My 01 Screw 4,6L (230,000) ac compressor has gotten pretty loud (still blows very cold air). Not the sound of a failing clutch, but the loud pumping sound if that makes sense. (can hear several feet away from truck) Especially hot.

I'm going to replace the compressor, accumulator and orifice tube. If I pull the tube and I don't see any debris or sludge do I need to flush?

My understanding is you can't flush the condenser or the line with the muffler. That only leaves the evaporator. I can get a flush gun from autozone and the flush. I'm just trying to figure out in this case is it necessary?