Gorman-Rupp Pumps 81 1/2A3-B 275382 and up - Manual (Page 28)

OM−00743 80 SERIES
MAINTENANCE & REPAIR PAGE E − 9
Slide the shaft sleeve onto the impeller shaft until
the seal faces contact. Continue to push the sleeve
through the seal until the sleeve seats squarely
against the shaft shoulder.
Install the seal spring.
Impeller Installation
Inspect the impeller and replace it if cracked or
badly worn.
The shaft and impeller threads must be
completely clean before reinstalling the im-
peller. Even the slightest amount of dirt on
the threads can cause the impeller to seize
to the shaft, making future removal difficult
or impossible without damage to the im-
peller or shaft.
Install the same thickness of impeller shims (4) as
previously removed and screw the impeller onto
the shaft until tight.
Make sure the seal spring seats
squarely over the step on the back of the impeller.
The clearance between the back of the impeller
and the seal plate should be between 0.015 and
0.025 inch (0,38 to 0,63 mm). Measure this clear-
ance and add or remove shims from the impeller
adjusting shim set (4) until the correct clearance is
achieved.
Pump Casing and Wear Plate Installation
If the wear plate assembly (20) was removed,
install the new wear plate in the pump casing and
secure it with the hardware (22, 23, 34 and 35). Be
sure to install new fiber washer (23) and do not
over-tighten the capscrew (22). Over-tightening
the capscrew can crush the fiber washer, resulting
in leakage.
Remove the two capscrews temporarily securing
the seal plate to the pedestal. Install a new set of
casing gaskets (19) and slide the pump casing
over the impeller and against the gaskets. The
clearance between the face of the impeller and the
wear plate should be between .008 and .015 inch
(0,20 to 0,38 mm). Remove gaskets from the gas-
ket set until the correct clearance is achieved. Se-
cure the pump casing to the seal plate and pedes-
tal with the nuts (18).
Suction Check Valve Installation
If the check valve assembly (26) was disas-
sembled, use the hardware (28 and 29) to secure
the weights (27 and 30) to the new gasket (31).
Position the check valve assembly over the studs
with the large weight toward the inside of the
pump. Secure the suction flange (32) and check
valve assembly to the pump casing with the nuts
(25).
Check the operation of the check valve to ensure
proper seating and free movement.
Final Pump Reassembly
Be sure all hardware and drain plugs are tight, and
that the pump is secure to the base and power
source.
Install the suction and discharge lines and open all
valves. Make certain that all piping connections are
tight, and that the weight of the lines is indepen-
dently supported and secure.
Before starting the pump, fill the pump casing with
clean liquid. Apply Never-Seez" or equivalent
compound to the fill plug (33). Reinstall and tighten
the fill plug.
Refer to OPERATION, Section C, before putting
the pump back into service.
LUBRICATION
Seal Assembly
The shaft seal is lubricated by the liquid being
pumped and no additional lubrication is required.
Bearings
The pedestal was fully lubricated when shipped
from the factory. Under normal conditions, remove
the vented plug (10) and add three shots of No. 0
lithium base grease from a grease gun after each
250 hours of operation or once each month, which-