Fault Phenomenon: Caterpillar 336 excavator bucket cylinder leaks oil, and the piston rod surface is rough.

Troubleshooting Process:
– Checked piston rod: large areas of hard chrome plating peeled off.
– Checked oil seal: seal lip scratched.
– Checked environment: corrosive environment or impact from debris.
– Checked lubrication: lack of protection.

Root Cause: The hard chrome plating on the bucket cylinder piston rod peeled off due to corrosion or external impact, damaging the seal and causing leakage.

Required Parts: Re-chrome piston rod or replace cylinder assembly.