Gorman-Rupp Pumps 12C2-B 722995 and up - Manual (Page 28)

OM-00602 10 SERIES
MAINTENANCE & REPAIR PAGE E - 5
If the check valve assembly (5) is to be serviced, re­
move the check valve pin (4), reach through the
back cover opening and pull the complete assem­
bly from the suction flange (57).
Inspect the check valve parts for wear or damage.
If replacement is required, remove the nylock nuts
(10) and separate the check valve (8) from the
adaptor (6) and backup plate (9). Press the spacer
sleeves (7) out of the check valve.
If no further disassembly is required, see Suction
Check Valve Installation.
Pump Casing Removal
To service the impeller (2) or seal assembly (3), dis­
connect the discharge piping. Remove the hard­
ware securing the pump casing (1) to the base.
Remove the nuts (38) securing the pump casing
and gasket set (40) to the pedestal (31) and seal
plate (39). Separate the casing from the seal plate
and pedestal. Tie and tag any leveling shims used
under the pump mounting feet to ease reassembly.
Remove the gasket set (40) from the pedestal and
seal plate. Tie and tag the gaskets, or measure
and record their thickness for ease of reassembly.
Clean the mating surfaces of the seal plate and
pump casing.
Impeller Removal
Before removing the impeller, turn the cross arm on
the automatic grease cup (18) clockwise until it rest
against the cover (see Figure E-4). This will pre­
vent the grease from escaping when the impeller is
removed.
Disconnect the power source.
Immobilize the impeller by wedging a block wood
between the vanes. If removed, install the shaft
key (26). Install a lathe dog on the drive end of the
shaft (28) 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 E-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 E-2. Loosening Impeller
Unscrew the impeller from the shaft. Use caution
when removing the impeller; tension on the seal
spring will be released as the impeller is un­
screwed.
Inspect the impeller and replace it if cracked or
badly worn. Slide the impeller adjusting shims (15)
off the impeller shaft. Tie and tag the shims, or
measure and record their thickness for ease of
reassembly.
Seal Removal and Disassembly
(Figures E-1 and E-3)
Remove the grease cup and piping (16, 17 and 18)
from the seal plate. Slide the seal plate and seal as­
sembly off the shaft as a unit. Carefully remove the
rotating and stationary seal elements, packing
rings, stationary washers, seal spring and shaft
sleeve from the seal plate.
Inspect the seal liner (59) for wear or grooves
which could cause leakage or damage to the seal
packing rings. The seal liner is a press fit in the seal
plate and does not normally require replacement.
If seal liner replacement is required, refer to Seal
Reassembly and Installation.
If no further disassembly is required, see Seal
Reassembly and Installation.