I'm not sure if this helps or in any way relates to your situation, but the power steering in my jetta is quite broken. It is apparently overpressurized due to a problem in the rack. When I got it the reservoir was cracked and most of the fluid had leaked out. The pump was absolutely screaming. So, I replaced the reservoir and the pump so now the pump is making noise again and the steering is downright scary. It feels like it wants to steer for you, not just assist. So, I'm going to change the rack now since it's the last part of the equation.