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

[Konstantin]

When something fails in AC system you can't check if it was contaminated or not. But what you could do is connect nitrogen tank and purge the system. I work on my thermoking reefer quite a bit and I did it couple of times, not because of metal shavings, but because that is what you have to do if ac system was opened for a while. After you evacuate and charge.