Sun Pumps AP-SDS User Manual

SDS-D SERIES PUMP REBUILD INSTRUCTIONS

1 ½”

DISASSEMBLY

1. Remove cable guard screws (Item 21).

2. Remove the 3/8" NC set screw (Item 19) using 3/16" hex wrench. WARNING: PUMP

HOUSING MAY BE UNDER HIGH PRESSURE. USE EXTREME CAUTION IN
REMOVING THE END CAP PLUG AND END CAP SCREWS. We recommend

loosening the discharge head bolts first and pull the discharge head up slightly to relieve
any pressure that may be inside.

3. Remove the two socket head screws (Item 2) from end cap assembly (Item 17) using a
5/32" hex wrench.

4. Clamp the pump in the puller and screw the threaded mandrel in the end cap.

5. Pull the end cap out of the stainless housing. As the end cap (Item 17) comes out
disconnect the two motor wires plugged into the cap.

6. With the end cap removed from the housing, place the push plate across the two motor
nuts with the center hole facing up. Reinstall the puller and place the end of the threaded
rod inside the hole of the push plate.

With a 9/16” wrench, turn the bottom nut counter-clockwise to push the pump assembly
out of the stainless steel housing.

7. Remove the four socket head screws (Item 2) from the discharge head using a 5/32"
hex wrench.

8. Remove the bypass valves and springs (Items 8 & 9), suction screen (Item 5), check
valve body (Item 7) and check valve O-ring (Item 6) from the discharge head. Note:

Check valve removal may require a light tap with a blunt tool through the discharge
opening.

9. Remove the two motor adapter screws (Items 10) using a 5/32" hex wrench. Remove
the set screw from the cam assembly using a long 1/8" hex wrench. This wrench must be
inserted through the slot in the side of the motor adapter (Item 14). Before inserting the
wrench, visually align the set screw with the hole by turning the motor adapter while
holding the motor.

10. Pull the motor adapter and cam assembly away from the motor, remove the two piston
screws (Item 23), and then the cam assembly (Item 15).

11. Discard outer pistons (Item 13), O-rings (Items 18), diaphragm (Item 12), check valve
(Item 7), and O-ring (Item 6).

12. Clean and inspect all remaining parts and make sure that the electrical studs
protruding from the epoxy in the end cap are in good condition and the epoxy is still hard.