IF YOU ENCOUNTER A VEHICLE THAT HAS A GROANING TYPE NOISE COMING FROM THE POWER STEERING PUMP WHEN THE WHEEL IS TURNED TO THE FULL RIGHT OR LEFT POSITION WHEN THE VEHICLE IS PARKED, IT MAY BE CAUSED BY THE RELIEF VALVE VIBRATING WITHIN THE PUMP. IN LIEU OF REPLACING THE POWER STEERING PUMP, THE RELIEF VALVE IS NOW AVAILABLE AS A REPLACEMENT PART.