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AC system maintenance / repair / recharge

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by prmp945, Jun 27, 2023.

  1. prmp945

    prmp945 Member

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    Hello all,

    I own a 2011 Prius and the AC is barely blowing cold. A couple of weeks ago, when the ambient temperature was about 80F and the car in the shade, I measured the following temperatures from left vent (driver) to right vent (passenger):

    62 58 78 88

    In other words, the driver is still getting some cool air, but the passenger is not.

    After reading through lots of posts and watching lots of videos by @lech auto air conditionin - I believe problem is simply that the car is low on refrigerant after 12 years of faithful service.

    I want to attempt fixing this myself. Not so much to save money as to learn and be independent. I also hate the dealership.

    Here is my plan:

    1. Purchase uvBeast V3 mini 365nm flashlight
    2. Inspect system for physical damage
    3. Inspect schrader valves for leaks with soapy water
    4. Inspect system for leaks with the UV flashlight
    5. If a difficult leak source is detected, re-evaluate plan. If only simple leaks (seals?) are detected, then purchase necessary parts.
    6. If no major leak is detected, purchase the following parts:
    7. Bring car to a shop to evacuate the current R134A
    8. Replace the condenser & use nylog blue on new seals
    9. Pull vacuum
    10. Add 470g of R134A
    11. Chill & enjoy

    How does this plan sound?

    You will notice that the first part in the above list is a new OEM condenser with drier filter. It seems like it would be a good idea to replace this part while I'm doing the evacuation & recharge because even if it doesn't currently have a leak, it has experienced 12 years of wear & tear. Also, I've read that replacing the drier filter (included with the condenser) every 5 years is good practice. Good idea? Also, if I replace the condenser, should I add new Toyota OEM ND11 oil? If so, how much?

    Thanks for reading!
     
    #1 prmp945, Jun 27, 2023
    Last edited: Jun 27, 2023
  2. Mendel Leisk

    Mendel Leisk Senior Member

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    I was in a similar situation a few years back, had our dealership do an AC inspection and recharge, was around $165 CDN. That was about 4 years back, still working good.
     
  3. Tombukt2

    Tombukt2 Senior Member

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    Sounds like a plan It's getting hot
     
  4. ASRDogman

    ASRDogman Senior Member

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    If you search on here, there is a motor for a vent door. Seems like it might
    not be working or allowing it to block the vent, allowing some hot air to pass.
    You should check that.

    Why do you feel you need to replace the condensor? Is it damages or leaking?
    It doesn't really wear out.

    Have you sprayed water from the engine side to the front to get all the dirt and bugs out?

    "If" it's low on freon, there IS a leak. It is a sealed system. You "may" just need to replace
    all the "O" rings, evac and recharge.

    You should put the gauges on it and get readings. Somewhere there is a chart that will
    tell you what they should be under each conditions, temperature, humidity, etc.

    Kind of a waste of money to just start replacing parts....

     
  5. prmp945

    prmp945 Member

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    In my initial searching I assumed it was a vent door, but my search results did not find anything that matched up with my problem.

    In contrast, I did find this post by the resident AC expert @lech auto air conditionin - where he describes why low refrigerant can result in only some vents blowing cold:

    A/C cold only on passenger side; barely cool on driver's side | PriusChat

    I agree that it might seem unnecessary to replace the condenser. However, I can see some minor damage to the fins on the condenser, although I don't have my UV flashlight yet to try and detect any leaks. Regardless, if it has some visible physical damage, it might not be a bad idea to replace it (and the associated o-rings) while I have the system evacuated. Additionally, some mechanics strongly recommend replacing the drier filter (which is part of the OEM condenser) any time the AC system is evacuated. I'm curious what @lech auto air conditionin thinks about that.
     
  6. lech auto air conditionin

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    Sounds like one of the best plans I’ve heard heard anybody mention right off the bat first time.

    You could save 8% off the price of those NAVAC gauges and hoses and the NYLOG over on True Tech Tools website.
    You use my promo code that get you 8% off and to check out discount coupon box
    LECHAIR all one word all capital letters.
    And since it’s over $50 in components, shipping is free.
     
  7. prmp945

    prmp945 Member

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    Lech, thanks for the comments and promo code!

    Would you mind giving your thoughts on the last paragraph of the OP (copied below)?

    You will notice that the first part in the above list is a new OEM condenser with drier filter. It seems like it would be a good idea to replace this part while I'm doing the evacuation & recharge because even if it doesn't currently have a leak, it has experienced 12 years of wear & tear. Also, I've read that replacing the drier filter (included with the condenser) every 5 years is good practice. Good idea? Also, if I replace the condenser, should I add new Toyota OEM ND11 oil? If so, how much?
     
  8. prmp945

    prmp945 Member

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    I received the uvBeast flashlight and could not detect any leaks.That may be a good thing, but does the 3rd gen Prius come from the factory with a UV dye? The factory sticker doesn't say. Maybe I am not finding any leaks because Toyota does not include dye from the factory.

    My GMC truck's sticker does say that it comes with dye from the factory (and I can detect some on the schrader valves).

