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Converting AC to R-134a

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by surg82k5, Sep 2, 2002.

  1. surg82k5

    surg82k5 1/2 ton status

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    I am cnsidering converting my system to 134a. Right now I am pretty sure there is a leak somewhere in the system. I know I will have to find that, but after that I am not sure of what all I will have to do. How difficulty is it to convert an 82 blazer. Will I actually have to change hoses and other stuff like that. Where is a good place to buy all the seals and other misc stuff I might need. Thanks for the help and any other advice is appreciated.. What price should I expect to pay.
    Sergio
     
  2. Sandman

    Sandman 3/4 ton status Author

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    OK, I just did this on my '92 but the procedure should be the same. You will have to change out the accumulator, $65. I elected to change out the pump as mine was bad, $160. Change out the orifice tube, $12. Get a conversion kit, $35. The goal is to get all of the old lubrication out of the system. You change all of the parts and drain what you dont change and you have to change all of the seals and the fittings. They all come in the kit. The new R-134a is way cheap to buy when you are done. After you change all the seals you will most likely have fixed the leak. You dont have to change the pump but you have to make sure that all of the lube has been drained out of it. It took some hours to do but it was not too bad off. Hope this helps.
     
  3. PGL4VT

    PGL4VT Registered Member

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    I didn't change anything. I simply bought the conversion kit at Advance Auto for $34.99 and did the job in under 30 minutes. No problems. Cools fine.
     
  4. surg82k5

    surg82k5 1/2 ton status

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    Just curious why it is you would have to change the accumulator... thanks for the reply... very helpful so far... havn't done anything yet just gathering information..
    Sergio
     
  5. Sandman

    Sandman 3/4 ton status Author

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    I was told that you had to get all of the old fluid out and that you had to change the accumulator becouse it was not easy to do this. I may have been misinformed but it wasnt too bad.
     
  6. Blue85

    Blue85 Troll Premium Member

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    There are two concerns:
    1st: The old lube (mineral oil) is not supposed to be compatible with the new lube (Ester or PAG), but supposedly the "conversion kits" have somethign to stabilize from bad interactions. So it's best to flush everything, but many have good results without.

    2nd: The accumulator has a descicant (sp?) that absorbs moisture to keep it from doing damage inside the A/C system. Supposedly, this stuff will be broken up by the new lube/refrigerant over time and will get in the compressor, orifice tube, etc. Some have good results without changing it, some have bad.

    What I did is to take the system apart, flush everything out with brake cleaner, blow it dry with compressed air, replace the accumulator, replace the O-rings and then fill it up with synthetic oil (from Australia, compatible with everything). After that, It has to be vacuumed down for an hour or two and charged up.

    If you have some leaks, you'll have to open the system to fix them anyway, so you might as well change the O-rings to the new kind: they probably need it anyway. Accumulators are cheap, too and yours is pretty old even if you weren't changing refrigerants. You can't hardly buy an accumulator or O-ring anymore that is not R-134a compatible.

    As far as I know, the hoses from '82 will be OK. I think they are the same as my '85 hoses, which work great. You should change the orifice tube to one size smaller (couple $$ at an A/C shop) or get a VOV from AC Source or somebody like that.

    I also added a condensor fan when I did mine, which helped a little at idle. I think the VOV is a really good idea. I tried one and apparently got a dud, which is why I run a stock GM white orifice tube. My pressures show clearly that it is a little too big (R-134 has smaller molecules than R-12). Next time I have to open the sytem again, the VOV will go in.
     
  7. surg82k5

    surg82k5 1/2 ton status

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    First of all thanks to everyone for some really great help so far. I actually had another question to ask of you all. Do any of you guys have a link or a pic you can send me of a diagram of the AC system on GM's. I have never worked on any AC systems so i don't even know exactly what these parts are, or where they would be in relation to everything else... would they bein the dash or in the engine compartment. I do know things like the compressor evaporator and accumulator, but that is about it. Things that i have had to take off or move getting to other stuff I have had to fix. Thanks for the help.
    Sergio
     
  8. Thunder

    Thunder 3/4 ton status

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    You might want to check out the message boards over here:aircondition.com BBs
    Try Doing a search first. Your questions on 134a retrofit has been asked there just about as often as people around here ask" How big of tires can I fit under a 4" lift? /forums/images/icons/laugh.gif
    Lots of good info on automobile airconditioning over there.
     
  9. 76k5Blazer

    76k5Blazer 1/2 ton status

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    If you dont get all of the mineral oil out it will form an acid with the new oil and refrigerant eating the seals and reeds in the compressor.The slap on conversion kits are on a list to be banned cause of this.The accumilator / reciever drier has to be changed anytime you convert over. then have it vacuumed down to see if you have any leaks if so find em and repair em. re vac it down then add oil and refrigerant to the specs a manifold gauge works well for this. To do it rite
     

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