BELT 5391146 - Caterpillar

Malfunction Finding Procedures
A number of procedures to determine the correct cause of a certain malfunction are described below.Procedure to Check the Correct Operation Of the Grease Pressure Switch and Cable
Disconnect the two pole connector from the pressure switch.
Measure the resistance between the two contacts with a multimeter. When the system has no pressure, the contact of the switch should be open. If required, remove the switch in order to make sure that no grease pressure is present below the pressure switch. Remove only the upper part, the diverter valve can be left in place.Note: When the adjusted pressure (see the side of appropriate switch) is reached, the contact should close.
Start a test cycle by pressing the push button on the pump.
When possible, mount a pressure gauge between the diverter valve and the pressure switch in order to check the switch.Note: Use a pressure gauge that is suitable for a grease pressure up to 250 bar (3625 psi). Because the connector of the grease pressure switch is disconnected, the control unit cannot switch off the pump when the adjusted pressure is reached.
Turn off the contact switch when the pressure for the switch has been reached. The test cycle has ended.Note: If the pressure switch functions properly, the cable should be checked for breaks inside the cable.
Disconnect the connector for the pump.
Connect both contacts of the connector of the pressure switch with a separate wire.
Measure the resistance between pin 7 and pin 8 of the connector for the pump. There should be nearly zero resistance that is measured.
Remove the wire that is between the contacts of the connector of the pressure switch. The multimeter should read open load.Procedure to Check the working Of the Pump and the 5/2 Magnetic Valve
Disconnect both grease lines from the pump unit.Note: Grease pressure may still be present in the lines.
Connect a pressure gauge to each line of the pump unit. Use pressure gauges that are suitable to 250 bar (3625 psi).
Press the test push button for about 4 seconds in order to start a test cycle. The pump now pumps grease from one of the channels. The pressure reading of the gauge that is connected to this line should increase to the maximum attainable pressure of 230 bar (3335 psi) to 250 bar (3625 psi).Note: The pump is not switched off by the pressure switch, because the system is disconnected.If the pump does not reach the indicated pressure, check the following:
An air lock is in the grease. This air lock can be identified by air bubbles in the grease. Disconnect the pressure gauge and allow the grease to flow until no air bubbles come from the line. If necessary, refill the reservoir with oil in order to remove the air that is around the pump element.
The grease is viscous and cannot be sucked in by the pump piston. Replace the grease in the reservoir and the main lines.
The pump is faulty. Replace the pump.
End the test cycle by turning off the contact switch or