Oil Pressure Gauges are used in automotive and motorcycle industries. These consist of custom machined steel fitting to replace the operating valve plug, custom fabricated steel fitting to connect to the test port near the solenoid and custom fabricated steel fitting to replace the relief valve plug. It has high-pressure 3000-psi hose and brass connecting fittings. It allows the overdrive oil pump to operate while indicating oil pressure since the custom machined steel fitting duplicates the standard operating valve plug.