A grease tool lubricates a valve having an actuator assembly for moving a valve element of the valve. The tool has a housing with a piston carried in a bore. The housing is open for inserting and sealing a portion of the actuator assembly into the bore. A fill port in the housing allows grease to be introduced into the bore. A piston rod joins the piston and has external threads engaging internal threads of the housing, so that rotating the piston rod causes the piston to move axially. A lever is mounted to the housing for imparting rotation to the housing. A lock pin extends through a side wall of the housing to engage the actuator assembly to cause the actuator assembly to rotate in unison with the housing.