Groaning Brakes

jeep
brakes
liberty
noises

#1

I own a 2006 Jeep Liberty Limited. 3 weeks ago I smelled my brakes burning and took it into the shop. They replaced the right rear caliper, replaced both rear brake rotors, replaced the right rear brake pad, and did a brake flush. A week later I noticed a groan when I would hit the brakes for the first time after starting the car up and traveling around 5-10 MPH. I also noticed a very faint high-pitched groan whenever I hit the brakes between 15 and 30 MPH. This has continued the last two weeks. I thought it was the fact that I had new pad and rotors but am worried since it’s been going on a little while. Since I live in the city I hit the brakes a lot.