Symptom
Cause
Remedy
Pump assembled incorrectly
Compare pump assembly to instruc-
tion manual
Higher solids concentration than
specified
Analyze pumpage and correct or
change pump wet end materials to
harder composition
Excessive leakage from stuffing box
Packing gland improperly adjusted
Tighten gland nuts
Stuffing box improperly packed
Check packing and re-pack box
Worn mechanical seal parts
Replace worn parts
Overheating mechanical seal
Check lubrication and cooling lines
Shaft sleeve scored
Re-machine or replace as required
Packing has short life
Pump run off design point
Check head and flow, AF’s should
normally be run between 75% and
125% of BEP
Shaft/shaft sleeve worn
Replace shaft or shaft sleeve if nec-
essary
Packing gland not properly adjusted
Replace packing and readjust gland
as specified in the operating manual
Packing not properly installed
Check packing manufacturer's in-
structions
Pump not assembled correctly
Compare pump assembly to instruc-
tion manual
Bearings run hot and or fail on a reg-
ular basis
Lubricant level
Be sure the oil level is at center line
of sight glass
Improper lubricant
Check lubricant for suitability
Not lubricated enough
Increase frequency of grease lubrica-
tion
Broken or bent impeller vanes
Check impeller dimensions and vane
layout
Excessive shaft misalignment
Check shaft run-out and consult fac-
tory
Inadequate lubricant cooling
Check pumpage temperature and
add oil cooling system if necessary
Axial thrust or radial load higher than
bearing rating
Calculate bearing life for make and
model bearing
Improper coupling lubrication
Check coupling lubrication schedule
in manufacturers installation, opera-
tion, maintenance manual
Coupling out of balance
Check pump and drive component vi-
bration levels, rebalance coupling if
necessary
Suction pressure too high
Check liquid levels and static suction
pressure
Bearing incorrectly installed
Check bearing orientation to sectional
drawing
Impeller out of balance
Check pump vibrations, if necessary
rebalance impeller
Excessive shaft deflection
Check shaft diameter, sag and deflec-
tion, consult factory
Pump run off design point
Check head and flow, AF’s should
normally be run between 75% and
125% of BEP
Lubricant contamination
Inspect oil or grease for contaminants
7.1 Pump Troubleshooting
62
Model AF (42"/1200mm/54"/60"/66") LM/LMR Bearings Installation, Operation, and Maintenance Manual