Remove the pads. Clean the pads front and back with brake cleaner being careful not to get any brake grease on the pad surfaces. Clean the rotors with brake cleaner too. Apply fresh brake grease to the rear of the pads and pad carriers. Basically, any place the carrier touches the pad, and any place the carrier touches the caliper, should get fresh grease. (Use brake grease and not any substitute. No other grease will stand up to the heat.)
I had a 1998 RAV4 that developed squealing brakes after I put a few thousand km on it and they squealed until the day it got totaled in the Calgary flood of 2013 (with only 110,000 km...I don't drive much). For me it's too much of a coincidence that the brakes were fine until after I took it in for servicing. Wondering if the mechanic didn't tighten things up properly after greasing the calipers.Brakes are sensitive to temperature. Too hot or too cold can cause squeals and are considered normal. I had double to brake checks for squeals in the summer and winter than falls and spring. 95% of them I could do nothing about it.
the brakes on my wife's mazda2 have been squealing since day one when cold... took it to the dealer and they can't find out the issue (i think they just didn't want to fix it)... i figured it's the brake pads.. as soon as my current ones wear down, i'm switching them out for some wagner thermoquiet pads.. i use those on all my other cars