Sealing System Leakage Analysis - Case and O.D.




Measure Seal Outer Diameter

Probable Causes Actions or Countermeasures
Wrong seal for the application. Check for proper seal identification.
Bore or housing reworked. Check housing print. Also check for evidence of rework such as chuck marks.




Check for Severe Scratches on the OD

Probable Causes Actions or Countermeasures
Damaged bore or bore chamfer. Check condition of bore and chamfer.
Die scratches from case forming operation Check for OD coating or sealant in scratches.

Below is an example of a seal that was installed with no lead in chamfer on the bore.




Check for Peeled Rubber on the OD

Probable Causes Actions or Countermeasures
Poor rubber bond to case. Case OD clean at rubber interface.
Lack of lubrication of OD at assembly. Case OD has rubber adhering to it.
Lack of proper lead-in chamfer. Check bore chamfer condition



Check for hardness on the Rubber OD

Probable Causes Actions or Countermeasures
Excessive heat in application. Check for other evidence of overheating.
Improper seal material selection. Check material vs. operating temperature or lube compatibility.



Rubber OD Nonfills and Cuts

Probable Causes Actions or Countermeasures
Improper seal manufacture. Prep weight or shape out of spec. Consult seal manufacturer.
Bore chamfer sharp or damaged. Inspect bore chamfer.


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February 23rd
Here is a great article on grease compatibility . . .
The Skinny on Grease Compatibility

July 30th
 Here is a link to a great article about how to avoid particulate contamination . . . Obviously it goes without saying that a sealing...
How to Avoid Particulate Contamination