Step 3 – Check for contamination.If old oil was blackened, replace expansion valve and receiver-drier. If clean, perform oil balancing to prevent noise from oil starvation.
Step 4 – Mount new compressor.Hand-tighten bolts in cross sequence, then torque to manufacturer specs. Set belt tension: new belt = 500-560 N·m; used belt = 300-400 N·m.
Step 5 – Pressure tests.Run positive pressure test at 1.4-1.6 MPa for 30-40 min (leak check). Then vacuum test at -0.08 to -0.1 MPa for 30-50 min (seal check).