    IMG_3990_(Small).jpeg

    IMG_4024_(Small).jpeg
     
    #8 prmp945, Jul 1, 2023
    Last edited: Jul 1, 2023
  9. lech auto air conditionin

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    you need to add dye?
     
  10. ASRDogman

    ASRDogman Senior Member

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    It doesn't detect it because it is not there....
    The dye is nasty..... It's best not to use it. But some will cry that it won't harm
    the system.....
    There is NO reason any auto manufacturer would want to or need to add the dye.
    Dealerships have the correct "sniffer" to dectect the leak.

     
  11. TMR-JWAP

    TMR-JWAP Senior Member

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    A lot of work for what a single $10 can of R134a could solve.....
     
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  12. lech auto air conditionin

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    Actually, many of the car dealerships, don’t maintenance the refrigerant leak detectors for years some even decades.

    And none of them on lab grade, refrigerant leak detection, reference bottles to calibrate and test their refrigerant leak detectors like I do.

    tracerLine UV dye is the one die most all manufactures use and recommend in their OEM applications.
    Extremely highly concentrated, nothing like the old days I would have solvent in them or other oils, and would take 1 ounce.

    The new generation of dyes are extremely concentrated just 5 mL is enough up to 14 ounces of oil capacity.

    In a little Prius that only has roughly a Hair over 3 ounces of oil capacity you basically only need one to 2 mL that you can almost not measure. This is how concentrated this dye is.

    other methods are using a Ultrasonic leak detector either under vacuum, which is a poor method of looking for a leak or using 200 psi of dry nitrogen.

    Most cheaper leak detectors under the $300 range lose their sensitivity quickly over a period of time to find extremely small leaks. And unfortunately when one shop refrigerant leak detectors use between many technicians. Sometimes they accidentally stick the tip in condensate water and suck water up and contaminate the sensor and they never know it.. so they look for leaks that they can’t fine because they’re using a refrigerant leak detector. That is no longer sensitive..

    Real good refrigerant leak detectors start at somewhere around $500 and up.

    No one single method always works all the time at the time of testing. Because sometimes leaks or dependent on a certain pressure range before they start leaking and then when you pull into your stall and you stop the pressure lowers and the leak stops.

    Some leaks only happens when the car is going down the road and hoses in lines are vibrating from the rough road. But when you stop and you’re still with the hood up in the garage, the leak stops.

    Some leaks only leak at a certain temperature. When the temperature rises, then it starts leaking some leak only when the low side gets cold aluminum contracts and shrinks, and then it leaks but when you turn it off in the middle gets warm, it expands, and the leak stops.

    this is why if you have UV dye in the system days or weeks or even a month when that leak starts sometimes but not always it’ll leave a trace of dye at the lesk point

    Not all leaks leave a refrigerant oil spot .
     
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  13. prmp945

    prmp945 Member

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    Lech: what is the best way for a DIYer to add 1-2ml of dye to the system so that I can check for leaks before evacuating and refilling?

    I saw the method that you showed in this video, but I don't think this will work if I only want to add only 1-2ml of dye, without any oil:


    The tools sold for this purpose do not appear precise enough to deliver just 1-2ml of dye. For example, this one has 7.5ml gradations:
    Lichamp Dye Injector Kit
     
  14. lech auto air conditionin

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    unfortunately, it’s going to be expensive because you will have to purchase a tracer line die injector tool for their EV only cartridges

    Because you only need a small quantity once you are not a shop, so you do not need a large volume and you do not need many applications

    tracerLine Products has little capsules with UV in it that are 0.03 ounce application dispensary capsules for electric compressors.

    go to TracerLine Products website you can look them up and find the part number
     
  15. prmp945

    prmp945 Member

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    Thanks again, Lech.

    As a less expensive alternative to using the professional TracerLine products, what about using one of the R134A cans that contains refrigerant and UV dye (but NO sealers, conditioners, or other magic formulas)?

    Johnsen's 6313 R134a Refrigerant w/UV Dye

    I could evacuate, pull a vacuum, and refill with a R134A & dye and then inspect for leaks with the UV flashlight. Then decide if I need to replace any parts.
     
  16. lech auto air conditionin

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    Yes, that is a good alternative.
     
  17. prmp945

    prmp945 Member

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    I found a manufacturer that makes a can that contains 1 oz UV dye and just 2 oz of R-134A instead of a full can (12 oz) of R-134A:

    FJC 4921 DyeCharge

    The very small amount of refrigerant in this can means I'll be able to add the dye/refrigerant before having the system evacuated without fear of overcharging. Then I'll inspect for leaks, then evacuate, then do a measured fill with pure R-134A.

    If I understand correctly, the UV dye will mix with the refrigerant oil already in the system, meaning that I will not lose the dye/oil mixture when I have the old refrigerant evacuated. So the system should retain the UV dye even after I do the measured fill with new refrigerant and I will be able to inspect for leaks in the future.
     
  18. prmp945

    prmp945 Member

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    I received the FJC 4921 DyeCharge in the mail today and put it in the low-pressure service port. I had the AC on high and the compressor was whining pretty loud. I did my best to purge the FJC 6045 Hose before connecting it, but this was likely not a perfect job.

