Wanner International Hydra-Cell Pump H-25-I

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

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.

Inspect parts of the valve assemblies

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 necessary

Clean valve ports and valve shoulders with emery cloth

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

Check the inlet pressure or vacuum with a gauge

Is the vacuum at the pump inlet exceeding 7 in. Hg (180 mm Hg)?

Check the inlet piping system for blockages if vacuum exceeds 7 in. Hg

Check the fluid supply level if the pump inlet is above the supply tank

Replenish fluid supply if too low

Refer to the 'Shutdown Procedure' for freezing protection

Shutdown Procedure During Freezing Temperatures

Adjust the discharge pressure regulating valve to minimum pressure and stop the pump

Ensure you have the necessary tools: 3/8-in (10-mm) hex Allen wrench and 3/16-in (5-mm) hex Allen wrench.

Verify that the pump drive shaft is not turned during the procedure.

Manifold and Valve Plate Removal

Remove bolts and lockwashers around manifold

Ensure four bolts (26) through back of pump housing are not removed.

Remove centerbolt (1) and washer (2) in center of manifold using 3/8-in (10-mm) hex Allen wrench.

Remove manifold (7) and support plate (43, used on non-metallic pump only).

Inspect manifold for warping or wear around inlet and outlet ports.