Maintenance - Sears 390.250251 Owner's Manual

4. Lubricate inside diameter and outer face of rubber
drive ring with soapy water and slide assembly on
motor shaft (sealing face first) until rubber drive
ring hits shaft shoulder.
5. Screw impeller on shaft until impeller hub hits shaft
shoulder. This will automatically locate seal in place
and move the sealing washer face up against seat
facing.
Cleaning Impeller
1. Disconnect power.
2. Remove motor.
(a) Remove motor wiring from pressure switch.
(b) Remove 4 capscrews, Key No. 17, Page 10,
which hold the motor to the pump body.
(c) Remove motor, seal plate, impeller and diffuser,
(Key Nos. 1, 3, 6 and 7), Page 10, as a unit.
Diffuser, Key No. 7, can now be lifted off and the
impeller exposed and cleaned.
Replacing Venturi
Follow Steps 1 and 2 above, for Cleaning
Impeller.
1. Remove venturi, Key No. 9, Page 10, by turning it
counter-clockwise. This will expose the nozzle, Key
No. 10, which can be removed by using a 5/8" hex
socket and turning it counter-clockwise.
2. To replace venturi, turn it clockwise until snug.
3. Replace all parts. Connect motor wiring and turn
on power.
Cleaning Shallow Well Jet
Follow Steps 1 and 2 above, for Cleaning
Impeller.
1. Observe venturi, Key No. 9, Page 10, which is po-
sitioned in pump body, Key No. 13.
2. Nozzle, Key No. 10, is directly behind the venturi
in the pump body.
3. Insert an ice pick or other small diameter pointed
tool through the venturi and into the nozzle. This
will dislodge foreign material.
4. Foreign material will drop to the bottom of the
pump body (directly below the nozzle) and must be
removed.
5. Replace all parts. Connect motor wiring and turn
on power.
Pump Performance (In Gallons per Minute)
Pump
Model Description
1/2 HP Standard S.W. Jet
390.250251 Use 1-1/4" Plastic Pipe
80 PSI Minimum Rating

MAINTENANCE

HOW TO HANDLE
A GASEOUS WELL
In some localities well water contains gases which
must be allowed to escape before the water is used.
This can be done as shown in Figure 6.
A good way of delivering gas-free water is to suspend
a pipe, closed at the bottom and open at the top, sur-
rounding the suction pipe, Figure 6. Since the gases
rise in the well casing, the water sucked down through
the pipe and into the suction pipe is free of gas. It is
imperative that this type of well be vented to the out-
side of any enclosure.
Air Control In Flowing Wells
Flowing wells, or wells with little or no drawdown,
could create a special problem in air control in the op-
eration of your water system.
In such cases, it is recommended that you install a
SEARS Captive Air
anism is not required.
Figure 6
Suct. Disch. Pressure PSI
1-1/4" 3/4"
8
® Tank, in which an air control mech-
Gases
rise to
surface
Pipe strap or
wire to hold
pipe sleeve
Tail
pipe
Not
Foot
to
valve
Scale
Pipe
2369 0396
sleeve
Pipe
cap
Pumping Depth in Feet
Discharge
5'
40 7.3
10' 15' 20'
6.2 5.2 4.2