[carnut]

The clutch coil is an electro-magnet, If the magnet is weak, then its hammer time!! Also if the air gap is too wide between the coil and clutch, the current cannt span the gap and again, hammer time. The clutch comes off with a specific puller. A spanner wrench of sorts that prevents clutch rotation as the puller threads into the clutch face. The system does not need evacuation to replace the clutch assembly. Shops will normally replace the compressor as an assembly to lessen comebacks and also to be able to warranty the assembly rather than just the clutch. The other rationalle is the compressor's as old as the clutch and why do it twice too soon.