Can I use R134 to "test" R12 system for leaks?

http://www.youtube.com/watch?v=py_2yOCgKZI&feature=youtube_gdata_player
Notice the bubbles in the oil flowing through the sight glass.

 

As another certified A/C tech, you don't understand what is going on here. No One is mixing anything or running a compressor with the improper oil. So nothing wrong has been sugested.

 

We can go back and forth for years... I've shown what happens. And regardless it still mixes to some extent.

 

Fair enough.

 

Hi folks,

Thanks to everyone for the info and education. I have decided the best route is to check for the leak with Freeze 12, remove it, replace accumultor and orifice tube and refill with R-12.

Here is one more question. Since I'm changing the accumulator I normall add about an ounce of oil to the system. Does it matter if I add it to the suction line going back to the compressor or if I just add it to the accumulator?

Also, should I add an ounce of mineral oil, Ester oil, or something else? I'm assuming either of the two oils I mentioned would be fine, but I don't like to assume.

Best,

Ranger
Aiken, SC

 

Accumulator and only mineral oil if your using r12