When i start my tractor the oil pressure is around 50 PSI on gauge. It has new oil and i was told to use 10W30. The oil has been changed twice with in the last 6 months.Most of the time when i drive it the pressure stays around 30 PSI when its hot. The other day i drove it and my oil pressure when the tractor was hot on idle i had no oil pressure on the gauge. Only when i raised the RPM did the pressure go up. my question is do i need to rebuild the pump its just gears or d oi need to use heaver oil.