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AC compressor DIY

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by extricate, Sep 7, 2016.

  1. extricate

    extricate New Member

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    Hey Prius forums,

    So I recently had my car diagnosed and sure enough I need to replace the AC compressor. I'm gonna make this a DIY job, and just had a couple questions before I get started. Right now I'm planning to buy a used compressor with low miles, and am just gonna put it on there.

    Do I need to replace the receiver drier in the condenser? It's a cheap part. Sometimes I go to yourmechanic to see what they would replace and figure out if I should follow the same logic.

    Should I add new ND-11 oil to the compressor even if it comes with oil? Could I also use the generic stuff from carquest and get the same results? Should I recycle the oil from my compressor? I'm just curious what my options are here.

    Also I think I read somewhere on these forums or possibly somewhere else that there was a guy who built a housing for his AC compressor, so that it wasn't sitting right on the ground. I've read the placement of the compressor makes it prone to damage, so if I can build and install a cheap cover there I might want to go ahead and do so.

    Outside of the techinfo toyota manual, which I believe you have to pay for, do you guys know of anywhere offhand that would provide detailed DIY instructions?

    Last question, the dealer recently checked for leaks and found none in my system, they also pulled a vaccum on it. Would I have to pull a vaccum on it again to properly charge the system? I also need to find instructions on charging the system in a Prius to make sure I'm doing that right.

    Thanks a lot in advance for taking the time to read my post. I'm still a bit of a newbie when it comes to working on cars, but between lurking these forums and you guys getting back to me on my posts, I'm really learning a lot. It's greatly appreciated!
     
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  2. exstudent

    exstudent Senior Member

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    You seem to be getting in over your head.
    Your local library may have Chilton/Haynes manuals for Toyotas and even auto AC systems, which would give you a good primer. Ask your library if you can get online access to Chilton/Haynes! You can fine tune your knowledge and understanding with the factory manual.

    Sound reasoning and pragmatic to do.

    1) The used donor compressor may have some residual ND-11 oil in it, definitely not enough, and possibly other contaminants. Once all components are installed, spend the money to have the entire system flushed by a competent shop (ideally a Toyota dealer), so you can start from scratch (a clean slate).
    2) Carquest's ND-11 vs GENUINE Toyota ND-11. Does Carquest guarantee it is absolutely compatible w/ Toyota's electric compressor?
    3) Do you have an AC Manifold gauge set that has only been used on a Toyota/Lexus hybrid? Why? You don't want to contaminate the hybrid AC system w/ conventional PAG refrigerant oil, due to the gauge set in question having been used on a conventional vehicle AC system.

    Are you driving unpaved, dirt/gravel roads? Do you foresee yourself driving such roads? Are there many potholes on the roads you drive? Is there a lot of road debris on the roads you drive?

    The $15, two business day subscription, will be one of the BEST investments, you will have made. Toyota - New Subscription The DIY instructions don't get better than this. Some users have reported of getting four calendar day access by starting on a Friday (say 5PM; business day one), with access ending sometime on Monday (4:59PM; business day two).

    This person found a way to covert CHM files to PDF. If you know of a way to preserve CHM, then do so. He also downloaded the factory manual for the two Toyotas he owned!
    Toyota TIS download tips | PriusChat

    Correction: Last two questions.
    1) Yes, vacuum is required to recharge the system.
    2) All questions about charging the AC system and specifications (quantity of ND-11 oil and R134a gas), and a wealth of other info, are in the Toyota factory manual. It behooves you to make the $15 investment, to get the Toyota factory manual for your Prius.
     
    #2 exstudent, Sep 8, 2016
    Last edited: Sep 8, 2016
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  3. extricate

    extricate New Member

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    Update:

    Thanks for the reply exstudent. I used a lot of your recommendations during my repair.

    So I ended up purchasing a salvage/recycled part from a supplier in Kentucky for about $82 total including shipping. My other supplies included 2 cans of Freon ($5 each), ac receiver drier (15ish dollars), and a can of generic hybrid compressor oil for about 33-40 dollars including shipping from advance auto parts. I tried to look for nd-11 but was having a hard time finding it on the Toyota parts website and I honestly didn't wanna be bothered driving to the dealer... plus this stuff was cheaper.

    I bought the subscription access from the Toyota TIS for 2 days for $15. I basically used the snipping tool in windows and cut out multiple parts of the repair and made pictures out of the instructions. After that I uploaded these files online to a free PDF converter to make it into one convenient PDF for me.

    So in the instructions it tells you to remove all the covering/floor boards. You don't actually need to do this to complete the repair and taking mine off seemed to be a pain. I removed a couple bolts and just pressed on.

    Now there was NO actual Freon in my system so I don't recommend anyone remove the compressor without a proper evacuation of the AC system. The system is pressurized and when you remove the discharge hose it'll blast the pressure out, which I imagine could contain Freon in it if your system was not evacuated.

