibly driving around, unknowingly running the AC with critically low levels of Refrigerant.


iPad ? HD

 

I don't believe the ac is serviced unless there is trouble reported.

SM-N900P ?

 

Lech, please clarify your warning about top offs. My 2007 Prius AC stops blowing cold after about 2 hrs. in 90-plus FL summer weather. Cool will return if car shut off for about 1/2 hour. Seems like low freon to me. What to do? Will search for your page.

 

While my 2008 T Spirit Prius A/C seems to have been working perfectly since I bought the vehicle in June 2013, I have noticed that when the A/C compressor is running, one can hear a barely audible short lived "Bark" repeatedly emanating from the front of the car. This only occurs during A/C operation. It has also been reported by many other puzzled Prii Gen II owners. Does anyone on this thread know what that sound is, and whether it is indicative of some problem - such as low refrigerant or inadequate oil in the compressor system.....? I'm just curious.

 

on most a/c systems, you recover the r134 and then evacuate and recharge the system. most shops will mix some UV dye into the oil and inject an ounce or 2 of dyed oil into the system. that way, its easy to find the leak, and there's no danger of overcharging. many times the leak is so small it won't be noticeable until next summer when you try to use the a/c again. most likely there will be green slime or at least a stain at the leak. I don't know if this works on a prius though.

if you try to just top it off, and the problem isn't low refrigerant, you will overcharge and most likely damage the system.

 

My problem is somewhat different. The 2007 Prius AC works fine at first. After about 2 hours there is no more cold air at 77-degree setting. Lowering the thermostat to the lowest temp or increasing fan speed doesn't help. Sometimes stopping the car for about 1/2 hour helps reset the system. There are no strange noises. This happens in 90+ degree weather. Not a problem now when the weather is in the low 70s. Using AC mainly as a dehumidifier. (This is FL.) R134 level and compressor don't seem to be an issue. Could there be ice forming? Would like to avoid dealership service department's high prices.

 

In very humid conditions, some home AC units have this problem. The humidity forms on the freon/ac lines and freezes. By turning it off for 1/2 hour, it will defrost itself and work normally again.

Personally I've never had this happen in a car but had this happen at home in Las Vegas during humid and hot weather.

 

Hi John,
Just wondering if you published a post on your DIY compressor change in the UK? I haven;t been abl;e to find anything?

I believe I have a failed AC compressor (loud whine, some crunching noises, now stopped) system fully gassed up but definately not blowing cold and no activity at all in the sight glass.

I've also got a UK Prius & am struggling a bit with finding some R134a with no oil, dye or leak stop in it & am just wondering what you used & where you got it from? I like the suggestion of pipe freeze R134a - very clever. Do you have a recommendation for ND-11 oil?

Any advice on what to use & where to get it from greatly received.

Thanks in advance

Matt

 

Matt. I used plumbers pipe freeze spray available from B&Q or building supply merchants. This is pure R134A . You can make up a simple filling adapter by drilling a small hole in a low pressure line cap from a breakers. The hole should be small enough so that the plastic tube that comes with the can of freezer is a tight fit or so that you can glue it in.
I have not found a source of ND11 oil in the UK as yet.

John

 

Thanks John - very helpful.

 

The best value I found was from B&Q and a product from "Rothenberger".

John

 

Hello everyone i am facing problem with my prius AC i replaced condenser and compressor as well also get checked the lines for leakage but all in vein it is not blowing the cold air the air is a little cold not as colder as it was before ! Please help i have a 2007 toyota prius japneese model G touring selection.

 

hard to say without diagnosis. how do you know if the compressor is working properly?