The molded rubber gasket seal was integrated into a hydraulic lift operating at 650 psi. Over time it had developed a very small hole and approximately 60 gallons of hydraulic oil escaped through this small leak. Read Consulting Failure Analysis Lab was asked to perform a detailed failure analysis to determine the cause of the leak. The subject rubber seal failed as a result of a rubber molding defect. During the molding operation , here was a region where the flowing rubber failed to re-bond properly. Over time the high pressure (650 psi) hydraulic oil created a hole in the weakened rubber and this resulted into a rubber failure and a hydraulic leak. Upper left is a 30X photo-micrograph of the pinhole leak. The leak “protrudes” outward showing that the failure was created as a result of the hydraulic pressure.