My truck is experiencing some power steering problems its 4x4 3500. Some times the steering wheel is very hard to turn till I start to move in forward or reverse, it has 52000 miles on it and I have flushed the steering fluid but its not seem to help . Is there anything I can do?
Thanks in advance.

 

Could be the bypass valve in the pump is failing. Had this happen to my F250 a few years ago.