How do I know if it's failed or if I just have air in the line? I know the PS system has a leak as I have to regularly add some PS fluid every so often (about every 2 months or so). I know having a leak is potential for having air in the line, however, if I have air in the line I know that the PS fluid is supposed to foam up. Mine doesn't. The reason why I question if it's the PS pump itself is because even when the reservoir is full of PS fluid the PS pump is making a whining noise with the noise getting worse whenever I turn the wheel. Also note, that when I initially turn on the car, there is no noise at all for the first 15 seconds or so. I'm leaning on the pump having gone bad (it is original to the car, 317k), but if I also have a leak, I'd like to know where these leaks may be coming from. I know of the common leak at the high pressure hose to PS pump point with the o-ring failure, but are there other areas that I could be leaking from that are also fairly common to see on these cars?