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AC not cold but overpressurized?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Nathaniel_Thorne, Jul 11, 2024 at 11:23 PM.

  1. Nathaniel_Thorne

    Nathaniel_Thorne New Member

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    I have a 2013 Prius Three with around 90k miles. A few weeks ago I started noticing the ac didn't feel as cold and then eventually it started blowing nothing but hot air. First thought was to check/add freon so I bought a can and gauge Problem is when I plugged up the gauge with the freon, it immediately went into the red. I didn't add any freon or squeeze the trigger because it went halfway to the red. I checked it again it different conditions, such as running vs not and at night when Temps come down. Everytime the same thing. I then thought maybe the serpentine belt and discovered this car doesn't have one or at least the compressor is electric and doesn't use it. I'm trying to figure out if there are other steps I can take or if there's anything I should know before going to a mechanic.
     
  2. Tombukt2

    Tombukt2 Senior Member

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    Okay you connect the can to the low pressure side The only port it will connect to when the car is not running and the air conditioning is not on and the remotes in your pocket nothing is happening The gauge should be buried on a pretty full system that's past 80 well into the red if it has a red The minute your other half starts the car puts the air conditioner on low temperature high fan non-recirculate mode You should see that gauge pull down below the green like to 10 PSI and slowly rise up to about 35 37 at that time you'll feel the hose that this gauge is plugged into is getting cold this indicates that the refrigeration cycle is in fact working and you are making cold because you don't feel it in the car is not the refrigeration systems problem usually it's an air damper door not moving so on and what have you there are people that will come along for the Gen 3 that will tell you what you need to unplug and what you need to look at to get your cold air actually blowing back inside your cabin.
     
  3. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    These cars are dependent on a very precise refrigerant fill. As in measured in grams on a calibrated scale. Now that yours is wrong, it is probably best to get it vacuumed out and filled from scratch.
     
  4. Tombukt2

    Tombukt2 Senior Member

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    I only think it was wrong because the car wasn't running in the air conditioning wasn't turned on yet when the air conditioning is turned off and nothing is running there's no such thing as a low and high side that is created when the compressor pumps up pressure and creates a high and a low side or a suction and a discharge side is the reaction of what happens when you operate a pump water gas it doesn't matter so until something is sucking on the suction side is something is pressurizing on the discharge side there's no sides.
     
  5. PriusCamper

    PriusCamper Senior Member

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    Your AC is a variable pressure system... Correct amount of refrigerant is done by weight, not pressure. You have to evcauate the system and measure the weight of the refrigerant and oil. A Shop has an expensive machine to do this. It's not DIY...
     
  6. Tombukt2

    Tombukt2 Senior Member

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    Try what I said above and see what happens You're worried about explosions That's not going to happen Not with the AC system If you get buried in the red the low gauge on top of the can with the car sitting there off perfectly normal if when you start the car and turn on the air conditioning and you hear the compressor run it stays in the red then you need to find the blockage or whatever is going on and that's probably going to be left to air conditioning people but I don't think that's what you have going on until you check and try it you won't know.
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    Maybe they should stop selling these recharge cans.
     
  8. Tombukt2

    Tombukt2 Senior Member

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    They should most definitely stop doing that they should go back to the can tap and cans of whatever gas you're going to use so that people have to buy tools to do it I do agree with that whether any dummy can buy the tools and still perform the operation that's another whole story but to just be able to walk into Walmart and get a can with the gauge and start having at it it's really kind of silly I'm just trying to figure out if he's got pressure going down when the air conditioner finally comes on because with everything off the gauge on the can is doing just what it's supposed to do not blowing off the gauge but bouncing all the way to the end of the gauge this is correct with the car off the minute the car turns on and the air conditioner clicks in it should suck down to almost 14 lb and slowly rise to about 36 close to 40 and then the tube it's connected to should be getting cold and if this is happening his refrigeration system is working reasonable why there's nothing coming out of the vents there's a car electrical problem The damper door is stuck and any position but AC I guess.
     
  9. bbrages

    bbrages Junior Member

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    Did you hear the compressor running? It's probably not turning on.

    There could be any number of different problems with your ac. It's going to require troubleshooting. A set of manifold gauges is a start.