N62B (legacy/predecessor compound two-stage)

Inspect cylinder head, valves (suction and discharge), and valve plates for wear, cracking, or leakage — these are the most common wear points on reciprocating compressors

Check piston rings and cylinder liner for wear, scoring, or blow-by; measure clearances against manufacturer tolerances

Inspect connecting rod bearings, main crankshaft bearings, and wrist pin bearings for wear and proper oil clearance

Verify crankshaft oil seal integrity and inspect for oil leaks at all shaft seals and gasket surfaces

Check capacity-control (unloader) mechanism — solenoid valves, unloader rings or lifters, and actuating pistons — for correct operation at all capacity steps

Inspect oil separator, oil pump, oil filter, and oil cooler; change oil and filters per service interval; verify oil pressure is within specification

Check safety devices: high- and low-pressure cut-outs, oil differential pressure switch, motor overloads, and high discharge temperature cut-out for correct set-points and operation

Inspect belt drive or coupling alignment; check belt tension and sheave/pulley condition if belt-driven; verify motor mounting bolts are torqued correctly