Wanner Engineering Pump H-25-X

Inlet and Outlet Valve Inspection

Replace worn spring retainer (16)

Replace valve spring (14) if shorter than new

Replace excessively worn valve poppet (13)

Inspect and replace valve seat (12) if necessary

Install new O-ring (11) on valve seat (12)

Clean valve ports and shoulders with emery cloth

Lift the diaphragm by one edge and turn the pump shaft until the diaphragm pulls up.

Insert an Allen wrench through one of the holes to hold the diaphragm up.

Diaphragm Removal and Inspection

Remove the screw (19), O-ring (20), and follower (21) in the center of the diaphragm.

Remove the diaphragm and inspect it carefully for damage.

Inspect the diaphragm for the following issues

Inspect the plunger (23) for any rough surfaces or edges.

Ensure the pump is turned off and cooled down

Gather necessary tools and materials for oil change

Remove the drain plug cap (34) at the bottom of the pump

Ensure all oil and accumulated sediment have drained out

Verify oil viscosity is between 16-20 cST (80-100 SSU)

Ensure the pump is turned off and cooled down

Gather necessary tools and materials for oil change

Remove the drain plug cap (34) at the bottom of the pump

Ensure all oil and accumulated sediment have drained out

Is the oil viscosity between 16-20 cST (80-100 SSU)?

Measure the oil level in the upper oil reservoir

Is the oil clean and uncontaminated?

Remove contaminated oil if discovered

Is there any oil loss without external leakage?