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Help with AC Please. 2009 Prius. Blowing not cold air.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by SunMan, Aug 28, 2019.

  1. SunMan

    SunMan Junior Member

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    Sometime ago I used to own a restaurant, and had plenty of CO2. But do not know anyone anymore.
     
  2. lech auto air conditionin

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    Stay away from CO2 that is what’s considered a dirty wet gas the last thing you would want to use next to using wet shop compressed air.
    The other problem is CO2 gas it expands and contracts too much to do a reliable or any kind of field overnight pressure testing . It’s like refrigerant as the temperature goes up on the gas the pressure goes up when the temperature goes down the pressure goes down you would not know if you had a leak .

    Nitrogen at our atmosphere pressure and at the temperatures that as humans existing is not affected by rising and falling pressures in a small system with a small temperature swings that are human bodies exist that.
    The kind of leaks were are looking for are the ones what will cause you aggravation over a period of weeks or months.
    The big leaks that most people are thinking about can easily be found the backyard do it yourself mechanic way add some refrigerant to the system and start squirting everything down with soapy water at all your fittings and joints.
    The problem with refrigerant is that the pressure can only get as high as the ambient temperature example. If I put 1 ounce or 10 ounces of refrigerant into your system and it was 70° outside the pressure cannot exceed 70 psi .
    Now if I magically picked up that car that I just put refrigerant and dropped it into the middle of the Arizona desert on a stretch of blacktop on 115° day. That very same few ounces of refrigerant would expand and increase in pressure up to 158 psi because all the hoses and pipes condenser and evaporator and compressor would all be the same temperature 115°F .
    Now think of the scenario we have our gauges hooked up whether this was refrigerant CO2 does The same thing but at a different rate. We have a gauge is hooked up and we’re going to let it sit overnight to test if we have a leak. Now that we’re in this desert and we know some deserts could get nearly freezing cold at night in the other extreme we come out to our car in the morning and it’s 40° outside. You look at your gauges sitting on your car hooked up to your air conditioning system and it reads 35 psi. Wow we have a big leak. No the gas has just contracted condensed down to that pressure when it gets that cold.

    This is why you use inert noble gases that are nearly rocksteady within a wide temperature band that we live on this planet earth nitrogen is barely affected.

    The kind a leak that we look for that will aggravate you and cause your system to lose refrigerant over a period of weeks or months causing your compressor to overheat but still give you some cooling and shorten your compressor life you cannot possibly see using a set of analog gauges finding leaks using pressure drop using analog gauges is only for a very large huge leaks that are easily found.

    When there’s a lot of dollars at stake because you have $1000 or $2500 AC compressor on the line that you may lose or you were just doing a Mercedes-Benz that took 21 hours of labor to get to the evaporator and before you put that dash back together do you wanna really make sure it’s not leaking so you don’t have to rip it all apart again and do it a second time for free. when there’s a lot of dollars at stake because you have $1000 or $2500 AC compressor on the line that you may lose or you were just doing a Mercedes-Benz that took 21 hours of labor @ $180 a hr, to get to the evaporator and before you put that dash back together do you wanna really make sure it’s not leaking so you don’t have to rip it all apart again and do it a second time for free. So you could perform a vacuum decay leak test which is the least reliable using a micron meter overnight which reads vacuum leakage down to the thousands of a psi that could not possibly be seen or even move a analog needle. And the problem with vacuum testing is the pressure difference between atmospheric pressure in a vacuum is only 14.7 psi.

    Then we perform a high-pressure dry nitrogen decay test. Add 150 psi only with a very precise pressure gauge that is accurate within the 10th of a psi and is not affected by temperature swings that most gauges and digital gauges are affected by throwing their calibration off giving you a false reading. And the gauges are barometric compensated they actually read the outside barometric pressure so if one day is clear and sunny and then a storm front comes in a high-pressure or low-pressure will actually affect your readings a good set of micron gauges will compensate for this and give you a true reading.

    This is why if somebody went out and just bought any old plain micron gauge or pressure gauge and they don’t even know what its limitations are and don’t understand the specifications they’ll be running in circles chasing their tail looking for a leak that is not even there or saying that the gauges don’t work and they don’t understand why they’re seeing the numbers that are changing in front of them that do not make sense.

    When buying these types of tools you cannot believe advertisement you cannot believe the salesman you cannot believe the marketing team most of the time especially in the automotive industry that’s considered bottom end feeders. That are easy for salesman to convince to buy tools that are not even qualified for the job they’re doing but because their flashlights and make a beeping sound sold by big companies and have glossy colored fancy literature with a lot of technical terms and certificates of calibration means that tool must be good.
     
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  3. SunMan

    SunMan Junior Member

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    Will do. Don't have access to it anyway. Thanks for the education.
     
