Noise when AC is on
 

Hello group,


I drive a 2003 Mazda P5 with 150k + on it. The car drives great and I had maintained carefully.


After I had the water pump replaced a couple of weeks ago, I started to hear a noise coming from the rear when I back up from the parking stall and the AC is on. It happens only when the engine is cold in the morning and it lasts for maybe a couple of minutes. Mainly I hear it when I turn the wheel R or L and not when I drive straight. The guy who changed the pump says that I got a caliper issue but I am not sure at all if this is the case.
Could anyone here help with possibly pinpointing the noise issue?
Thanks much,

Are you positive its coming from the rear?

I am quite positive. The is a squiky noise that I hear when I back up or steer the car when the engine is cold.
I guess best way to describe it is a noise similar to the one that you hear when the tires rub a wet pavement when you break suddenly but is not that strong. It maybe related to the brakes although they are in fair shape....the funny part is that it happens only if I have the AC on...