Wanner International Hydra-Cell Pump G-25-X

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 center of diaphragm

Inspect diaphragm for damage or wear

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

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

Record the oil viscosity in cST

Is the oil viscosity within the acceptable range?

Check spring retainer (16) and replace if worn

Is the valve spring (14) shorter than a new spring?

Check valve poppet (13) and replace if worn

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

Clean valve ports and valve shoulders with emery cloth

Grease valve ports and valve shoulders with lubricating gel or petroleum jelly

Flush Contaminant from Hydraulic End

Remove oil drain cap (34) and allow all oil and contaminants to drain out. Replace oil drain cap.

Remove oil cap (28) and fill reservoir with kerosene or solvent, manually turn pump shaft to circulate kerosene, and drain.

Is the diaphragm made of EPDM or is food grade oil used in the reservoir?

If EPDM diaphragms or food grade oil is used, flush with the same lubricant used in the reservoir instead of kerosene or solvents.

Repeat the kerosene or solvent flush.

Fill reservoir with fresh oil, manually turn pump shaft to circulate oil, and drain once again.

Refill reservoir. If oil appears milky, repeat flushing procedure until oil appears clean.

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.