Great Plains 3P300 Operator Manual User Manual
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Section 5 Maintenance and Lubrication
3P200 and 3P300 Three-Point Sprayer 500-103M
3/6/06
Great Plains Mfg., Inc.
Centrifugal Pump Assembly
Figure 5-2
11591
If the pump is leaking, before removing it from the sprayer,
run the pump with adequate water in the tank to diagnose
the actual pump problem. If fluid leaks out between the
front suction housing (#5) and the rear volute housing
(#8), the housing gasket may be dried out. Give the gasket
(#6) adequate time to absorb moisture and swell up. If
necessary, retighten the volute housing (#8) by alternating
on opposite sides until all nuts (#9) are torqued to 16 - 18
ft.-lbs. It is a good practice to apply grease to both sides of
the gasket (#6) to prevent shrinkage.
If seal replacement is required:
1.
Disassemble pump and clean all components.
2.
Assemble the ceramic ring seat of the mechanical
seal (#7) into the volute housing (#8) of the pump.
Make sure the ceramic seat is positioned square into
the volute housing.
3.
Clean off any grease or dirt from pump shaft (#10) and
dry the shaft so the rubber bellows on the mechanical
seal will adhere to the shaft properly when assembled.
4.
Bolt up the pump input bearing housing (not shown) to
the volute housing (#8) using bolts(#2),(#3) and (#4)
with spacers (not furnished) for alignment and assem-
bly of the shaft seal.
5.
Assemble the seal (#7) without its spring, on the pump
shaft by pushing on the inside rubber portion of the
seal using water as the lubrication. The graphite seal
face should touch the white ceramic seat face. The
rubber bellows adhering to the pump shaft should not
protrude more than 1/16" beyond the stainless steel
ring located on the impeller side of the seal.
6.
Assemble the seal’s spring and the impeller, being
careful not to move the mechanical seal that has been
positioned on the pump shaft. Torque the impeller bolt
(#1) 16 - 18 ft./lbs.
7.
Remove the three bolts and spacers. Using gun
grease, lubricate the gasket (#6). Assemble the gas-
ket (#6) and suction housing (#5) using bolts, flat
washers and locknuts. Torque nuts 16 - 18 ft./lbs.