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How Do I Recharge My Ac

Discussion in 'Minivans · Pacifica' started by greg.owen, Jul 27, 2003.

  1. fud2468

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    What does it take to convert an earlier Gen 2 to R134, and is it worthwhile to do it?
    Or would it make more sense to trade for a newer one that already has R134?
    Ray Mac.
     
  2. For my 1999 Town & Country, I got one of the cheap recharge kits as my air got warm on me. When I would connect it, however, it read around 55-60 lbs, leading me to believe that it had enough. Idling wasn't sufficient. I had to rev up the engine and once I did, it worked and is now blowing cold.

    Thanks for the help, guys.
     
  3. Dave Z

    Dave Z It's me, Dave
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    Keeping the can warm is essentially advice. Blowing a little out the hose is something I'd never thought of but it makes sense, and I gotta balance the slight leak against preserving the refrigerant already in the system! (Wish they made the a/c systems less leaky in the first place, like they used to in the R-12 days. I know why they leak more now but can't help but think if they really, really wanted to, they could make 'em better. In fact, they do seem to be making progress...)
     
  4. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
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    Some never leak. My wife's Camry had the original charge from 1997-2005, til someone hit the nose of her car. Even then, it didn't leak at all, but the body shop wanted to be sure it wouldn't later, and got approval for a new condenser. No leaks in the last 5 years, either, and I can cool beer in that car.

    My 1992 Dakota has its original R12, according to my brother, the original owner.
     
  5. valiant67

    valiant67 Rich Corinthian Leather
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    Chrysler made changes to the vans for R134. The earlier vans like the 1991 I had used a smaller radiator with a condenser side by side. The factory R134 vans used a full width radiator and condenser.
    You could probably get decent service just by properly evacuating and charging an earlier van with R134, though it may not be quite as cold as the factory R134 system.
     
  6. Dave Z

    Dave Z It's me, Dave
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    Bob, you're lucky. My family's 1999 Corolla (no longer owned) had to have hoses replaced after just four years. Was the Camry R12? (my guess is that it was not since I recall R134a coming in around 1996 but maybe not.)

    My impression was that the change from "reliable" to "leaky" came with R134a.
     
  7. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
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    1994 was the changeover, the Camry is R134a.

    What has caused many recent leaks is that some evaporators and condensers are thinner-walled than ever before, to improve heat exchange and to lower cost. And then they develop cracks and pinholes (such as Chrysler had in the mid-90s).

    R12 hoses used in R134a conversions tend to leak more, since the R134a molecule is smaller, and therefore the hose more permeable to it. When doing a conversion, I recommend NOT flushing the mineral oil out of the hoses, as it can help seal them better. New hose sets should all have barrier linings that are good for both.

    My truck hasn't apparently leaked much in 18 years, as it's still cold. But my 92 Daytona with R12 developed a cracked condenser in 1996 and had to be replaced. And after about 10 more years it had slowly leaked out, so I converted it. The 84 Daytona with R12 finally leaked out enough that the compressor would not engage, so I converted it this year.

    The key is to lubricate the metal gaskets fully with the oil, and to torque all connections to factory spec. It feels too tight when you do it, but my experience is that it then will not leak prematurely.
     
  8. Dave Z

    Dave Z It's me, Dave
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    One issue is that you can't even get a new hose set, at least not a custom fit one, for older cars.
     
  9. ajkbuz

    ajkbuz New Member

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    You definitely have to have the a/c running and the compressor engaged for it to empty the can. And, the pressure in the can has to be higher than the pressure in the system (on the low pressure side).
    After its taken part of the can, the pressure drops in the can and you have to "suck" the rest of the freon into the system by reducing the low-side pressure. It helps a lot to speed up the engine to 1800-2000 rpm, either with a helper in the driver's seat watching the tach, (or I use an adjustable handle ice scraper wedged from the steering wheel to the accelerator pedal.

    Fill it until the compressor stays on and quits cycling. Once the compressor stays engaged on it's own its probably "full enough" (as long as you're getting cold air)..
     
  10. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
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    Actually, no, you do not need to have the A/C running to suck in the first can, only later ones. If you draw a good 30 inch vacuum, the entire first 12 oz can should go right in without the motor running. If it doesn't, set it in a small bucket of hot water and it will.

    Your method of filling until the compressor stays engaged is faulty and perhaps dangerous. Overcharging is dangerous and can damage the system. You fill the system by putting in the proper weight prescribed by the manufacturer, while monitoring high and low pressures to be sure they are in the right range. And you also monitor the vent temperature to see if it's in the range that it should be.
     
