Defective solenoids disrupt the proper operation of Milk Meters. Before replacing a solenoid, perform the following inspections to verify the necessity of replacement or to identify potential alternative issues. To determine if solenoid replacement is required: Set the MPC control panel to Cleaning mode and press. Verify that the valve stem within the Milk Meter body rises and falls at 10-second intervals. Disconnect the vacuum line from the solenoid fitting and cover the tube end with your finger to check for vacuum suction. At the milking point connector, disconnect the solenoid wires (Red and Black) and test their resistance using a multimeter. Release the bottom clamp on the Milk Meter, remove the lower cover, and inspect the diaphragm for wear. If these inspections reveal no faults, remove the old solenoid and replace it with a new unit. Reassemble the Milk Meter, secure the lower cover, and connect the vacuum and exhaust lines to the corresponding solenoid fittings.