The replacement seal is installed, the cylinder is back in service, and then the leak returns. It’s tempting to blame the new seal, but the seal may be showing the effects of another problem. If the condition that damaged the first seal is still present, replacing it again may lead to the same result.
Here’s what to check before fitting another one.
When did the leak return?
The timing can help guide your inspection. If leakage starts immediately after installation, look for cuts or nicks from handling, tools or sharp edges. Check that the seal is positioned correctly.
If the leak develops after the cylinder has been operating, examine the failed seal for wear or material changes. Heat, pressure, fluid compatibility, contamination or side loading may be contributing factors. Timing and appearance offer clues, but neither confirms the root cause by itself.
What does the failed seal look like?
Nuraseal’s seal-failure guide describes common damage patterns and their possible causes. Use the pattern to focus your inspection:
- Uneven or one-sided wear may point to misalignment, a worn bearing or wear ring, or excess side load.
- A soft or swollen seal may indicate fluid absorption or an incompatible material and fluid combination.
- Hardening, glazing or cracks can be associated with excessive heat, fluid deterioration or material compatibility problems.
- Cuts, scratches or scoring may result from installation damage, burrs on contacting surfaces or contamination in the fluid.
- Extruded or ragged material may indicate excessive pressure, a gap between mating surfaces, worn bearings or an incorrectly sized backup ring.
Different causes can produce similar damage. Treat these patterns as starting points, then check the cylinder and operating conditions before deciding what to change.
Check the cylinder and its operating conditions
Inspect the rod and bore for scoring, burrs, wear or other damage. Check that the cylinder components are properly aligned and that bearings or wear rings are not worn. A damaged surface or guiding problem can continue to affect a replacement seal.
Then review how the system is operating. Note the fluid type, temperature and pressure, and whether any of these have changed. Consider whether contamination, pressure spikes or unexpected heat could be contributing to the failure.
Confirm the replacement is right for the application
Before restarting the cylinder, confirm that the replacement matches the required dimensions and profile. Check its orientation and installation, and make sure the material is suitable for the fluid and operating temperature.
Keep a record of the failed seal’s appearance, when the leak returned and the operating conditions at the time. These details can help distinguish a selection or installation issue from a problem elsewhere in the system.
Need help with a repeat seal failure?
Share your application details and photos of the failed seal with the Nuraseal Team to discuss your sealing requirements.