Working on my friends 77 Regal... This was the car with the bad superheat switch. Definitely no good. 60 psi in the system static and no conti uity toground from the switch. Replaced switch, now we have continuity across the aftermarket switch! Great.....start the car and its low on charge- clutch is cycling on and off like mad. Ok, next is to reclaim system and check/ replace orifice tube. Take the line apart and no tube! Cant be. I take a piece of wire and there's Definitely something in there but it down deep in the tube. Get a flashlight and a mirror, and sure enough the orifice tube was installed backwards! Great, now what? After alot of cussing I was able to get it out with a small needle nose pliers. Whew!! You can see where the orifice is bent because it was jammed where the tube make a 90 degree bend. So new orifice, vacuum it down and slam 4 cans of 134A in it. System take 60oz of 12, so 45oz of 134A. The can I have are 12oz, so that's 48. I'll likely lose an oz or two purging the gauge lines. How it was- How ita supposed to be-
That's the dirtiest orifice tube I have ever seen, that entire system should be flushed. When systems are converted from R12 to R134 there is a solvent that should be flushed through all components to remove all the R12 oil since the chemistries are not compatible and the receiver drier should also be replaced. The physics changes also since a molecule of R134 is 40% smaller then a molecule of R12. They make a thing called a variable orifice tube for that purpose. A variable orifice tube will lower the vent temp at least 8 degrees. https://www.ebay.com/itm/1753722552...4MujklnEGGzMNKTUyWF96YIIpxYg|tkp:BFBM4OTIzepi
Thanks, for showing us all this Awesome information. Things seem to get complicated quickly with our TOYS...!!! I need all the help Ican get with this stuff. Respectfully, Jim Jaeger Semper Fi
