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Old 08-06-2001, 07:55 AM
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107 A/C presures advice?

I recently recharged my a/c with 2.2lbs of r12. I put in enough just to where the site glass was running clear. I also have gauges that measure the low and high side.
Can someone tell me what the pressures should be?

With all this done I still do not have very cold air. The aux fan is working fine. I have shut the water valve to make sure that I am not getting hot air mix.

I need to know if the compresser is working fine or if I need look at something else.
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Old 08-06-2001, 08:45 AM
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If you charged to a clear sight glass, the amount of charge or compressor is probably not your problem. I would look toward a vent door opening to outside air, or some other ducting control problem.

The compressor typically pumps okay or it doesn't. If the compressor is pumping, it's not something that will cause your problem. Your low side pressure will typically be around 30PSI with a good charge. The high side will vary, but could be around 190 to 250PSI.

Good luck,
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Old 08-06-2001, 09:36 AM
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thanks larry for the quick reply. I do have a question regarding some of the other support components like the drier and the expansion valve. What effect does these devices have in the system? Like the the expansion valve, If it is faulty would that contribute to lack of cooling?

I just took a reading and found it to be 40 low and 220 high after running it for about 15 min in park. I am only getting a 10 deg drop from ambiant. I have made sure that the hot water valve is closed off.

I did notice that If I open the hot water valve then I get heat from the drivers side vent and defrost vent. I never notice cool air from these vents

I do not have a manuel so i am a bit confused about what levers control what except that the two outside levers control a vacume switches.... Right one for water valve/ left one for outside air servos. I know this because the levers had come off the switches and were causing the water valve to stay open as well as having to replace the digraphms on the air flaps. I can figure all this out with time.

I would like to know how I can be sure that the expansion valve is working properly. What indications do I look for?
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Old 08-06-2001, 02:28 PM
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Your pressures sound good and with a pressure difference like that, your expansion valve is probably okay, if it goes bad it will not act as an orifice, thus producing a pressure drop.

I still think that with pressures such as this, the a/c portion itself is not the problem, the problem will be related to air flow across the evaporator. I'm sorry that I don't know more about your particular chassis to offer more detailed advice.

Keep checking those duct doors and such,

Good luck,
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Old 08-06-2001, 10:33 PM
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According to my official reproduction Owner's Manual (tongue planted firmly in cheek), the ac knob on the lower right of the console will start recirculating air at 2/3 switch travel to the right (clock-wise). There will be a small amount of fresh air let in and the fan will switch to low speed operation.

For rapid cooling the manual recommends turning the ac switch and the blower switch to the left of it, clockwise to stop (full on). It also recommends moving levers 2 and 3, counting from left to right, to the "closed" position. It then recommends moving the lever above the radio to the open position, along with the levers to the left-most of the driver and the right-most of the passenger.

Hope this helps.

Recently bought the manual at Adsit if you are looking for one.

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Old 08-07-2001, 08:34 AM
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I bought the CD version of the manuel and found that I had a lever that controled flaps was loose. I then placed my gauges on the system just to check the pressures again to be sure. Everything was working great. Then it happened..... Stupid cheep pressure gauge came apart. Lost all my r12 (bummer)

Back to square one. I am now going to replace my drier and convert to 134a and try it again. 102 deg today. I am going to be driving my van.
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