What exactly does the Pressure Relief valve or spring do ? my new rebuilt trans has Ck,s new pump set up by him and every billet part he sells and his shift plate, the trans was dual feed also. the problem I am having is the trans is holding 2nd gear for longer and right before it shifts into 3rd gear it makes a Buzzing noise or like pump whine noise the tv adjustment made very little difference the pump has good pressures over 250 at full tv and the cooler pressures are 38# any ideas ??