Wanner International Hydra-Cell Pump G-25-I

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

Check the oil level in the upper oil reservoir

Is the oil condition acceptable?

Is the oil contaminated or discolored?

Remove contaminated oil if present

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.

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

Valve Plate and Manifold Installation

Install valve assemblies in valve plate (18)

Install valve plate (18) on cylinder housing (25) with three cap screws (39)

Reinstall O-rings (8, 9, and 10) between valve plate and manifold (7)

Reinstall manifold (7) onto valve plate (18)

Insert all bolts (5), washers (6), and nuts (31) around edge of manifold, and centerbolt (1) with washer (2). Hand tighten.

Torque Specifications for Model H-25

Alternately tighten opposite bolts (5) until all are secure