An improved life hydraulic valve actuator for a mold used in an injection molding machine. The actuator includes a housing for insertion into a hot runner assembly having a movable valve gate pin. A bore in the housing for receives an actuation piston which is connected to the gate pin. A hydraulic chamber in the assembly lifts the piston upward and downward for actuation of the pin in a valve gate. The actuation piston includes a centrally located circumferential double lip seal. The wall of the bore includes a pair of circumferential seals for engaging the outer circumference of the piston. The seals are positioned axially on either side of said centrally located double lip seal of the piston for sealing and guiding the piston. The circumferential bore seals include a Teflon ring which protects the bore in the event of seal failure and a second seal made of a Viton material. The seals in combination increase the longevity of the actuator over three fold than a similar actuation valve.