Gorman-Rupp Pumps 11 1/2A20-B 519865 and up - Manual (Page 28)

OM-00573 10 SERIES
MAINTENANCE & REPAIR PAGE E - 5
Pump Casing Removal
Death or serious personal injury and
damage to the pump or components
can occur if proper lifting procedures
are not observed. Make certain that
hoists, chains, slings or cables are in
good working condition and of suffi­
cient capacity and that they are posi­
tioned so that loads will be balanced
and the pump or components will not be
damaged when lifting. Suction and dis­
charge hoses and piping must be re­
moved from the pump before lifting. Lift
the pump or component only as high as
necessary and keep personnel away
from suspended objects.
To service the impeller or seal assembly, discon­
nect the discharge piping. Remove the hardware
securing the pump to the base. Disconnect the
power source. Tie and tag any leveling shims used
under the pump mounting feet to ease reassembly.
Remove the nuts (35) and separate the pump cas­
ing and gasket set (37) from the seal plate (36) and
pedestal (19). Clean the mating surfaces of the
seal plate and pump casing. Tie and tag the gas­
kets, or measure and record their thickness for
ease of reassembly.
Impeller Removal
Before removing the impeller, remove the bottle oil­
er and piping (10, 11, 12 and 13). Remove the seal
cavity drain plug (32) and drain the oil from the seal
cavity to prevent the oil from escaping when the im­
peller is removed. Clean and reinstall the drain
plug.
Immobilize the impeller (2) by wedging a block of
wood between the vanes. If removed, install the
shaft key (26). Install a lathe dog on the drive end of
the shaft (27) with the “V” notch positioned over the
shaft keyway.
With the impeller rotation still blocked, strike the
lathe dog sharply in a counterclockwise direction
(when facing the drive end of the shaft). The impel­
ler may also be loosened by using a long piece of
heavy bar stock to pry against the arm of the lathe
dog in a counterclockwise direction (when facing
the drive end of the shaft) as shown in Figure 2.
Use caution not to damage the shaft or keyway.
When the impeller breaks loose, remove the lathe
dog and wood block and unscrew the impeller
from the shaft.
Turn
Counterclockwise
Lathe Dog Arm
“V” Notch
Shaft Key
Impeller Shaft
Lathe Dog
Setscrew
Heavy
Bar Stock
Figure 2. Loosening Impeller
Unscrew the impeller in a counterclockwise direc­
tion. Use caution when removing the impeller; ten­
sion on the seal spring will be released as the im­
peller is unscrewed.
Inspect the impeller and replace it if cracked or
badly worn. Slide the impeller adjusting shims (57)
off the impeller shaft. Tie and tag the shims or mea­
sure and record their thickness for ease of reas­
sembly.
Seal Removal and Disassembly
Remove the spring centering washer (56) and the
seal spring. Slide the shaft sleeve (33) and rotating
portion of the seal off the shaft as a single unit. Ap­
ply oil to the sleeve and work it up under the bel­
lows. Slide the rotating portion of the seal off the
shaft.
Slide the seal plate and seal assembly off the shaft
as a single unit. Place the seal plate on a flat sur­
face with the impeller side down. Use a suitably
sized dowel to press the seal components from the
seal plate.