Pump Fault — Mechanical Seal Leak

What This Fault Means

A mechanical seal leak indicates fluid is escaping past the rotating seal faces. Minor weepage is normal, but visible dripping or streaming indicates seal failure that will worsen and can lead to bearing contamination.

Common Causes

• Seal face wear from normal service life
• Dry running (pump ran without fluid, destroying the seal faces)
• Abrasive particles in the fluid scoring the seal faces
• Shaft misalignment or excessive vibration cracking the seal
• Thermal shock from sudden temperature changes

Recommended Fix

1. Confirm the leak location — mechanical seal or gasket?
2. If the seal is weeping steadily, plan a seal replacement during the next scheduled downtime.
3. If the seal is streaming, shut down the pump to prevent bearing contamination.
4. When replacing, inspect the shaft sleeve for scoring — replace if grooved.
5. Ensure the seal flush line is flowing (if equipped) to keep the seal faces cool and clean.