Sometimes when I brake, I feel the brake petal stutter like it doesn't want to go down. I also heard a moaning noise. What could this be? The moaning sound sometime occurs when I turn.

I'm riding in an Oldsmobile Alero 2002 2.2 Liter engine

the brake thing sounds like a warped rotor.

the moaning sound most likly is a wheel bearing.

the bearings on these models are a combination wheel speed sensor & sealed bearing units.