when the car stands still , my power steering gets stiff , but when I'm riding it's Okey again . Why does that happen ?
My power steering oil is just a bit lower then where the max. stripe is.
When I want to reverse the car , it gets really hard to turn my steering wheel
Sounds like power steering pump or rack n pinion might be getting bad.
Try adding Lucas Power Steering Stop Leak this not only stops leaks but also corrects hard steering used it when a friend of mine had the same problem you are having solved problem as soon as it was put in. To remove some fluid from the power steering pump use something like a turkey baster.