Leakage and Troubleshooting

• Technical Article - Three Attributes of Failed Seals and Their Common Causes

The Oil Seal Manufacturing Industry is committed to providing functional, efficient radial lip seals for all applications. If a sealing system leaks, it is most important that the manufacturer is provided with as much data about the sealing system and its environment as possible in order to provide a timely and correct solution. The mere return of a leaking seal is not sufficient information on which to base corrective action. The following is a Leakage Analysis Guide prepared by the Technical Committee of the Oil Seal Subdivision of the Rubber Manufacturers Association**.

There are four elements to any sealing system. They are:

1. The sealing device
2. The shaft or running surface
3. The housing bore
4. The medium to be sealed

It is not possible to provide an accurate analysis of a leaking sealing system without examination of all four elements.

The purpose of this document is:

• To provide the seal user with a systematic method of documenting all factors related to a sealing system and its immediate environment.
• To provide a comprehensive list of probable causes for the factors of conditions found.
• To provide possible corrective actions for conditions found. This may enable the user to solve the problem without consulting the seal manufacturer.
• To provide the seal manufacturer with comprehensive documentation of a sealing system deficiency.

This document contains a three-part checklist designed to lead an investigator through a sequential sealing system leakage analysis:

• Part 1: Examination of the sealing system and immediate environment with the seal in place
• Part 2: Examination of the seal after removal
• Part 3: Examination of the other three elements (i.e., housing, shaft and lubricant) of the sealing system
• Short Form (Note: A one page Short Form of the checklist, intended for field or shop use where the more comprehensive three part checklist may not be practical, is also included)

Completion of this three-part checklist should provide the examiner and eventually the seal manufacturer with sufficient information to diagnose the problem.

For each abnormal condition of the checklist, there is a reference code. Each reference code represents a page in the Causes and Countermeasures section of this guide. If a condition is checked on the list, the guide will provide a number of possible causes for that condition, as well as a number of possible countermeasures or corrective actions that could be taken by the responsible agency.

If the problem is not correctable by the user, the checklist should be forwarded, with the seal in question, to the seal manufacturer. If it is not possible to provide all of the information requested on the checklist, it would be of benefit to the seal manufacturer to have access to all elements of the sealing system so that all relevant information can be gathered.

See a list of problems, probable causes and actions or countermeasures