Where is the "brake fluid reserve" located on my 03 Buick park avenue ultra "supercharged six?

In the manual it tells me to check it along with all the other items listed. I cannot find it anywhere. I understand that if you hear it %26quot;spuealing a little%26quot; the fluid should be changed because it breaks down after xxx amount of miles. help|||usually it is on the firewall, on the drivers side, a small cap says brake fluid. I disagree with the squealing being due to the fluid, that is the brake shoes. I%26#039;ve also never heard of changing the brake fluid, Be careful , some one might tell you to lube your muffler bearings. Good luck!|||It%26#039;s the plastic reservoir on top of the master cylinder. It may be covered by a plastic shroud, but it will say %26quot;brake fluid only%26quot; DOT 3 etc.