Abstract: A plastic molded part having a parting line free O-ring groove formed on a tubular portion of the part is made by molding the groove utilizing cooperating inner and outer axially moveable die portions in which an inner die member is withdrawn from the tubular plastic just before the outer die member is withdrawn, with the withdrawal of the members occurring after the plastic has begun to set but before it has assumed its final cure, whereby the plastic may flex inwardly as the outer die is withdrawn and then may spring back outwardly to its proper position for final cure.

Abstract: An all plastic cap for an automotive power steering reservoir includes a cap portion and a central integrally molded stem portion, the latter having oppositely extending integrally molded stiffly resilient locking ears with an elastomeric gasket disposed within the cap such that the ears may engage a cam lip within the reservoir neck as the cap is turned with the ears drawing the cap into the neck and squeezing the gasket to effect the seal of the neck opening.

Abstract: A one-way air valve for relieving pressure within the passenger compartment of an automobile includes a plastic frame having an air passage therethrough with a flap integrally molded with the frame but of more elastic material and connected to the frame by a living hinge. The flap is molded in a position extending through the passageway and the living hinge is spring loaded by swinging the flap back through the passageway to overlie the outside of the frame over the passageway, thereby biasing the flap against the frame.