Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

suburban air conditioning... r-12...r-134??

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by muddysub, Apr 29, 2002.

  1. muddysub

    muddysub 1 ton suburban status Staff Member Moderator GMOTM Winner

    Joined:
    Jun 23, 2001
    Posts:
    10,451
    Likes Received:
    489
    Location:
    my garage, Henderson, NV
    i know i have r-12 now, would it be worth it to switch to r-134a? that and how much r-134a would my suburban need? i have front and rear air.

    ps: living in 'vegas, I NEED AIR CONDITIONING SOON!!!!!
     
  2. Esteban86K5

    Esteban86K5 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    3,712
    Likes Received:
    0
    Location:
    Bakersfield, CA
    Keep your r-12. I have the r-134 and it is no where as cold as the r-12.
     
  3. René

    René 1/2 ton status

    Joined:
    Mar 14, 2002
    Posts:
    208
    Likes Received:
    0
    Location:
    Michelbach, Germany
    In your place, I would also take R12. With R134a the achievement of the plant doesn’t only sink. You need new seals, a new dryer and connecting piece for the change. The R134a must be renewed every three years, because it evaporates by all lines (diffusion). And the compressor is more badly lubricated. But unfortunately R12 is forbidden in Germany.

    You need little more than 6 lbs.
     
  4. DesertDueler

    DesertDueler 1/2 ton status

    Joined:
    May 23, 2001
    Posts:
    3,106
    Likes Received:
    0
    Location:
    Phoenix, AZ
    My 87 Suburban with front and rear air take 5.25 lbs of r-12. Stick with r12. Pay the extra money for it and you will be happy. r134 just doesnt cool near as well. r134 also runs at higher pressures than r12, so parts wear out quicker ie compressor.

    Dan
     
  5. mike reeh

    mike reeh 1/2 ton status

    Joined:
    Jul 23, 2001
    Posts:
    752
    Likes Received:
    0
    Location:
    San Diego, CA
    make sure your system is up to par and go with R12.. 134a does a good job in a system designed for it, but even then I prefer R12. Except the stuff is expensive. I have 3 12oz cans of R12 staring me in the eyes right now, I cant wait to put it in my truck..

    mike
     
  6. Blue85

    Blue85 Troll Premium Member

    Joined:
    Jul 26, 2000
    Posts:
    9,072
    Likes Received:
    483
    Location:
    Grand Rapids area
    Well I'm taking the other side here. I forked out almost $200 for a charge about 3 years ago. That didn't even last me 2 summers. That is unacceptable in my book. Even after the system no longer worked, the shop was unable to find any significant leak. I want to do the service and maintainance myself and I don't want to get certified just to buy a huge tank that costs $500.

    So last spring I converted to R-134. Every new drier is compatible and they are relatively cheap. You just need to flush the lines and replace the O-rings. Then you need a vacuum source to remove all air and moisture (the low pressure of the vacuum makes water boil at room temperature).

    Does it cool as well as R-12? no. Does it cool better than the system that is low on R-12 and has to be professionally serviced? Of course.

    But there are some things you can do to make up for the loss in efficiency:
    -Use a VOV. These valves give you a little better cooling at idle compared to a stock orifice tube and extend compressor life.
    -Switch to electric fans. You notice the loss of cooling the most at idle because the stock fan is not moving enough air. Electrics can provide full flow regardless of engine speed. Adding a booster "pusher" fan or two on the front of the condensor also helps. You can cycle them with a relay along with the compressor clutch. They need to be high flow, though.
    -Use an adjustable clutch cycling switch. This adjusts the cutoff pressure on the low side. You're in luck. Your system probably already has one.

    All of the money I spent on the conversion and upgrades was less than the cost of one charge of R-12, which I would lose before too many years anyway. The performance is now rougly equivalent to a stock R-12 system

    I don't know anything about the rear A/C units, but having both front and rear will let you tolerate the loss of cooling capacity much easier.
     
