Nissan Repair: Brake squeal, brake squeal, frontier 3

Question
Hello, Ihave a 2001 Frontier 3.3, 88000 miles. When the brake pedal is pressed, even stopped, a squealing or howling noise can be heard. It will quit if pressed hard, but does it as the pressure is released. Does not seem from the fact it does it when stopped to be wheel-related. Any idea and anything a total novice might tackle? Thank you in advance!

Answer
Mike,

If there is noise, even when the vehicle is stopped, when the brakes are pressed, would lead me to think either the master cylinder is leaking out when the pedal is pressed or the ABS unit is doing strange things.  Now, if there was noise when the vehicle is moving and not when it is stopped would lead one to think the brake pads need to be replaced.