Fault Phenomenon: Caterpillar 336 excavator travel motor oil seal leaks frequently.

Troubleshooting Process:
– Checked drain line: motor drain line kinked or clogged.
– Checked internal pressure: motor housing pressure too high.
– Checked oil seal: oil seal damaged by high pressure.
– Checked oil level: tank oil level too high.

Root Cause: The travel motor drain line is clogged, preventing internal leakage oil from returning to the tank, causing high housing pressure that blows out the oil seal.

Required Parts: Clear or replace drain line, replace oil seal.