Blackmer Pump GNX(H)4A

Check if any O-rings have been removed or disturbed during disassembly

Replace disturbed or removed O-rings with new ones

Heat PTFE O-rings in hot water before installation

Mechanical Seal Inspection and Replacement

Is there excessive or continuous leakage from the tell-tale hole in the bearing cover?

Replace the entire mechanical seal if leakage is detected

Refer to 'General Pump Troubleshooting' for possible causes of seal leakage

Ensure maintenance is performed by qualified technicians only

Follow the appropriate procedures and warnings as presented in the manual

Flush the pump per instructions in the manual

Drain and relieve pressure from the pump and system as required

Remove the head assembly from the outboard (nondrive) side of the pump according to steps 5 - 8 in the 'Pump Disassembly' section of the manual

Remove the head capscrews (21) and gently pry the head away from the cylinder

Open the discharge valve and close the intake valve

Bleed air into the pump through the intake gauge plug hole or auxiliary fitting

Pump air for 30 second intervals

Run a system compatible flushing fluid through the pump for one minute

Repeat initial flushing procedure to remove the flushing fluid

Disconnect and lockout electrical power or engine drive before maintenance

Relieve system pressure before maintenance

Flush and decontaminate system if pumping hazardous or toxic fluids

Ensure pump is not running before lubrication

Check grease relief fittings (76A) for proper function

Remove the grease relief fittings (76A) from the bearing covers (27, 27A)

Relief Valve Setting and Adjustment

Ensure safety precautions are in place

Remove the relief valve cap and gasket

Loosen the locknut, if equipped

Turn the adjusting screw inward (clockwise)

Inspect the R/V cap gasket and replace if required

Reattach the R/V cap gasket and cap