Power steering issues - noisy on tickover only

[joeyk07]

I've searched through the forum for some answers but I thought I might ask the community for their thoughts.

So I'm getting some vibration coming through the steering wheel when turning in a stationary position. Yes it moans even more on full lock.
I've checked the fluid and there's no loss, no leaks from what I can tell either.

If I give it a few revs and try to turn the wheel there's no noise or vibration, would that suggest the pump is ok? I've read in a few posts about a return valve which might be faulty, can someone elaborate this for me.

I'm about to hit the button on ordering a new pump but I'm hesitant to waste my money.

Any advice or experience of this problem would be helpful. I'll keep this post updated for future reference.