brakeing problem on 2003 Oldsmobile Alero

when brakeing over 40 mph, front end shutters

Asked by for the 2003 Oldsmobile Alero
Sounds like your brake rotors are warped or has hot spots and during braking it grabbing and releasing causing the shutter, You need to have the brakes inspected to determine exactly what needs attention and you can check brake rotor estimates here