'08 JK, Auto, 47k miles.

In the warmer months, I'm almost afraid to pull into a parking spot - when moving slowly and turning the wheel, sometimes the steering will hesitate for just a quick moment. It's now cold outside, and my power steering feels like it is brand new.

PS fluid is clean and at proper levels.

There's never any whining or moaning - it just "grabs" when ambient temp is say 60+.

I was about set to replace the pump, but since it works so well when it's cold outside, I'm thinking more along the lines of bubbles in the system?

Appreciate any thoughts!