Hi guys hope you can help???

I have a 2004 Mazda 6 V6 3L.
The day my warranty expired I have had a problem with my car at full steering lock.

If pulling into a parking space and applying slight brake pressureI have noticed a loud low pitched squeal, not like a brake noise. More like i have turned too far and the wheels are making a noise. (sorry its a hard noise to explain)

I do need new tires whichI will be getting soon, could this cause a noise or is it more likely to be the power steering belt?I have checked power steering fluid and all is good there.

I have also got a nasty screeching brake whichI cant seem to stop,I have replaced the pads which seem to cause the problem, since then i have taken them apart and sprayed some 'brake noise stop' fluid on them, which had some effect but the screeching is still present.

Any ideas what the noise could be on full lock and any ideas on how to stop the front brake screech would be great.

Thanks guys, hope you can help me.