I have been working on a 04 Hyundai Elantra 2.0L and i am having a persistent issue with the power steering. When the car is running(driving) the car steers and the wheel turns easily. Only when the car is not in motion does it become difficult to turn the wheel. I have changed the power steering pump. I checked the hoses and no damage that I can see. The fluid is new. I checked the rack and pinion for leaks which it had none. I am truly at a loss and would greatly appreciate any help.