DISASSEMBLE
Pressure Sensor
1.
Remove cover and lift up clip (1a) to unplug the sensor.
Remove sensor housing
Upper Housing
2.
Loosen but do not remove the four pump head screws
and carefully remove the upper housing assembly (1b).
3.
Inspect the B/F valve in center behind sensor for debris.
4.
Change the four ferrules sealing the screws.
Check Valve Assembly
5.
Inspect the valve flappers for debris and resilience.
6.
Replace if necessary.
Lower Housing, Diaphragm, Motor
7.
Remove mounting feet to expose notches. Rotate the
lower housing (4) so notch opening exposes set screw
that holds bearing housing to motor shaft.
8.
Loosen the set screw with an 1/8" Allen wrench inserted
through the notch opening. Finally, slide lower housing (4)
off motor shaft.
Diaphragm Cont’d
9.
Remove four piston screws from cam bearing assembly
using a Phillips screw driver and pull apart cam bearing
assembly from inner pistons.
Motor Cont’d
10.
Test motor by very carefully connecting red wire to posi-
tive (+) and black wire to negative ground (-) of a 12 or
24Vdc battery. Motor will run full speed and slow as sen-
sor is brought closer to a magnet’s south pole. Replace if
necessary.
REASSEMBLE
Motor
1.
Assemble lower housing assembly (4) to motor. (Follow
steps 4 to 10.)
Diaphragm
2.
Diaphragm (3) and lower housing (4) are assembled in
this way:
• Four black inner piston facing stem up on a flat surface,
diaphragm flat side up with piston stems through
diaphragm.
2.
• White outer piston must be folded to insert into lower
housing, flat side up.
2.
• Hex stem of inner pistons must align with hex holes in
outer pistons.
2.
• Outer pistons must be aligned with alignment slots on
the cam bearing assembly.
2.
• Drive each Phillips head screw partially tight, carefully
center each piston in its quadrant, and then tighten the
screws securely (18 in. lbs. torque).
Lower Housing
3.
Attach lower housing to motor shaft by aligning indention
in shaft with set screw. Set screw must align with the
shaft indention or major damage, poor performance or
high amp draw may result.
Upper Housing, Check Valves
4.
View the inside of the upper housing (1) and seat the four
ferrules in the pump head screw recesses.
5.
Carefully seat the O-ring in the check valve assembly
(O-ring must not slip out of the check valve recess.)
6.
Install check valve assembly into upper housing, pressing
firmly. Start the four pump head screws, turning by hand
through the ferrule seals, then push through about 1
1
⁄
2
".
7.
Assembly on to lower housing (4), align four screws to
motor by rotating lower housing if necessary to align feet.
8.
Tighten pump head screws evenly to a watertight
30 in. lbs. torque.
Pressure Sensor
9.
Place sensor housing (1a) and sealing disk against upper
housing (1b), insert screws and take care not to cross
thread or strip out threads in upper housing.
10.
Slide the sensor under the clip on the sensor housing,
and install the cover.
2
1b
1a
4
8
3
5
VARIABLE SPEED WATER PUMP SERVICE PARTS
Key
Description
Model #4515-743
Model #4525-743
0
Service Kit*
20409-043
20409-043
1
Upper Housing with Sensor Housing
20404-027
20404-028
2
Check Valve Assembly
20407-030
20407-030
3
Diaphragm Assembly (includes screws)
20403-040
20403-040
4
Lower Housing Assembly
20419-002
20419-002
5
Motors with Sensor
R2009-128A
R2009-127A
7
Pump Head Assembly
20406-037A
20406-038A
8
Side Clips (pair)
20408-000
20408-000
*Service Kit includes #2, #3, #8 and drive cam assembly.
