88 convertible, stock.

My power steering has been acting funny, at least I think thats what is doing it. I have a topped off power steering fluid resevoir..

Sometimes it will be extremely easy to turn the wheel (at a stop or 60mph+ or around a turn) and sometimes it will be quite difficult (at a stop or a low or high speed turn).. it seems to be random, I can't quite figure it out. Is my pump going? or.. what?

 

Sounds like the pump. I had a pump go out on me before, and it was intermittant(sp?) at first.,

However, I have also had a belt start slipping, and didn't get enough grip on the pump, and had the same symptoms.