How to check if I have metal in the AC system?

[walterk]

Purging with Nitrogen is done on a clean system after a pressure test when you evacuate Nitrogen through the suction line, but flushing with an AC solution is a bit tricky as all the lines have to be removed to avoid pushing contaminants down to other components, and each component is flushed individually. Considering the scope of this job, I would do it only if there is a clear indication that the system is contaminated with impurities/solids. So first, I would see how contaminated is the oil coming out of the compressor when you remove it. Then, you can cut the filter-dryer open and see how bad it is inside if you want to confirm that the system is contaminated. Based on these, you will know how serious the problem is and if you need to flush or just purge. Please post the pictures if it is really bad for educational purposes.