Fault Phenomenon: XCMG GR1803 grader after a new filter is installed, the instrument still indicates a filter blockage.

Troubleshooting Process:
– Checked filter: new filter intact.
– Checked sensor: pressure differential sensor zero-point drift.
– Checked wiring: poor contact.
– Checked reset: alarm not manually reset.

Root Cause: The filter blockage alarm sensor is faulty or the system was not reset after the filter was changed.

Required Parts: Replace pressure differential sensor or perform reset procedure.