Abstract: A method for assembling components that are sealed hydraulically or pneumatically includes forming an outer component having an inner surface, a groove for holding a seal, the groove having an opening at the inner surface. A seal is fabricated in the form of a substantially circular ring having a scarf cut extending through the width and the thickness of the seal, and a second inner surface having an inside diameter. The seal is then placing over a mandrel having a diameter that is larger than the inside diameter of the second inner surface so that the seal is expanded by plastic deformation such that a gap is formed at the scarf cut. Then the seal is inserted in the groove while the seal is expanded.