Carrier 19XL - Manual (Page 211)

As a minimum, the following maintenance is required.
1. At least once a year, disconnect the vent piping at the valve outlet and carefully inspect the
valve body and mechanism for any evidence of internal corrosion or rust, dirt, scale,
leakage, etc.
2. If corrosion or foreign material is found, do not attempt to repair or recondition. Replace the
valve .
3. If the machine is installed in a corrosive atmosphere or the relief valves are vented into a
corrosive atmosphere, make valve inspections at more frequent intervals.
Compressor Bearing and Gear Maintenance
The key to good bearing and gear maintenance is proper lubrication. Use the proper grade of
oil, maintained at recommended level, temperature, and pressure. Inspect the lubrication
system regularly and thoroughly.
To inspect the bearings, a complete compressor teardown is required. Only a trained service
technician should remove and examine the bearings. The cover plate on older compressor
bases was used for factory-test purposes, and is not usable for bearing or gear inspection. The
bearings and gears should be examined on a scheduled basis for signs of wear. The frequency
of examination is determined by the hours of machine operation, load conditions during
operation, and the condition of the oil and the lubrication system. Excessive bearing wear can
sometimes be detected through increased vibration or increased bearing temperature. If either