Mechanics

AC PROBLEMS

2002 Buick Rendezvous

This Buick has 46K miles and besides the AC problem that I am experiencing now has performed flawlessly. I have taken this car to the mechanic to get the AC checked out and what they told me was wrong, was the AC compressor but they said it would cost $1200 to fix $700 for the parts and $500 for the labor. I got a 2nd estimate with similar rates but was told I could by it myself for cheaper and they would put in it for me. I was able to buy the part myself from advanced auto parts and get them to put it in for me. It took about 2 hours for them to put it in and the AC worked for about 2or 3 days and then began to run hot. I took it back and the mechanic said it could possibly be a leak in one of the pressure valve. That was replaced and two cans of Freon were added. Again it worked for about 2 days and began to run hot. I took it back again and this time he suggested that it could be the evaporator coil? He said it could possibly be fixed by putting evaporator leak stopper. We loaded that and put cans of Freon and it stayed cool in the car for about 2 ½ hours. It is now running as if we never did anything to the car. Please help?
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Qball3404
July 1, 2007.




I have the same car. Ill simplify this for you. Heres what is happening.R134a has smaller molecules than R12. Whan you dont use the AC in the colder months what happens is the seals dry up and shrink causing your R134a to slowly leak out. Its highly unlikely that your compressor was defective. Ive seen cars way older in good shape. When you brought it to that shop did they evacuate, pressure check then recharge it. The way I do it is evacuate the system by putting it into a vaccuum for 30 mins then close the valve the blue one low pressure side. Then observe the gauge to see if theres any leaks then spray all connections with soap water. If it bubbles then theres a leak. Then when the leaks fixed, usually an O ring. Then your ready to recharge the system. The right way is to weight the R134a you put on on a digital scale that reads negative weight. Your underhood sticker will tell you how many LBs or KGs of R134a it needs. With the engine running you then fill it. Increase the RPMs to around 2500 to get it circulating. When you have it filled your vent temperature should be around 39 to 43F. Hope this helps

Tiny
Mikebur73
Jul 6, 2007.


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