Recently I noticed that when my car about to come to a complete stop, there's a tiny squeaking sound. The sound is similar with what provided in this video, at 1:18 mark The sound not appear immediately when I apply the brake. It only appears just before the moment the car is completed stop, in short interval and really really tiny. Can only hear it if you pay attention and turn off the radio I thought it was brake pads but in the video that guy said it only happen when NOT apply brake or put the car in reverse, so I'm a little bit confused I lived in Seattle and it's been raining for the whole week recently, if this information might help you
The first thing to note is that the video you linked describes braking systems in a non-hybrid car. The Prius is different. It only applies mechanical brakes when the regenerative braking system (i.e. the resistance to rotation in the Motor Generator) cannot supply enough braking power to match the pressure you are putting on the brake pedal, except that the system will always apply mechanical brakes when the speed of the car becomes less than about 7 mph. This could explain why you are not hearing squeaking at higher speeds, it may not be using much mechanical braking at those higher speeds. In any event, the best advice we can give you is to have the pad thickness checked at a brake shop to make sure the pads do not need to be replaced. If the thickness is at or above specs for your car, you probably have nothing to worry about, unless you are noticing a loss of braking power, in which case you may have some glazing, as described in the video. Also, if the pads have gotten wet, as is a possibility if you have been driving in heavy rain, you will hear some noise (which can probably described as a type of squeaking) when the pads first come in contact with the rotor, but that should diminish as you continue to use the brakes and the pads dry out. Are you sure the squeaking is coming from the front? Our Gen 2 has a squeak that is noticeably coming from the back brakes, especially when we are reversing. It is possible the brake shoes on the rear of our car need to be replaced, but since the emergency brake still does a good job of holding the car on a hill, I'm not going to worry about it for now.
In addition, check that both anti-squeal shims are fitted and fitted correctly as well as the correct amount of brake shim grease applied between the shims.
Tiny squeaking noises from brakes is NOT something to worry about. Really it is not. Perfectly normal. When nobody is behind you, try one or two "hard" stops and see if the noise doesn't go away for a while.
The good thing about hybrids is that the brakes are not used as much and don’t wear out, the bad thing about hybrids is that because the brakes aren’t used as much they often need replacement from seizing. I usually use the brakes hard once a month or so on empty road at 45 mph to keep them freed up.
