Gorman-Rupp Pumps U3B65S-B 1292028 and up - Manual (Page 31)

OM-05664 SUPER U SERIES
MAINTENANCE & REPAIR PAGE E - 7
move the pump casing drain plug (3) and drain the
pump. Clean and reinstall the drain plug.
Remove the back cover nuts (23) and pry the back
cover and assembled wear plate from the pump
casing (1).
NOTE
An alternate method of removing the back cover
from the pump casing is to remove the back cover
nuts (23) and two diagonally opposing locking col­
lars (26). Install two 1/2-13 UNC2B x 2 inch long
screws in the tapped holes in the back cover and
use them to press the back cover out of the pump
casing.
Inspect the wear plate and replace it if badly scored
or worn. To remove the wear plate, disengage the
hardware (11 and 12).
Inspect the back cover and wear plate O‐rings (10
and 13) and replace them if damaged or worn.
Suction Check Valve Removal
(Figure 1)
If the check valve assembly (34) is to be serviced,
remove the check valve pin (35), reach through the
back cover opening and pull the complete assem­
bly from the suction flange (30).
NOTE
Further disassembly of the check valve is not re­
quired since it must be replaced as a complete unit.
Individual parts are not sold separately.
Rotating Assembly Removal
(Figure 2)
The rotating assembly may be serviced without
disconnecting the suction or discharge piping;
however, the power source must be removed to
provide clearance.
The impeller (1) should be loosened while the rotat­
ing assembly is still secured to the pump casing.
Before loosening the impeller, remove the seal cav­
ity drain plug (20) and drain the seal lubricant. This
will prevent the oil in the seal cavity from escaping
when the impeller is loosened. Clean and reinstall
the seal cavity drain plug.
Immobilize the impeller by wedging a block wood
between the vanes and the pump casing, and re­
move the impeller capscrew and washer (27 and
28).
Install the shaft key (17). Install a lathe dog on the
drive end of the shaft (22) with the “V” notch posi­
tioned over the shaft keyway.
With the impeller rotation still blocked, see Figure 3
and use a long piece of heavy bar stock to pry
against the arm of the lathe dog in a counterclock­
wise direction (when facing the drive end of the
shaft). Use caution not to damage the shaft or key­
way. When the impeller breaks loose, remove the
lathe dog and wood block.
NOTE
Do not remove the impeller until the rotating assem­
bly has been removed from the pump casing.
Turn
Counterclockwise
Lathe Dog Arm
“V” Notch
Shaft Key
Impeller Shaft
Lathe Dog
Setscrew
Heavy
Bar Stock
Figure 3. Loosening Impeller
(Figure 1)
Remove the hardware (4 and 5) securing the rotat­
ing assembly to the pump casing. Separate the ro­
tating assembly by pulling straight away from the
pump casing. Tie and tag the rotating assembly
shims (6) for ease of reassembly.
NOTE
An optional disassembly tool is available from the
factory. If the tool is used, follow the instructions