Maintenance
Manual
8
Ampco
Pumps
Company
9. Slide the impeller onto the pump shaft over the key. Next, lubricate the impeller nut gasket and install it on the impeller along
with threading on the impeller nut. Be sure that the gasket fits into the groove in the impeller nut. For SP 240 pumps lubricate and
install both impeller bolt and washer O-rings.
10. Tighten the impeller nut. This should be done with a 15/16” socket (7/8” for SP 240 pumps) while using a 3/8” rod in the stub
shaft hole to keep the pump shaft from rotating. Check the freedom of parts by hand rotating the impeller.
11. Install the cover onto the pump volute with a new cover O-ring. It is best to put the O-ring on the cover as it is placed against
the volute. Tighten all cover nuts uniformly. Rotate the shaft by hand again to check for rubbing.
12. Re-install the shaft cover guard.
13. For double seal pumps, install the flush lines through the back of the casing. Run flush water at about 1-2 gallons per hour.
The maximum pressure for the seal is 5 PSI. Flush water should be throttled before the pump, and there should be about 2-5 feet
of vertical tubing after the flush water exits the pump to maintain this.
14. Place the pump back into service and inspect for proper rotation and leaks.
Motor / Pump Shaft Disassembly
Before attempting any service on the pump and motor, disconnect or lock out electrical power to the pump motor. If the pump and
motor are to be removed as a unit, note the wiring configuration. Use colored or numbered tape to mark the wire connections of
the motor and power source, for reconnection.
1. Begin with pump disassembly as noted previously.
2. Loosen the shaft collar with an Allen wrench (see sizes in the table on page 10) so that the stub shaft can be taken off the
motor. A rubber mallet may be used to tap the stub shaft if it will not slide off. Be careful not to drop the shaft collar when the stub
shaft comes off the motor.
At this time the motor can be replaced by unbolting the adapter from it and separating the two items.
Motor / Pump Shaft Assembly
If the pump stub shaft is being replaced, it is recommended that a new shaft collar also be installed.
1. Begin by bolting the adapter onto the motor. Please note correct tightness of all fastening components in the table in page 10.
2. Slide the shaft collar onto the stub shaft and slide the two together onto the motor shaft, keeping the motor keyway in line with
one of the slots in the stub shaft. If the collar has an identification groove in it, this will rest against the step in the stub shaft.
3. Line up the slot in the collar with the stub shaft slot and motor keyway gap. Do not tighten the shaft collar yet. Since the shaft
was disassembled, the impeller clearance in the volute may have changed. The impeller must be positioned to ensure the impeller
will not rub and also for proper pump performance. The critical impeller gap is the gap between the volute and the impeller. This
will be measured using the spacer provided with the SP series pumps. Please see the table on page 10 within the manual for the
correct impeller gaps.
4. Slide the volute over the pump shaft and shoulder it against the adapter.
5. Use a 3/4" wrench to alternatively tighten all bolts between the volute and the adapter.
6. Place the spacer provided with the pump between the casing and the impeller. Install the impeller key, followed by the impel-
ler, impeller nut gasket, and impeller nut (bolt & washer, SP-240 only). Tighten the impeller nut using a socket wrench and the 3/8”
rod to hold the shaft to secure the assembly.
7. With a rubber mallet, gently tap the impeller nut (bolt & washer, SP-240 only) to drive the stub shaft towards the motor, while
the spacer is between the impeller and volute. This will create the critical impeller gap.
8. When the impeller gap is correct, align the shaft collar slot with the slot in the stub shaft and the motor shaft keyway, and
tighten the shaft collar with an Allen wrench, (see sizes in table on page 10) to secure the shaft position.
9. Remove the impeller nut (bolt & washer, SP-240 only), gasket, and impeller from the shaft, and the spacer. Now finish reas-
sembling the pump.
Ampco
Pumps
Company
SP
Series
Manual
M
‐
015
RevC
6.19
