Gorman-Rupp Pumps PAH4C60C-B 1503565 and up - Manual (Page 34)

OM-06479 PAH SERIES
MAINTENANCE & REPAIR PAGE E - 13
drain time, remove the air vented (12). Clean and
reinstall the drain plug and vent plug. Inspect the
oil for water, dirt or a cloudy condition which could
indicate seal failure.
Impeller Removal
(Figure 3)
With the pump casing removed, use an impact
wrench with a hex key to loosen the impeller caps­
crew (1). Remove the capscrew, impeller washer
(2) and roll pin (3).
Use a suitable three‐jawed puller to remove the im­
peller (4) and key (26) from the shaft (25). Use cau­
tion when removing the impeller; tension on the
shaft seal spring will be released as the impeller is
removed.
NOTE
An alternate method of removing the impeller is to
insert a pair of wedges 180
_ apart between the im­
peller and seal plate (10). Tap the wedges evenly in
an alternating pattern to “walk” the impeller off the
shaft.
Remove the impeller adjusting shims (5); tie and
tag the shims, or measure and record their thick­
ness for ease of reassembly.
Inspect the impeller and replace if cracked or badly
worn.
Seal Removal
(Figures 3 and 8)
Remove the spring centering washer and seal
spring. Slide the shaft sleeve (7) and rotating por­
tion of the seal off the shaft as a unit.
Apply oil to the shaft sleeve and work it up under
the rubber bellows. Slide the rotating portion of the
seal off the shaft sleeve. Remove the shaft sleeve
O‐ring (8).
Use a pair of stiff wires with hooked ends to remove
the stationary element from the seal plate bore.
An alternate method of removing the stationary
seal components is to remove the hardware (16
and 17) and separate the seal plate and gasket
(14) from the pedestal (18). Position the seal plate
on a flat surface with the impeller side down. Use a
wooden dowel or other suitable tool to press on the
back side of the stationary element until the ele­
ment and its O‐ring can be removed.
If no further disassembly is required, refer to Seal
Installation.
Separating Rotating Assembly From Power
Source
(Figure 1)
Further disassembly requires separating the rotat­
ing assembly from the power source. Remove the
coupling securing the rotating assembly to the
power source. Remove the belt (10).
Remove any hardware securing the pedestal (18,
Figure 3) to the base. Use a suitable hoist and sling
to move the rotating assembly to a clean, well‐
equipped workshop for further disassembly.
Remove the capscrews from the center of the
bushing (7). Reinstall the capscrews in the tapped
holes in the bushing and tighten them in an alter­
nating pattern until the bushing is “jacked” out of
the sheave (6). Slide the bushing and sheave off
the shaft. Remove the key (28, Figure 3).
Shaft and Bearing Removal and Disassembly
(Figure 3)
When the pump is properly operated and main­
tained, the pedestal (18) should not require disas­
sembly. Disassemble the shaft and bearings only
when there is evidence of wear or damage.
Shaft and bearing disassembly in the field
is not recommended. These operations
should be performed only in a properly
equipped shop by qualified personnel.
Remove the pedestal drain plug (15A) and drain
the lubricant. Clean and reinstall the drain plug. For
shorter drain time, remove the air vent (12A). Clean
and reinstall the drain plug and air vent after drain­
ing.