Hello, squealing, in general occurs when the brake pads move every so slightly in the disc brakes and resonate on the calipers and brackets, or when pad material mating to the brake rotors are burnished in well or properly. Also, environmental concerns can lead to brake squeal. Some is, in fact, normal and unavoidable. Rear drum brakes are also susceptible to brake noise because the shoes are inside the brake drums and the brake dust from wear will collect in there in normal use. This is also unavoidable.
I will say, though, that a few things lead to more frequent and annoying brake noise:
1) Inferior brake pads used. Low quality brake pads make more noise.
2) Non original Chevrolet brake pads will not fit perfect like original Chevrolet pads, leading to more movement and noise potential.
3) Brake pad shims missing, loose, or not provided
4) Anti-rattle clips missing or mis-installed or loose
5) Brake rotors have hot spots that have not been resolved
6) Brake rotors were not properly resurfaced with an on-vehicle brake lathe when replacing brake pads
7) Brakes that overheat due to brake rotors that are too thin to safely use or brake fluid that has not been regularly replaced (every 2-3 years) will increase brake noise.
Those are most common. Rear brake drums can also be noisy due to drums that are oversized as well due to normal wear out. They should be measured for inside diameter. Brake shoes can crack or be out of adjustment, causing more stress on the front wheels, resulting in brake overheating and noise.
So -- without knowing what happened during the "new brakes all the way around" installation, and what materials were used, and what process was followed -- it's a mystery to me. Those are just clues and possible causes.
Seek guidance at a local shop near you for a good inspection and evaluation.
Use this link to find some shops near you that can help with your concern:
www.repairpal.com/repair-shops
