MALFUNCTION
CAUSE
REMEDY
Worn packing seals
Replace packing seals
Broken valve springs
Replace springs
Belt slippage
Tighten or replace belt
Worn or Damaged nozzle
Replace nozzle
Fouled discharge valve
Clean valve assembly
Worn or plugged relief valve on pump
Clean, Reset, and Replace worn parts
Cavitation
Check inlet lines of pump for restrictions
or leakage
Unloader
Check for proper operation
High Humidity
Reduce oil change intervals
Worn Seals
Replace seals
Worn bearings
Replace bearings, Refill crankcase with
recommended oil
Cavitation
Check inlet lines for restrictions and/or
proper sizing
Worn packing
Replace packing
Inlet restriction
Check system for stoppage, air leaks,
correctly sized inlet plumbing to pump
Accumulator pressure
Recharge or replace accumulator
Unloader
Check for proper operation
Cavitation
Check inlet lines for restrictions and/or
proper sizing
Pressure drop at gun
Restricted discharge plumbing
Re-size discharge plumbing to flow rate of
pump
Worn plungers
Replace plungers
Worn packing/seals
Adjust or replace packing seals
Excessive vacuum
Reduce inlet vacuum
Cracked plungers
Replace plungers
Inlet pressure too high
Reduce inlet pressure
Wrong Grade of Oil
Giant oil is recommended
Improper amount of oil in crankcase
Adjust oil level to proper amount
PUMP SYSTEM TROUBLESHOOTING CHART
High Crankcase
Temperature
Excessive leakage
Rough/Pulsating
Operation with
Pressure Drop
Noisy Operating
Water in Crankcase
The Pressure and/
or the delivery Drops
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