Disassembly And Assembly Of Pump; Removing Motor For Service And Replacing Shaft Seal - Craftsman 390.2521 Owner's Manual

MAINTENANCE
DISASSEMBLY AND
ASSEMBLY OF PUMP
AWARNING] Risk
of electric shock. Ground unit and
disconnect power before attempting any work on
pump or motor.
Your Sears pmlap is designed for ease in servicing. Should
repair or replacement of the motor or seal be needed, the
pump and piping do not need to be disconnected or dis-
turbed.
1. Disassemble pump as follows:
A. Disconnect power.
B. Drain pump by opening drain cock. Remove pressure
switch tubing from fitting on top of pump.
[A WARNING ]To
avoid serious injury, release aH
pressure from system before attempting to remove
clamp from pump.
C. Remove clamp, Key No. 10, Page 12.
D. Remove pump base mounting bolts. Motor assembly
and back half assembly of pump can be pulled away
from front half.
E. Remove "O" rings.
2. Reassembly of pump.
A. Clean "O" rings and "O" ring grooves.
B. Lubricate "O" rings with petroleum jelly, and place in
grooves.
C. Slide pump halves together.
D. Clean inside of clamp. Place clamp around pump
halves. Alternately tighten clamp screw and tap clamp
around outside with plastic mallet. This will insure
proper seating of "O" ring and clamp.
E. Assemble base mounting bolts. Connect pressure
switch tubing and close drain cock.
F. Prime pump and tttm on power.
G. Check for leaks.
Removing Motor for Service
and Replacing Shaft Seal
If it is necessary to separate motor and seal plate, always re-
place the shaft seal. We suggest you purchase this item,
U109-6A, and have it on hand for future use.
NOTICE: The seal consists of two parts, a rotating member
and a ceramic seat. The surfaces of the seal are easily dam-
aged. Read instructions carefully.
1. Disassemble pump per instructions above.
2. Remove diffuser and impeller as follows (Key Nos. 8 and
9, Page 12).
A. Remove screws holding diffuser.
B. Loosen two screws and remove motor canopy from
motor.
C. Place 7/16" open end wrench on motor shaft flat.
D. Turn impeller counterclockwise when facing it.
3. Remove pump back half from motor by unscrewing four
(4) nuts. Pry back half off motor by inserting two (2)
screwdrivers between the back purnp half and the motor
flange. This will force rotating portion of seal off shaft.
See Figure 7.
)
475 0194
Figure 7
4. Place back haft of pump on flat surface and tap out ce-
ramic seat. See Figure 8.
479 0_94
Figure 8
5. Clean seal cavity.
6. Install new seal.
A. Clean polished surface of ceramic seat with clean
cloth.
9