Product Manual

50 Owner’s Manual for Wet-Prime Trash Pumps
Maintenance
Rotating Assembly
1. Wash the impeller threads with shop solvent. Be
sure the threads in the impeller and on the shaft
are completely clean and free of all burrs or other
debris.
2. Several measurements need to be taken to
determine if any shims are needed to achieve the
proper backvane clearance. Using an adjustable
square, measure the distance from the end of the
sleeve to the surface of the backplate. Compare
this dimension with a measurement taken from the
impeller hub to the backvane surface to determent
how many shims are needed to achieve the proper
backvane clearance.
3. Rotate the shaft by hand to install the impeller,
paying close attention not to cross-thread.
NOTE: Be certain that the drive end of back side of the
impeller is perpendicular and lined up to the shaft
threads.
4. When the impeller bottoms on the sleeve, the
backvane clearance should be checked with feeler
gauges to obtain 0.022-0.038 in. (0.558-0.965 mm)
backvane clearance. Adjust the impeller shims if
necessary. Once the backvane clearance is within
specification a shaft wrench can be used to tighten
the shaft into the impeller.
5. The shaft wrench is designed to be used on the
drive end of the frame shaft. Tighten the impeller
by rotating the shaft counter-clockwise and then
back clockwise rapidly until the wrench hits the
workbench or other solid surface. This should be
done two to three times to be sure the impeller is
seated against the sleeve.
NOTE: DO NOT OVERTIGHTEN THE IMPELLER.
6. After the impeller is installed, install the lockscrew
(with impeller washer) with a permanent thread
locker, such as Loctite® 262 or equivalent. Tighten
to the torque listed in the chart.
Figure 4-8. Impeller Components
1. Bearing (pump end) 2. Retaining ring
3. Shaft shoulder 4. Shaft
5. Bearing (drive end) 6. Lip seal
7.
Snap ring
Table 5 - Impeller Lockscrew Torque Values
Size Torque
.50-13UNC 40 ft-lb (4 inch pump)
.62-11UNC 90 ft-lb (6 inch pump)
1
2
3
4
4
5
.030" ±.008
01658