Product Manual

Owner’s Manual for Dry-Prime Diesel Trash Pumps 49
Maintenance
7. For seals, bring the gland and gasket against the
face at the seal chamber and tighten the bolts
evenly.
Impeller Lockscrew Installation
Impeller lockscrews are always right hand socket head
capscrews. Stainless steel lockscrews are supplied with
Loctite 262, which should be applied to lockscrew threads
and shaft prior to installation.
First determine the size and material of the lock, then
torque to the appropriate value listed in the table below.
Lubrication
Do not lubricate the impeller lockscrew or tapped hole,
between the lockscrew and impeller washer, or between
the impeller washer and impeller. Verify parts are clean
and dry; however, it is not necessary to remove the
protective coating from the screw. Lubricated bolts can be
overstressed with the torques indicated.
NOTE: Do not use the lockscrew to install the impeller.
NOTE: Lockscrew failure can damage the impeller and
volute. The impeller screw must be of the best material,
properly forged and machined to rigid specifications not
available from local suppliers. Purchase only lockscrews
available from Generac Power Products for assurance of
quality.
Impeller Lockscrew Removal
1. Break the impeller lockscrew loose with a breaker
bar.
NOTE: Care should be taken when removing lockscrew
to prevent damaging the screw head.
2. If the breaker bar will not loosen the impeller
lockscrew, apply heat to the lockscrew for 2-4
minutes. Do not exceed 400°F (204°C).
3. Allow lockscrew to cool and remove with a breaker
bar.
Frame Disassembly and Assembly
Disassembly
1. Remove the deflectors from the shaft.
2. Remove the drive end shaft key.
3. Remove the capscrews from the bearing cover or
drive end bracket.
NOTE: Grease lubricated frames have a single lip seal
at the drive end pump ends. If the lip seals are to be
saved, the shaft should be cleared of burrs or sharp pro-
trusions which would cut the seal. If the seals are
removed or replaced, refer to Figure 4-2 or Figure 4-6
for orientation of the lips. Paired seals have a grease
passageway between them and are arranged so that the
grease will move through the inner and outer seal.
4. Slide the bearing cover or drive end bracket off the
shaft. Remove the capscrews from the pump
bracket. Slide the pump bracket off the shaft.
5. The shaft and bearings can now be removed by
pressing on the drive end of the shaft.
6. Remove the bearings from the shaft with a bearing
puller. If the bearings are to be saved, keep them
absolutely clean. If contaminated, wash only in
clean fluid.
NOTE: Never hammer the shaft or parts attached to the
shaft or you will damage both the shaft and the bearings.
Table 5 - Lockscrew Torque Values
Size
Torque for Stainless Steel Lockscrew (nonmagnetic)
302, 303, 304, 316 Series
.38- 6UNC 20 ft-lbs (27 Nm)
.50-13UNC 40 ft-lbs (54 Nm)
.62-UNC 90 ft-lbs (122 Nm)
.75-10UNC 135 ft-lbs (183 Nm)
1.00-8UNC 265 ft-lbs (359 Nm)
1.12-7UNC 360 ft-lbs (488 Nm)
1.25-7UNC 510 ft-lbs (691 Nm)
1.50-7UNC 875 ft-lbs (1186 Nm)
WARNING
Risk of Burns. Take care when applying heat
to the lockscrew. Failure to do so could result
in serious injury.
(000276)