  7. arveetek

    arveetek 1/2 ton status

    Joined:
    Mar 1, 2002
    Posts:
    722
    Likes Received:
    0
    Location:
    Granby, MIssouri, USA
    I used propane.

    That's right, I said propane.

    Ever hear of R-12a? It was an R-12 substitute that came out a couple of years ago. It was just propane in a 12 oz. can.

    I also agree that R-12 is better than 134a, but you just can't get it anymore, and if you do find some, it's probably mixed.

    After talking with several mechanics and tractor places, I decided to try propane in my '81. It was getting low, but it still had some R-12 in it.

    I know of several guys who have nothing but propane in their truck's A/C system.

    I do RV A/C work which uses R-22, so I had all the equipment necessary. I rigged up a way to get propane out of my 20 lb. bottle and into my truck's A/C system. I tell you what, this thing is blowing colder than it ever has!

    WARNING: attempt at your own risk. Obviously LP is much more flammable than R-12, but it does work very, very well as a refrigerant. If it leaks, you might have a fire hazard, especially if it blows all at once.

    In my mind, it's not anyworse than having gasoline and electricity flowing together underneath the hood (or diesel, in my case).

    Good luck.

    Casey
     
  8. mike reeh

    mike reeh 1/2 ton status

    Joined:
    Jul 23, 2001
    Posts:
    752
    Likes Received:
    0
    Location:
    San Diego, CA
    I have heard of this. Never talked to anyone that uses it though.. I heard its GREAT as a refrigerant, it was just dropped due to its safety hazard. I really like this idea, did you use the recommended amount & type of oil for R12?

    as for R12, it cost me $20 to get certified and I can buy it at pep boys, kragen, etc when I need it. (or I can buy it in large quantities)

    What I really want is the manifold & guages to do R12 work. something that I can connect a vacuum pump too also. Ive looked around but to no avail.

    mike
     
  9. arveetek

    arveetek 1/2 ton status

    Joined:
    Mar 1, 2002
    Posts:
    722
    Likes Received:
    0
    Location:
    Granby, MIssouri, USA
    Since I added the LP to just a low-charge system and not an empty system, I didn't add any oil.

    My K-10 is next on the list. It's completely empty, and I don't know if there's anything majorly wrong with the system or not. It's all there, but it wasn't working when I bought it. I plan to vacuum it down, and add some oil to it, and charge it back up with propane.

    Casey
     
  10. GMMANIAC

    GMMANIAC Registered Member

    Joined:
    May 1, 2002
    Posts:
    53
    Likes Received:
    0
    Location:
    San Antonio, Tx.
    Switch to R134. With a few minor mods you can make the system cool better than the R12. I converted a friends Sub and I also did my Blazer. One thing that works real well is a self adjusting orfice tube filter. You should also install an electric cooling fan. I install the fans with a relay that runs off a Mercedes high pressure switch installed in a fitting that you attatch to the condensor.
     
  11. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    I worked with a guy about 15 years ago that had done the conversion to propane. But he had done some research and found that a certain mixture of propane and butane actually produced the coldest output. He called it his "propain" conversion. /forums/images/icons/wink.gif
     
  12. White Knight

    White Knight 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    889
    Likes Received:
    0
    Location:
    Ft Worth,Texas
    Did the switch on my Sub, it has front/rear A/C and I haven't noticed any difference in cooling, when one considers that you're trying to cool a football stadium in volume....its doing just fine.

    White Knight
    Christian/republican/redneck three of the best things in life
     
  13. arveetek

    arveetek 1/2 ton status

    Joined:
    Mar 1, 2002
    Posts:
    722
    Likes Received:
    0
    Location:
    Granby, MIssouri, USA
    I've been driving around for about a week now with my K-10 fully charged with 100% propane. It's working great and blowing cold! I vacuumed the system down, added some R-12 oil, and then charged it up with LP. So far so good!

    My compressor is making some odd noises, it almost sounds like a turbo, with a whine that corresponds to engine rpm. Hope it's not about to go out.

    Casey
     

Share This Page