  4. SunMan

    SunMan Junior Member

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    Well the day came. Yesterday replaced the compressor, pulled 6 hour vac. No leak. Added 3.75 oz of hybrid oil. This morning did another hour of vac. About 2:15 pm 90 f temp, started to charge the system with the 1st 12 oz can of r134a Its been hour and half and the 1st can is still not empty. When I shake it I can hear the liquid inside. The manifold gauge showed 50 psi the 1st minute and very slowly going up. Hour and half later it only went up to 75 psi. Can someone shed a light on this. Is this normal behavior? I feel like I am back at the beginning where it was not accepting charge. Can I charge thru the high side to speed up the process, but I think it might not make a difference.

    If it is normal, how long would it take to charge the 16 oz?

    A quick reply would be greatly appreciated, since I am in the middle of the re-charge right now.
     
  5. Aegean

    Aegean Active Member

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    I would switch to the second 12oz can. there always will be some left on the first can. I believe this is because now the pressure you have in the system is close to the pressure on the can. If you weighted before and after you will know how much went in. If not weight the second one and assume both had the same weight gross. Then weight the half empty first can to find out how much went in the system already. Do the same with second can later.
     
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  6. SunMan

    SunMan Junior Member

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    Thanks for the quick reply. OK, good to know. The only problem is I did not weigh the 1st, thinking that all of it would go in and I'll just weight the 2nd can befo-n-afta. And the 2nd is not new. I'll just run to the wally world to get a fresh can and continue. Will update.
     
  7. Skibob

    Skibob Senior Member

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    I have always had problems getting the can to empty. It gets cold and just evens out on pressure. Easiest way I have ever found is to put it where it’s hot, like next to the radiator on my 4 runner. Never charged my Prius so I don’t know where it gets hot under the hood
     
  8. SunMan

    SunMan Junior Member

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    And also, when I was hooking the new 1st can, it accidently leaked for maybe 3 seconds. I wonder how leaked out
     
  9. SunMan

    SunMan Junior Member

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    Its not frozen just barely cold because I can hear the liquid on shaking. Besides I had them in sun for a while, and I wrapped towel around it.
     
  10. Skibob

    Skibob Senior Member

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    Wrapping a towel around it insulates the can from warming up. The can get really cold when it starts filling up the system.
    Heat, heat, heat.
     
  11. SunMan

    SunMan Junior Member

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    Well, got 2 can just in case. Full can weighs 15.5 oz so the can weight would be 3.5 oz. That means I have put in about 7.1 oz - what I lost in that accidental leak. I have put in the 2nd can. I will weight it in a few minutes to see how much went in. But I was watching Lech's video and it took him maybe 15 seconds to put in 15 oz. That kinda makes think that what is going on wit my system.
     
  12. SunMan

    SunMan Junior Member

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    Half an hour later about half an ounce went in. I removed the towel. The can is not super cold but not warm either. I am afraid to turn the ac for just a few seconds to see if makes any difference. I am not sure what to do at this point other than just wait.
     
  13. SunMan

    SunMan Junior Member

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    And btw, the gauge has slowly moved up to a little over 90 psi.
     
  14. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I think you should see if the AC compressor will run now.
     
  15. SunMan

    SunMan Junior Member

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    I wanted someone to agree with that idea. I just tried but the compressor wants to turn on but makes the clicking sound for a few seconds and then turns off and does the same thing over again. I turned it off. I wonder if I should try to bypass the pressure switch.
     
  16. Patrick Wong

    Patrick Wong DIY Enthusiast

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    1. This is my understanding of the work you have done so far: You replaced the compressor, condenser, dryer.
    2. You did not replace the inverter.
    3. The system behaves the same as in your post 1.
    4. What DTC is logged now?
    5. It is possible that the inverter still needs to be replaced.
     
  17. SunMan

    SunMan Junior Member

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    It just blows my mind thinking that why can I not charge 16 oz of refrigerant, regardless of which part is bad. Whether it is compressor or inverter. There can't be a blockage issue either because I am able to put in 8.5 oz. Now I have new compressor, condenser, o-rings, and schrader valves. It compels me to think that I still have the original issue, because the the compressor is making the same clicking sound that the 1st compressor made. Do you think the inverter is not sending enough voltage and/or amperage that is needed to run the compressor, which you suggested in the 1st place?
     
  18. SunMan

    SunMan Junior Member

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    I just replied to your post thinking the same exact thing. That should have been or should be the course. Is there any way to test the voltage and the power the inverter is sending. If the new inverter fixes the problem. Then it would prove that my original compressor was good and turning off and on several time probably killed the compressor. O man what a lesson would that be.
     
  19. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I don't know, see if you can retrieve any DTC related to the air conditioning system.

    Well, you would have to expose the three-phase AC wiring from the inverter to the AC compressor. If you could do that safely while bypassing any interlocks, then you could measure the AC voltage.

    To measure the current you could use a clamp multimeter to measure the current in one wire. That is a specialty meter which most hobbyists have not invested in. This is what I use:
    Fluke 365 Detachable Jaw True RMS AC/DC Clamp Meter | Fluke
     
    #79 Patrick Wong, Oct 4, 2019
    Last edited: Oct 4, 2019
  20. Skibob

    Skibob Senior Member

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    Generally you have the compressor running to have the low side low enough to suck the Freon in. If the compressor is not on all you can do is reach equilibrium with the can.