    Pulling the compressor out from here was rather easy, just a couple bolts, and the hose connectors and you're good to go. My new compressor did not come with any oil inside of it. Unfortunately I was not able to adequately measure the amount of oil in my old compressor, so I kinda had to guess a little bit when putting new oil into it. The manual says "Oil capacity inside new electric inverter compressor 100 +15 cc (3.52 + 0.53 fl.oz)) (Remaining oil amount in the removed compressor assembly with the motor (with motor compressor assembly)) = (Oil amount to the removed before installation). I think that means 4 oz total, 0.53 for the smaller part of the compressor, and 3.52 for the larger part.

    I added maybe 2 oz total to my compressor. It seemed like barely any drained from it originally and I'm a little concerned that I may not have put enough in. Is there any way to accurately tell if I have enough oil in it or not? Just for grins I recorded my compressor on max AC and max blower.

    Edit: Here is a link to the AC compressor sound

    So for recharging my system I used pure 134a and used a recharging tool I had bought a while ago at Autozone and meant to take bake. Now this is not the best way to do it and I only added 12oz of Freon to the car in spite of the capacity being about 16. I didn't want to have an open can of Freon attached to my tool for who knows how long (as we are coming up on winter in my locality).

    In any event my AC works, so that's a good thing. I've attached the files needed to perform the compressor removal, install, and refrigerant recharge in case anybody needs them.

    Thanks again community, and hopefully I can figure out if I have the right amount of oil in the system.
     

    Attached Files:

    #3 extricate, Sep 18, 2016
    Last edited: Sep 18, 2016
  4. ChapmanF

    ChapmanF Senior Member

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    After a while you recognize those steps at the top of all the procedures where either the 12 volt battery ground cable, or the HV battery service plug (or, as in this case, both) will be removed for safety. It's like the number of recipes in your cookbook that all start with "chop 1/2 medium onion."

    The rear no. 3 floorboard is what has to come out to reach the battery ground cable, but it's held in place by the deck floor box (which is also in the way of the HV service plug), which itself is under the rear no. 2 floorboard. Right? So basically whenever you see a procedure that starts with removing those items, your brain goes straight to "ok, next they're going to tell me to safe off the power, which is the real point here."

    -Chap
     
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  5. extricate

    extricate New Member

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    Yea that makes sense Chap! Silly me I thought all the floorboard stuff was underneath the car, but yea I did remove the battery cable and the service plug for sure. I wasn't trying to get electrocuted.
     
  6. Mina kamal mina

    Mina kamal mina New Member

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    Thanks a lot for your advice.
    I am thinking to diy it but I want to know Is it worth to change ac compressor?
    Toyota dealer mentioned that the new compressor might broke down again because there might be metal shavings in the ac system.
     
  7. Jetta95

    Jetta95 Junior Member

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    So did you end up running vacuum before the recharge?
     
  8. mr_guy_mann

    mr_guy_mann Senior Member

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    Well, if you don't evacuate the system before recharging it, then it won't work very well at all- system pressures will be very high (air doesn't condense). Also it likely won't work for very long, as air and moisture will react and form corrosive acidic compounds.

    Posted via the PriusChat mobile app.
     
  9. Jetta95

    Jetta95 Junior Member

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    If I am going to replace the receiver drier won't that help with the moisture? When I did our van AC I did not vac the system and it is still working into the second season. I didn't know if the Prius would be the same? The OP did not state that he ended up doing a vac and sounds like it turned out ok. I know there is some debate on this (some think it's overrated) so I was wondering how it works on a Prius.
    My 2005 now has 270k miles so I am doing it on the cheap, $70 used compressor, RockAuto hybrid oil.

    Also is it recommended to change the water pump belt while working in there, mine is cracking.
     
  10. ChapmanF

    ChapmanF Senior Member

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    It's common knowledge that evacuation is needed before charging an A/C that's been opened, for all the reasons mr_guy_mann explained. But something being common knowledge doesn't mean everyone knows it. You can imitate somebody who didn't know it, but I wouldn't want to take that chance. There are even more ways for moisture and acids to degrade a Prius electric compressor than there are in a conventional mechanical one.
     
  11. Jetta95

    Jetta95 Junior Member

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    If "moisture and acids" from ambient air degrade a Prius compressor then it must already be degraded since the salvage yard left the ports open?
     
  12. mr_guy_mann

    mr_guy_mann Senior Member

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    It mostly has to do with the oil used in most 134a refrigerant A/C systems. That oil will absorb moisture (which can cause corrosion by itself), and when that moisture and oil are compressed (& heated) to hundreds of psi, that's when acids form. So yes, a used compressor that's been left open isn't a great option, depending on how long it's been exposed, and what the local conditions are. High humidity is the killer. That can be offset some by completely draining the old oil from the compressor before installing. Read the service manual as to how to add new oil so you don't damage the compressor.

    Using a strong vacuum pump to empty the system removes the air and boils off any moisture (as long as the ambient temperature is high enough). The dessicate in the receiver drier is designed to remove small amounts of moisture over a long time, basically maintaining the system over years. It would likely get saturated if the system was not evacuated.

    Posted via the PriusChat mobile app.
     
  13. ChapmanF

    ChapmanF Senior Member

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    I would probably not accept an A/C compressor from a salvage yard that had not plugged the ports.