Wanner International Hydra-Cell Pump H-25-S

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

Check spring retainer (16) and replace if worn

Check valve spring (14) and replace if shorter than new spring

Check valve poppet (13) and replace if worn

Inspect valve seat (12) for wear and replace if worn

Install new O-ring (11) if valve seat (12) is replaced

Clean valve ports and valve shoulders with emery cloth

Disassemble Pump Housing and Cylinder Housing

Remove pump head and diaphragms as outlined in Fluid-End Service Section.

Remove cap and drain oil from pump housing.

Set hydraulic end of pump face-down on cylinder housing.

Check cam assembly shaft for sharp burrs and smooth any burrs.

Remove four socket head screws and washers that secure cylinder housing to pump housing.

Inspect cam assembly and bearings. Contact Wanner Engineering if bearings are pitted or binding.

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

Insert Allen wrench through one of the machined cross holes to hold diaphragm up

Remove components from diaphragm center

Inspect plunger for rough surfaces or edges

Install new diaphragm or reinstall old diaphragm if in good condition, ridge side out

Clean screw and apply medium-strength threadlocker

Prime Hydraulic Cells on Standard Pumps

Remove oil cap and fill reservoir with correct Hydra-oil

Use catch basin for oil leaks and dispose of properly

Force air out of oil in hydraulic cell by turning shaft and pumping piston

Wipe excess oil from cylinder housing and diaphragms

Ensure oil is one inch (25 mm) from top of fill port

Prime Hydraulic Cells on Kel-Cell Pumps

Method #1 (with system head pressure less than 2 psi)