If your a/c is overloaded with oil it will start knocking before it dies. That 'green" stuff you saw was dye. An ultraviolet light will pick up leaks in the system by the dye leaking out along with your R-134.


I work on A/C systems most of the time in the summer. I have seen 15 year old cars still blowing cold on the factory R-12 charge. Refrigerant doesn't really go bad. But the system that holds it eventually develops a slow leak. If you need an A/C recharge then you obviously have a leak however small it maybe. Most shops will recharge your A/C along with a shot of dye. And a few weeks later your A/C will stop blowing cold compressor isn't kicking on. You bring the car back in they find a leak, you pay to fix the leak and recharge the A/C again.

There is no way to get all the oil out of an a/c system unless you removed every single part. An A/C recharge machine can evacuate the system using a vacuum, even though there is oil pulled out at this time there is still oil in your system. There is only one way to see if your compressor is junk. Fix the leak, recharge the system, and see how it does.

 

So you're saying there's not much chance the system is actually running dry? Makes sense I guess. But I wonder why *no* oil came out at all?

 

why did you put R12 into an R134a system?

 

No, it's R-12a. It's some special blend of gasses made for R-134 systems. I dunno.

RED TEK® 12a, a HC-based refrigerant from Thermofluid Technologies, is a blend of environmentally safe hydrocarbon fluids designed as a direct replacement and retrofit refrigerant option for replacing R134a and R12 refrigerants in automotive air conditioning and refrigeration systems. 12a operates at lower head pressures and offers improved cooling properties and performance verses R134a and R12.

RED TEK® 12a possesses similar volumetric refrigerating effects to R12 or R134a refrigerants. Operates at lower head pressures and offers improved cooling properties, performance and energy efficiency verses R12 or R134a. Can be used effectively in R12 or R134a refrigeration systems without major "retrofitting."

Ok, the system sticker says I need 7oz of oil. I put 2 cans in, which means 4 oz of oil. I used the tester thing, and now some green oil comes out onto the tester. However, it doesn't really indicate how much is in the system well. It's just a clear plastic tube thing with like some fibrous almost paper stuff in it. You push it on the valve and some of the refridgerant vents through it, and oil goes with it. The paper stuff soaks up the oil. It says you're supposed to see the paper full of oil if you have enough oil. Mine is only like half full.

But, I'd think technique would come into play. It says that you push it on 2-3 times. But it doesn't say how long. I gave 3 really short squirts. Maybe they hold it on for longer. I dunno, it doesn't say how long. Really wacky way to check a fluid level.

I know I lost a lot of oil, cause I saw it on the driveway all winter. I thought it was coolant until I realized the AC had stopped working. Wherever the leak is, it seems to have been letting the oil out too.

So how much oil do I put in? If I put too little, I burn out the compressor. If I put too much, you wreck the compressor because of fluid slugging. And I'm shooting blind here...

The compressor has an odd noise to it. Kind of a mechanical whirring. Not sure if that's normal. I don't think I've ever heard it coming from a compressor before, but then I've never listened that closely before.:dunno:

 

you put 7 oz of oil in!?

most of the oil stays in the dryer, condensor, and compressor. you definately werent dry. Too much oil can cause the AC to blow warm or be inoperative.