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Air Conditioning options *UPDATED*

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by heavy4x4, Jul 7, 2003.

  1. heavy4x4

    heavy4x4 1/2 ton status

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    The AC in my truck hasn't worked well for several years. And, about 3 months ago, the compressor leaked fluid out the back and then stopped leaking so I didn't really care. But, I think that just completely de-pressurized the system because now I virtually have no AC. So here are my questions:

    1) Who has done the R-134A refrigerant re-charge? How much did it cost? Where did you get it? And most importantly, how do you do it? Do I need to replace all the lines, condenser, evaporator, etc? I realize I'll probably need to get a new compressor cuz it doesn't seem like mine will work anymore after it sprang that leak.

    2) Since I'm pretty sure I'll need to get a remanufactured compressor ($170 from LMC), should I just do that and then have a shop charge it with R-12? How much will that run? Do I need to replace all the lines and stuff if I do that too?

    Basically I'm looking to do whatever is cheaper/easier.

    Please give me your input and help. I'm pretty clueless when it comes to AC systems.
    Thanks.


    UPDATE:
    I decided to go with the R134A retro kit. Here's what I needed to do:
    I bought a remanufactured compressor from the local parts store because I knew mine had a leak and was not going to hold vacuum or an A/C charge. In order to have the warranty on the compressor be good, I had to replace the accumulator/dryer assembly as well. I did all of this stuff in my driveway to keep shop labor down. Then I had my next door neighbor who's a mechanic take my truck to the shop he works at where he purged out the old stuff, added the R134A fittings, drew vacuum to make sure the A/C charge would hold, and then filled it with 3 lbs of R134A. Total damage was around $360 with everything I stated above and also a bottle of oil to put 2 ounces in the compressor and 1 in the dryer.
    Just a note for those who live in Wisconsin - it is the only state in the United States where you cannot buy cans of R134A at a parts store unless you are a licensed dealer or mechanic. But, even if I could have purchased the R134A over the counter, I would have had a shop draw vacuum on it anyway to check the system for leaks.
    I'm happy to say I've got A/C again. It blew nice cold air on my trip to northern wisconsin this last weekend 3 1/2 hours each way.
     
  2. Mastiff

    Mastiff 1/2 ton status Premium Member

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    Re: Air Conditioning options

    Man, I'm not in as bad a spot, but almost. When I had my motor replaced, they must have just released all the R-12 or something, because I've had no AC since. Now that it's like 90 degrees and 90%, I'm thinking about it. Turns out, it'll cost me over $300 to get charged up! /forums/images/graemlins/shocked.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/frown.gif /forums/images/graemlins/confused.gif

    Do I have any reasonable options here? Should I drive to Mexico and get it charged there or something? Jeez, this is ridiculous.
     
  3. Living Large

    Living Large Registered Member

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    Re: Air Conditioning options

    Just converted my 91 sub. to 134a. On the west coast, it was cheaper to convert to 134a, than to repair the exsisting R12 system due to the $56.00 per pound of R12 freon. IMO, have a shop do the work. The reason being is the system MUST be evacuated/pumped down to remove all moisture and contamination from the system, or it will not perform as expected. I replaced the compressor with a new GM unit. The rebuilt compressors have a bad reputation of early failure. I also replaced the expansion valve, orfice tube, and dryer. There is a new expansion valve and orfice tube designed for extreme temps.(100+)degrees. After we finished the conversion, a quick road test of 3 miles brought the center vent temp. down to 37 degrees on a 103 degree day. Performance has exceeded my expectations( the shop was also very surprised, and said it must be the new expansion valve, and orfice tube) Yes, it is true, their are R12 substitutes, but be advised that the experts have found accelerated oil break down, o'ring failure, and hose problems. It seems that the chemical make-up is not compatable with some major components. These chemicals are being sold as a great alternative, but without proper install instructions, and even experienced mechanics are getting themselves into trouble. While their is a kit at your local discount auto parts store, buyer beware. Pay once, cry once. FYI here is the new orifice tube "Smart Orifice Valve" NAPA# 707324 said to reduce the vent temps by 5-15 degrees.
     
