Cover seals with latching locking features

Seal apparatus comprising:

• a cover seal having a body and an extending cylindrical sleeve, the sleeve having a radial internal groove;
• a piston having a circumferential groove therein;
• a biasing element disposed within the internal and circumferential grooves, said biasing element comprising an elliptical coil spring, the internal groove includes a generally right angle shoulder, the circumferential groove includes an opposing angled shoulder and said elliptical spring is oriented by the right angle shoulder and angled shoulder with a point of contact between said elliptical spring and said angled shoulder spaced apart from an endpoint of a major axis of the spring to provide latching or locking between the seal and said piston;
• and
• surfaces disposed in said internal and circumferential grooves and orienting said biasing element in order to effect sealing between a housing and the sleeve and an axial force to provide latching or locking between the seal and said piston.