Giant LP460, Operating Instructions/ Repair And Service Manual

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7
PUMP SYSTEM MALFUNCTION
MALFUNCTION CAUSE REMEDY
The Pressure and/ Worn packing seals Replace packing seals
or the Delivery Broken valve spring Replace spring
Drops Belt slippage Tighten or Replace belt
Worn or Damaged nozzle Replace nozzle
Fouled discharge valve Clean valve assembly
Fouled inlet strainer Clean strainer
Worn or Damaged hose Repair/Replace hose
Worn or Plugged relief valve on pump Clean, Reset, and Replace worn parts
Cavitation Check suction lines on inlet of
pump for restrictions
Unloader Check for proper operation
Water in crankcase High humidity Reduce oil change interval
Worn seals Replace seals
Noisy Operation Worn bearings Replace bearings, Refill crankcase
oil with recommended lubricant
Cavitation Check inlet lines for restrictions
and/or proper sizing
Rough/Pulsating Worn packing Replace packing
Operation with Inlet restriction Check system for stoppage, air Pres-
sure Drop leaks, correctly sized inlet
plumbing to pump
Accumulator pressure Recharge/Replace accumulator
Unloader Check for proper operation
Cavitation Check inlet lines for restrictions
and/or proper size
Pump Pressure as Restricted discharge plumbing Re-size discharge plumbing to
Rated, Pressure flow rate of pump
Drop at gun
Excessive Worn plungers Replace plungers
Leakage Worn packing/seals Adjust or Replace packing seals
Excessive vacuum Reduce suction vacuum
Cracked plungers Replace plungers
Inlet pressure too high Reduce inlet pressure
High Crankcase Wrong Grade of oil Giant oil is recommended
Temperature Improper amount of oil in crankcase Adjust oil level to proper amount