A bearing lubrication (oil circulation) system having a check valve configuration for preventing overflow of an oil reservoir or tank. The pressurized oil circulation system may comprise a pump that pressurizes oil from the tank and circulates the oil through a supply conduit to a bearing, and returns the oil to the tank through a return conduit. The system may include a check valve disposed in the supply conduit and a pilot-operated check valve disposed in the return conduit. The pilot may be taken from the supply conduit upstream of the check valve disposed on the supply conduit. When pressure is discharged from the oil circulation, such as with shutdown of a circulation pump, the check valves automatically close and thus prevent oil contained in the supply and return conduits from draining (i.e., by gravity) to the oil tank. Therefore, flooding of the oil tank with excessive oil is prevented. Furthermore, loss of oil from the bearing sump is also prevented.