Hydraulic tensioner with pressure relief valve

A hydraulic tensioner comprising:

• a housing having a generally cylindrical bore,
• a hollow piston having an upper end and a lower end, said piston being slidably received within said bore, said lower end of said piston being received in said bore to form a fluid chamber with said bore,
• a spring positioned within said piston, said spring biasing said piston in an outward axial direction from said bore,
• a check valve positioned in a fluid passage between said fluid chamber and a source of pressurized fluid to permit fluid flow into the fluid chamber while blocking flow in the reverse direction,
• a pressure relief valve positioned within said upper end of said piston, said pressure relief valve having a conduit in fluid communication with said fluid chamber to permit passage of fluid from said fluid chamber under specified pressure conditions, said pressure relief valve having a seat member and a valve member, said valve member being translatable within said seat member in said axial direction;
• a valve spring biasing said valve member against said valve seat member and in the axial direction toward said fluid chamber, said valve spring being positioned between said seat member and a retention member, said retention member being integral with a stem portion of said valve member, said valve member moving away from said seat member to permit fluid flow between said valve member and said seat member when said specified pressure conditions are attained in said fluid chamber, wherein said valve retention member abuts a bottom surface of said seat member to limit said valve stem portion outer movement in the axial direction.