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Tuesday, May 12, 2015

Air Conditioning compressor recharged and now again

My 1998 S10 had the compressor replaced about 6 years ago and I had it evacuated and charged by a licensed professional. This year, now that the heat has arrived, it seems to have much less cooling capacity than it did last year. Rather than completely evacuate the system and add the correct total amount of refrigerant, is there a way to just "top it up" instead of removing all of it and starting over? I have a R-134 gauge set and a vacuum compressor for evacuating the system if I need to do that. But can I add, say 1 or 2 oz. of refrigerant at a time and see if the A/C seems to be cold enough, or can I go by high side pressure and add a bit at a time, waiting for the pressure to stabilize, until I reach a certain pressure? I would guess that the ambient temperature affects the pressures I would be reading with the gauge set since the aftermarket kits have an adjustment for that on the simple gauge they use on the low side. If the aftermarket kit is the best approach, I have the hose from one of those that I used to use before I bought the gauge set and vacuum compressor to do a complete job on another vehicle of mine a year ago.



  2. I am surprised that temperature has quite the effect that it does on
    the system pressures, but I did expect some differences.

    Thanks so much for the idea to web search. I thought this would be
    some kind of tribal knowledge that I wouldn't find so easily. What I
    didn't want to do is do a web search and just assume that what I would
    find would be safe to apply in my case, but this seems to be the
    normal pressures seen in typical R134 systems. I will be able to do
    this probably tomorrow. I'll get the dye tomorrow also since I don't
    know if the professional added dye or not. I did add it to the car I
    did the complete job on in case I ever needed to find a leak.

    Somewhere I have a UV penlight for finding leaks.

  3. I do have the whole kit actually. I only mentioned the one part of the
    kit. I just am not sure where the light is, but will look for it
    later today when I find out if I have a can of R134 in the garage or

  4. I used to use that method but many vehicles now no longer have a sight
    glass. Neither of my Mazdas do and my S10 doesn't have one as far as
    I've seen.

  5. It might be cheaper to replace the compressor with the clutch, unless
    the clutch can be changed out while the compressor is still on the

    If the compressor needs to be removed anyway, you'll have the
    additional cost of evacuation, reinstallation, and recharging the
    system. I bought my replacement compressor new on ebay for over $100
    less than the person who was doing my replacement could get one. (It
    came with the clutch.)

    If the clutch can be changed out without removing the compressor, I
    would think that would be the best approach money-wise. But if your
    mechanic works cheap, and doesn't charge a lot for changing out the
    compressor (and the other things that have to happen also), then you
    might be better off to get the new compressor. If you plan on keeping
    your vehicle a long time, knowing you have a good compressor/clutch
    might give you some peace of mind, too.

    If you replace the compressor, you'll probably want to replace the
    receiver/drier also. It's not very expensive compared to the clutch.

  6. Thanks, Sounds exactly like what happened to my air conditioning

  7. Temperature has quite the effect that it does on
    the system pressures, I really unknown about this.