Giant GP7142, Operation Manual

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7
PUMP SYSTEM MALFUNCTIONS
MALFUNCTION CAUSE REMEDY
The Pressure and/
or the Delivery Drops
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
Cavitations Check suction lines on inlet
of pump for restrictions
Unloader Check for proper operation
Water in Crankcase High Humidity Reduce oil change intervals
Worn Seals Replace seals
Noisy Operating Worn bearings Replace bearings, Refill
crankcase oil with recommended
lubricant
Cavitation Check inlet lines for restrictions
and/or proper sizing
Rough/Pulsating
Operation with
Pressure Drop
Worn packing Replace packing
Inlet restriction Check system for stoppage
air 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
Drop at gun Rated,
Pressure
Restricted discharge plumbing Re-size discharge plumbing to flow
rate of pump
Excessive
Leakage
Worn plungers Replace plungers
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
Temperature
Wrong Grade of Oil Giant oil is recommended
Improper amount of oil in crankcase Adjust oil level to proper amount
GP7142 Torque Specifications
Position Item# Description Lubrication Info Torque Specifications
1 07600 Crankcase Molycote/Cu-Paste
10 22706 Hexagon Screw 33 ft.-lbs. (45 Nm)
12 07109 Drain Plug 59 ft.-lbs. (80 Nm)
24 13182 Connecting Rod
Assembly
30 ft.-lbs. (40 Nm)
30A 07225-0100 Hexagon Screw 89 in.-lbs. (10 Nm)
32 07624 Radial Shaft Seal Loctite 403
36A 07667 Plunger Connection 33 ft.-lbs. (45 Nm)
36C 07664 Tension Screw Loctite 243 30 ft.-lbs. (40 Nm)
49 13159 Stud Bolt Loctite 270
49A 13160 Hexagon Nut 103 ft.-lbs. (140 Nm)
58 06682 Plug 107 ft.-lbs. (145 Nm)