  4. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    Re: Air Conditioning options

    R-12 is very expensive but works the best in those systems.
    R-134 is an option but I've seen it not work the best for some guys.I charged my system with a freeon called Freeze-12,its an r-12 knockoff but works good in my system. I had to replace my whole system because I had some leakes but it sounds like your system is in good shape if it was just working. Things that you have to replace no matter what is the dryer,(silver can) accumulator and the compressor. /forums/images/graemlins/cool.gif

    85K5 14bolt/10bolt 3/4 ton 35"boggers 16.5x14 welds,big horse 406SBC/700r4, ice cold A/C /forums/images/graemlins/thumb.gif /forums/images/graemlins/k5.gif
     
  5. gravdigr

    gravdigr 1/2 ton status

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    Re: Air Conditioning options

    R-12 is insanely expensive because it contains chlorine. From what my HVAC friend says R-12 is more effecient than R-134a, therefore you can use a smaller evaporater. You can run into trouble with a R-134a conversion if the evaporater is too small since it was designed for R-12. Apparently it works better on some vehicles than others, it seems large fullsize vehicles like lincolns, Impalas, and fullsize SUVs have no trouble. But compacts like civics, chevettes and the like do not work well.
     
  6. heavy4x4

    heavy4x4 1/2 ton status

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    Re: Air Conditioning options

    Thanks for all the help so far. I'm also reading up on it on various sites I found using searches.

    Sounds like everything just needs to be cleaned out well, the dryer replaced, and then you can put in the r134a. It says to use about 85% (r134a) the amount of R12 the system holds. R134A also runs at a higher pressure than R12, so any slight leaks you have with R12 will definitely leak with R134A.

    So, next question I guess:
    Say I go ahead and get a remanufactured compressor from LMC. Will that just bolt on in the sense that I don't need any special tools and is it safe to remove the lines and stuff? Then, after I put the "new" one on, what else NEEDS to be replaced to have the system ready to be charged? After I do that, I'd take it to a shop to have a new charge of R12 put in because at this point it sounds like the easier thing to deal with. So, anyone have an estimate on a price for a shop to recharge a (5lb???) R12 system? I'm assuming they'll need to purge all the old stuff out too. Would that be bad to have that old stuff purged out through a new compressor and ____?

    Thanks again.
     
  7. Dale fan

    Dale fan 1/2 ton status

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    Re: Air Conditioning options

    If your going to replace your compressor you might give some thought to doing the 134 swap. No matter what you do, replace your dryer. If you do the swap you will need to change orfice tubes. The drawbacks to the 134 is the not as cool temp, although it will get cold, and it will leak through your existing rubber lines gradually since the molecules are much smaller than R12. You can get "barrier" hoses to stop that though. Since these are high interior volume vehicles I would probably stay with the R12 since it will blow slightly cooler, and do most of the work myself. I had a 134 swap done by a shop on my ext. cab Sierra and it isn't quite as cold as it was before. 134 is very picky about the pressure levels for maximum cooling in an old R12 system.
    If you tackle it yourself you might have a shop evacute and flush your system. You really need to try and find the leak by running some dye through it if it will still cycle although it sounds like your compressor is leaking. Go ahead and replace your o rings while your at it. Getting R12 is very easy. You can take an online EPA 609 certification test for $15 to $20 and be able to buy it over the counter at parts stores that still carry it for around $35 a can. You could also buy off Ebay for around $20 a can but you will have to have the certification. The test is open book and you can take it here. http://www.macsw.org/store/dept.asp?dept_id=4
    Give it some thought but I also recommend a new compressor like the previous poster said.
     
  8. azblazor

    azblazor 1/2 ton status Premium Member

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    Re: Air Conditioning options

    I have used the $30 dollar conversion kit from Checker. The R12 system was working somewhat (89 G20 Chevy van with dual air). I just evacuated the R12 system with a vacuum pump for 20 minutes, added the R134A fitting and sticker, added the R134A with special oil which is compatible with the R12 oil. Works fine! I live in Phoenix Arizona - today is 113 Deg Far. I will never fix another auto AC and not go to R134A.
     
