2 1. Cylinder
Not Scheduled. Check cylinder walls for wear and scoring. Measure inside diameters at top, bottom, and
middle in two directions, 90 degrees apart. If cylinder is out-of-round or oversized, rebore cylinder.
Not Scheduled. Check piston for wear. Check clearance with micrometer. Examine rings for tightness
and fit. Replace if necessary. Check piston rod for trueness and scoring or wear. Renew or replace as
23. Connecting Rod
Not Scheduled. Check for distortion or bending. Check bearing bolts and nuts for damage and replace as
24. Intake and Discharge Valves
Not Scheduled. Inspect valves and seats for scoring and proper seating. Clean any deposits off of seats and
valve plates being very careful not to scratch the surfaces. Lap valve seats if there are any imperfections.
Deposits on the valves indicate a dirty intake, the wrong type or excessive oil, or a leaking valve or valve
Rotary Screw Compressors
25. Air End
Not Scheduled. Check condition of rotors and bearings. Replace if worn or if compressor efficiency had
26. Oil Reservoir and Separator
Monthly. Drain condensation from bottom of oil reservoir.
Annual. Check condition of separator element and service or replace if oil consumption is excessive.
27. Oil Filter
Annual. Replace or clean oil filter as required.