SECTION 6
Trouble
Low discharge pressure
Water in the crankcase
(lubricant appears milky)
Rusty valves
and/or cylin ders
Excessive vibration
QT/QTS Series
2022208700, September 2018
Probable Cause
•Restricted inlet
•Defective compressor valves or valve unloading mechanism
•Leaks in the compressed air distribution system at fittings, connections,
etc.
•Unloader pilot valve defective or set wrong
•Pressure switch defective or set wrong
•Drive belt slipping
•Incorrect speed
•Worn piston rings or loose piston
•Leaking head gasket
•Drain valve open
•Defective pressure gauge
•Pressure relief valve leaking
•Clogged intercooler
•Compressor incorrectly sized for the alti tude it is operating at
•Piston rings not seated; allow 100 hours at full pressure
•Compressor does not run long enough to get hot and vaporize the liquids
squeezed out of the air during compression (compressor may be too large
for application)
•Incorrect or inferior grade of lubricant
•System pressure leaking back through dis charge valve
•Compressor operated too infrequently
•Compressor does not run long enough to get hot and vaporize the liquids
squeezed out of the air during compression (compressor may be too large
for application)
•Compressor not properly prepared for stor age
•Discharge line from compressor head is pointed upward allowing con
densation to drain back at shutdown
•Incorrect speed
•Compressor valves not functioning prop erly
•Loose pulley/sheave
•Compressor, motor or engine not secured tightly, or tightened into a
bind
•Foundation or frame inadequate
•Piping inadequately supported or tightened into a bind
•Excessive discharge pressure
•Compressor feet may need to be leveled with shims
41
TROUBLESHOOTING
Quincy Compressor
Need help?
Do you have a question about the QT Series and is the answer not in the manual?
Questions and answers