  9. heavy4x4

    heavy4x4 1/2 ton status

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    Re: Air Conditioning options

    Wow, that's really good news. So, could you maybe go more in depth as to how you hooked everything up and how you drained your old system?

    As for the compressor issue: NEW units are expensive (I want to say like $400). If I don't go that route (which I may, actually) would I be better off buying a remanufactured one or going to a junkyard and finding an OEM one that doesn't leak? Basically what I'm saying is, are these remanufactured ones rebuilt OEM units or are they a foreign look-alike part that doesn't work too well? /forums/images/graemlins/smirk.gif
     
  10. 87sm465np208

    87sm465np208 1/2 ton status

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    Re: Air Conditioning options

    do the autozone kit for 35$, try it, the stuff has leak sealer in it, oil, and R-134a, i bought the QUEST brand, worked for me, and the AC hasnt worked since i owned the truck 1 and a half years ago, and i finally Risked the 35$ to get it going, and im not regreting it, especially last monday night, jump in that truck and crank it on MAX and put the blower on high and thermostat on cold, hell yea! /forums/images/graemlins/thumb.gif.

    /forums/images/graemlins/usaflag.gif /forums/images/graemlins/truck.gif
     
  11. Blue85

    Blue85 Troll Premium Member

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    Re: Air Conditioning options

    [ QUOTE ]
    "Smart Orifice Valve" NAPA# 707324 said to reduce the vent temps by 5-15 degrees

    [/ QUOTE ]

    Isn't this the VOV? Variable Orifice Valve, it has a sliding piston that meters the liquid refrigerant based on pressure. There is no expansion valve in these vehicles. You generally have either an orifice tube OR an expansion valve. The perform the same task. The orifice tube is more reliable, the expansion valve has potential to give a little more performance. The VOV is almost like a compromise between the two.

    Also, as to somebody's comment about the cost of R-12, it has nothing to do with Chlorine. The cost is based on supply and demand. Since it has been illegal to produce R-12 in the U.S. for like a decade, the supply is constantly diminishing. In fact, you can't really buy "new" R-12 anymore. You are paying that high price for used refrigerant that they already charged somebody to remove from their car. The price will only continue to go higher, so I would recommend switching to a new refrigerant as soon as you need a new charge.

    Once the system has been opened, you have to vacuum it down. This removes all of the air. The system can not work right with any air in it. It is important to draw a deep vacuum because this causes any moisture in the system to boil off and get sucked out. If you remember back to Chemistry class, the boiling point of water is only 212F at atmospheric pressure. You want to draw a deep enough vacuum to move the boiling point down below the outside air temp. Moisture is bad.

    You can do all of the work yourself except for the recovery and the vacuum, unless you can get access to equipment that can do this. If your system is already empty, the recovery is not needed anyway.
     
  12. azblazor

    azblazor 1/2 ton status Premium Member

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    Re: Air Conditioning options

    Well, to be completely law abiding you should have a AC shop remove the R12. Or if you were so inclined you could hook up your gages, take the yellow center line to your vacuum pump - remove the cap from the "tee" fitting on the vacuum pump intake - and slowly open your valves on the gages to release the R12 into the atmosphere there by becoming a ozone depleting enviromental criminal.

    I added the R134A fitting adapters to the R12 fitting first thing.

    After the R12 pressure is to zero, put the cap back on the "tee" and start your vacuum pump and let it pull a vacuum, you should get 28-29 inches showing after a few minutes. Let it run for 15-20 minutes - shut your valves for a while and see if the vacuum leaks (air leaks into system). If it stays up there for 15 minutes or so (or in my opinion only leaks a couple of inches) you have a pretty tight system. Then remove the yellow line from the vacuum pump and connect it to the cans of R134A/leak sealer that came in the kit. (BTW the kit also comes with a hose and low pressure gage) You can borrow the vacuum pump and real gages from the parts store. (For a charge against your Credit Card which is refunded if you return the equipment)

    I have used the remanufacted Air Compressors from the Checkers and Auto zones before. Yeah they are not as reliable as a brand new compressor but for 120 vice 300+ thats is a big difference. And if they last the warranty period they will probably go for a few years at least.