  11. GDawgie

    GDawgie Member

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    I must add to this thread on something I heard and from more then one repair shop, I have a 1994 Dodge Grand Caravan LE and it never blows real cold air, on real high humidity days it does it's job removing the moisture and it feels cooler coming out of the vents but on normal warm days the air comes out in the 60's to 70's, I had it checked at three different shops at different times, all three said that is about as good as your going to get with a 94, it was the change over year from R12 to R134a and the design of the system is basically a retrofit from R12 to R134a and the system was not optimized for R134a so you'll never get the super cold air out of the vents like newer models.
    Now I had 3 different shops tell me the same thing, so I have justed decided to live with the fact that the AC in this year model sucks, just like the headlights, they stink, I can do better with a flashlight I get out of a Cracker Jack box:) So for those of you who have ice cold air coming out of the vents of your 94 I say "according to the mechanics" that your one of the lucky ones.
     
  12. John Wood

    John Wood Well-Known Member

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    This is true for most of the older mini-vans that only have the front air option. If these have been sitting in the sun, there is a substantial amount of heat to remove and it can take 20 minutes to get decent cooling. If the vehicle has been parked in a garage, usually you can get a fairly quick cool down.

    My 96 G Voyager is the same way. It always passes the diagnostic cool down test (a feature that came about in 1996 and later vehicles), but I am not impressed by the amount of time it takes to cool the interior. I am about to experiment with the alternative refrigerant R-152 since the reports I have read from the few that have converted do show some improvement. There is not a lot of information out there yet but those who have tried it on a R134a system say you can get about 4 to 5 degrees improvement plus quicker cool down.
     
  13. valiant67

    valiant67 Rich Corinthian Leather
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    Odd, because the 1994 AC was redesigned from the earlier R12 vans. The first on the "new" minivans like the 1991 Grand Voyager I used to own had a smaller radiator and the AC condenser side by side, each with their own fan. Sometime around 1993/1994 they changed to a more conventional full width radiator with the condenser in front of it. I always assumed that was because of the change to R134a but I suppose it could have happened before.
     
  14. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
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    1994 was the first full year of R134a in Chrysler products, and that system should have been optimized for it. Definitely if you have more glass area, it will take longer to cool down. But my wife's 97 Camry can freeze meat, it's so cold, and so can my 93 Daytona that's been converted to R134a.

    A lot of the success depends on being meticulous and thorough at each step of the way, including the amount of oil and freon, and how long the vacuum was pulled.
     
  15. Rick Anderson

    Rick Anderson Well-Known Member

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    R12 and R134a have different properties, like condesation temperature and evaporation pressure, so R134a needs a bigger condenser then R12, but a smaller evaporator, to perform at the same level.

    Like Valiant said, my '91 van had a half width condensor, and I checked into when I retrofitted my van to R134a, the R134a vans switched to a full width condenser.

    What my '91 van and many other years had, was a pressure controlled variable displacement compressor. These compressors had adjustable valves and were notorous for getting out of calibration and NOT being able to pump at the correct volumes and pressures when that happened. There was a warning after warning I read that said NOT to touch the adjustment screws, if you did, likely the compressor would never be able to work right again.

    Could that be your problem GDawgie? Do you have one of the variable displacement compressors in your '94 van? Over time it got out of calibration and is NOT pumping enough? Notice Chrysler, nor do I think anyone, uses these kinds of compressors anymore.
     
  16. Aictually i was not having any idea about this..... Really, this is useful information. it will be very useful for me . Thanks for providing information regarding this...
     
  17. JTE

    JTE Well-Known Member

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    Well it's winter now and I need to know how to recharge my "New Posts" button.
     
  18. GLHS60

    GLHS60 Well-Known Member

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    LOL!!

    Me too.

    Thanks
    Randy
     
  19. RMS_Voyager

    RMS_Voyager Member

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    LOL, much easier than you think, under the hood, you'll see the A/C compressor, follow the metal tubes comming off of it, there will be two metal lines which have nipples covered with black screw off caps...whatever year van your driving the upper and lower will be in seperate locations. The smaller nipple is the one you need to pump the coolant in to. Head on down to your local Big Lots and grab a can (usually locked in a glass display case) its a tall can, with a hose that has a pressure gauge attatched to it. the can usually runs around 20 dollars, its called Glacier, or something like that. You don't have to worry about which nipple to plug it on to, it only fits on to one of the two nipples, (i guess an idiot proof feature) you may have to do some scraping around the nipple, as gunk builds up over 10-15-20 years, to get it to fit properly, takes a bit of muscle to get it on there sometimes. after that, start the car, switch on the air con to max full blast, and simply press the button on the canister while holding upright, occasionally tilting it to one side. some of the coolant may escape from the can by doing so, but this is normal. You probably wont notice any difference in temperature immidiately, but once you start driving around normally, it should be ice cold. as far as any leaks go, i would have to say its leaking from one of the two nipple valves...usually where my leaks always happen, ive had 7 of these things, plymouth dodge and chrysler minivans, all have the same problems.
     
  20. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
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    Servicing A/C is not as easy as described above. You need to know what you're doing, you need to fix all leaks first, you need to draw a vacuum before charging an empty system.
     

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