    I measured the two driver-side vents blowing 57F with an ambient temperature of 85F. I was surprised that while adding the refrigerant/dye that the whine ramped down considerably. I measured the driver-side vents again and they had dropped from 57F to 46F. Moreover, the passenger-side vents previously were blowing ambient temp (85F) but were now blowing 51F.

    I'm surprised that adding just 1 oz of refrigerant (28g) had such a pronounced effect. The variable-speed compressors found in the Prius are definitely very sensitive to refrigerant charge!

    The dye seems to glow very bright with the uvBeast mini 365nm flashlight that I purchased previously. I did not see any leaks during my brief inspection tonight. I'll drive the car for the next couple of days with the AC on and then inspect for leaks again. If I don't find any leaks then I'll move on to evacuating and a measured refill with pure R-134A.
     
  19. lech auto air conditionin

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    You’re learning

    But be careful and don’t learn the expensive way.

    You are correct in your observation Prius and many other small capacity vehicles, the smaller the capacity, the more sensitive they are to 28 g

    The Prius and many other, and actually most use critically charged microchannel, condensers, and Evaporators

    1 ounce or 28 g has a very great effect on the operation of the Prius

    This all depends on ambient temperature and sun load

    I have a video posted showing a Prius that the very instant you hear the compressor engage the high side pressure immediately hit 440+ psi, engaging to protection, and immediately disengaging the compressor.

    In the video through my manifold gauges, I open up the service valves and remove 1 ounce, 28 g of refrigerant on the next compressor engagement. The compressor stayed running but it was somewhere around 350 to 370 psi. This was on a cool day..

    I opened up the Refrigerant Valve manifold to another hose with the equivalent length of 1 ounce of liquid refrigerant removal.
    And I think at this point the pressure dropped below 300 psi. The vehicle started cooling even though this refrigerant levels were still way too high and the compressor stayed spinning..

    At this point, you can still damage the compressor because it’s so overcharged later on it would burn out. But at this point the technician or the do it yourself person who is just using the low side port maybe would think it was done correctly because the compressor would still be spinning. The dash would still be getting cold air coming out of it, but the compressor would eventually fail.. Guessing is not good

    On the contrary, the other way around on a cool Ambien today.
    I have videos of Prius compressors operating system, where the refrigerant level was nearly halfway empty. I had a clear sight glass filled with Refrigerant.. coming out 39°F out of the dash and if this was a Car in Garage in the, Technician was shaking the cans adding by guessing or a do it yourself person. They would think that 39°F out the dash in a clear sight glass means the system is full and good to go. ?. BUT ITS NOT !

    What would happen as you the customer who just paid a fake hack shop who guesses by topping off refrigerant because they go by pressures and clear sight, glass, and temperature out the dash as their method of correct charge.

    You the customer would drive away and then on the next hot day when it hit 85°F
    Because of the sensors in the system would indicate that the AC system is not keeping up to your desired temperature you have set on your dash and it will start over spinning the compressor at 6000 or 7000 RPMs because the refrigerant is low because it was charged by Guessing on a cool day.
    And up to a certain temperature, it will keep you happy, thinking that everything is just fine and dandy. At the meantime the compressor is not getting enough refrigerant back to it to cool it off and the oil stops being re-delivered to the compressor. The refrigerant is an excellent solvent. It carries the refrigerant out of the compressor but let’s say only 90% or 80% returns. .
    And this action continues as the day gets hotter. Let’s say now 90°F as a customer you are not happy so you turn the air conditioning all the way down to minimum temperature..

    So now the car’s computer keeps it’s pending at 7000 RPMs starving for a cold refrigerant back to the compressor and even more oil start staying back up in the evaporator loading and filling up the Evaporator with the remaining oil from the compressor until it burns out.

    Guessing technicians who filled Prius, high temperatures and pressures in a clear sight, glass are often the main cause of compressor is burning out.

    There is only one 100% sure way to properly keep the three phase high-voltage electric compressors alive where they will outlast the life of your engine and transmission.

    That is still never allow them to go low on refrigerant in the first place. Always keep them 100% filled..

    And as long as no other outside exterior force, or anything else causes the compressor to go bad, because compressors do not die they are murdered

    Most all compressors will always outlast the life and the entire vehicle outlasted engines out last the Transmission’s.

    Compressors only die, because of neglect, or some outside source force that is the root cause of the compressor failure

    A compressor failure is a symptom of a problem. It is not the problem..

    And usually the technicians who are the old-school whack off the cans shaky cans of guys with the hairy palms and go blind are the ones responsible for all the compressor failures

    But they live in denial because they both that the car was calling just fine when they did it that means nothing. A 8 year old with a single hose with no gauge can get a Prius the blow cold. There’s a lot of individuals boast on how many compressors they have changed that are the whack off shaking can kind of guys with the single hose..

    The reason they had to change so many compressors, because they were the cause of the compressors to go out in the first place, because of the unfortunate customer who use them as their technician.
     
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  20. Mendel Leisk

    Mendel Leisk Senior Member

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    ^Why I leave it to the pros.