Apparatus and method for a hydraulic valvetrain system

An apparatus for a hydraulic valvetrain system, the apparatus comprising:

• a first oil retaining means;
• a second oil retaining means;
• and
• an oil conveyance means having a first end operably connected to the first oil retaining means and a second end operably connected to the second oil retaining means;
• wherein
• the second oil retaining means is configured to receive oil from the first oil retaining means via the oil conveyance means during operation of the hydraulic valvetrain system;
• the first oil retaining means is configured to receive oil from the oil conveyance means following cessation of operation of the hydraulic valvetrain system;
• and
• upon contraction of an oil volume during a reduction of oil temperature, oil from the second oil retaining means passes into the oil conveyance means to prevent air entering the hydraulic valvetrain system;
• the first oil retaining means comprises an oil flow aperture through which oil can pass;
• and
• the second oil retaining means is arranged to provide a pressure balance to prevent oil leakage through the oil flow aperture.