    Phoenix temp today 116-118
     
  13. Blue85

    Blue85 Troll Premium Member

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    Re: Air Conditioning options

    [ QUOTE ]
    You can borrow the vacuum pump and real gages from the parts store

    [/ QUOTE ] Holy Cow! What parts store has a loaner vacuum pump? That would be great! I have been paying $15 at a local service shop for hookup to their pump.
     
  14. daimok

    daimok Registered Member

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  15. azblazor

    azblazor 1/2 ton status Premium Member

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    Re: Air Conditioning options

    I have a brand new Mastercool 4CFM vacuum pump in my Garage that I picked up at AutoZone. I may just keep it.
     
  16. heavy4x4

    heavy4x4 1/2 ton status

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    Re: Air Conditioning options

    Hey, thanks for all the help everyone.

    I think I'm gonna try it. Here's my plan, see if you can find any problems:

    1) first check for the availability of the R134A retrofit kits and refrigerant cans (this stuff was not-for-sale in Wisconsin a couple of years ago, but I've seen it in the Checker ads recently)
    2) Get a remanufactured compressor from LMC (or from _________ - any suggestions?)
    3) Add the little R134A adapter fitting thingy
    4) Have a shop evacuate my old R12 system
    5) Take it home (or I suppose have the shop do it if they're going to make me) and put the reman compressor on
    6) Take it back to the shop and have them vacuum the new setup
    7) Add the R134A using cans I bought at an auto parts store (how do I know when to stop filling - I've read just put 85% the R12 capacity in, or add until the temperature coming out of the vent starts to rise a little, or via a pressure gauge - which do I do/ how do I do it?)
    8) Enjoy an air-conditioned truck on Wisconsin's 85 degree days with humidity that makes you sweat drinking a glass of ice water.

    Thanks again, I'd be lost without this help.


    EDIT: I went to Autozone and they said that the refrigerant is still illegal to sell in Wisconsin. So, I was thinking I would have to go out of state to get it, but the Checker auto parts store website says that the Advance Auto Parts store near me has the refrigerant in stock. I'll have to check on it tomorrow. Anyway, out of this list of things, what do I need to do the swap? Also, do I need a new accumulator/dryer? I thought I read that somewhere. /forums/images/graemlins/1zhelp.gif /forums/images/graemlins/ears.gif
     
  17. bigtruck87

    bigtruck87 Registered Member

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    Re: Air Conditioning options

    i'm not trying to steal the post or anything but while everyone's minds are on a\c. my air works good and blows cold but the truck starts to run hot when it is on. i usually run at anywhere from 210 to 190 but the temp gauge just keep climbing when the air is on. any ideas? i was thinking maybe the radiator is partialy cogged and it is good enough to handle normal operation but not the added stress of a\c.

    i kinda learned things backwards. i'm 19 and fix cars at a lincoln dealer so i learned on all new product (fuel injection, electric fans, etc.) so older stuff sometimes confuses me. thanx for any help
     
  18. Dale fan

    Dale fan 1/2 ton status

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    Re: Air Conditioning options

    yeah, definitely put a new dryer on. Any AC shop will demand it for warranty as any trash likes to stay in there and could clog the system again. You could check out compressor prices at Advance since any warranty claims would be much easier instead of shipping it back to LMC. See how much a new orfice is since I don't think you will be pleased with the cooling unless you change it to one that is designed for the higher pressures needed for 134.
     
  19. DOCKAWI650

    DOCKAWI650 Registered Member

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    Re: Air Conditioning options

    the prices on air conditioning charging is ridiculous....my dad owns a car lot and he showed me how to do it....it takes about 4 or 5 minutes and 2-3 cans of freon which arent much at all.
     
  20. Blue85

    Blue85 Troll Premium Member

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    Re: Air Conditioning options

    Venturi pumps are cheap, but it is hard to draw a deep vacuum like a real vacuum pump does. Even the worst pump can draw deep, it just takes it longer. With the venturi pump, you need a lot of CFM from your air compressor. If you can't get the vacuum low enough, you may want to rent or borrow a big compressor. Crank up the pressure, find yourself some ear protection and let it rip. /forums/images/graemlins/grin.gif
     

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