PS fluid/ effort

One more problem or it might be me getting too worried without any reason.
Two weeks ago when it snowed like crazy in midwest, i went to parallel park my car. The snow(by then ice) was not cleared from the sides as there were cars parked. When I backed up to park I heard snow/ice hitting the bottom of the car. When I moved the car next day morning from my garage, I saw a puddle of power steering fluid. I checked the power steering fluid and it was low and i topped it off. Since then I have been keeping an eye on the PS fluid level and its been ok(may be a couple of drops on the floor). Somehow I feel the power steering needs more effort now.
Another thing that I felt was that when the ABS and tire pressure light was on, the steering was even harder.

Does some one has any explanation for this phenomenon.

Thanks in advance

Since the power steering hoses run near the rf tire, I would bet the snow/ice pinched the return hose slightly and caused it to leak. If the leak doesn't The ABS /trac off lights indicate a bad wheel speed sensor, and the EVO (elcectronic variable orifice) steering system uses wheel speed signal to increase boost at parking lot speeds. That is why steering effort has increased.