Fault Phenomenon: Komatsu GD825 grader engine power is low, black smoke from exhaust.

Troubleshooting Process:
– Checked pre-cleaner: rotating vanes seized by mud.
– Checked intake resistance: extremely high intake resistance.
– Checked main filter: main filter clogged quickly.
– Checked environment: high mud content in operating environment.

Root Cause: The rotating vanes of the intake pre-cleaner were seized by wet mud, losing centrifugal separation capability, causing the main filter to clog rapidly and resulting in insufficient intake air.

Required Parts: Clean or replace intake pre-cleaner assembly.