1995 Pontiac Grand Prix Owner's Manual - Page 238

Brakes Brake Master Cylinder Your brake master cylinderis here. It is filled with DOT-3 brake fluid. fluid is leaking out the brake system. Ifit is, you of should have your brake system fixed, since a leak means that sooner orlater your brakes won't work well, or won't work at all.So, it isn't a good idea to "topoff' your brake fluid. Adding brake fluid won't correct a leak. If you add fluid when your linings are worn, then you'll have too much fluid when you get new brake linings. You should add (or remove) brake fluid,as necessary, only when work done on the brake is hydraulic system. There are only two reasons why the brake fluid level in your master cylinder might down. The first is that the go brake fluid goes down to an acceptable level during normal brake lining wear. When newlinings are put in, the fluid level goes back up. The other reason is that When your brakefluid falls to a low level, your brake warning light will come on. See "Brake System Warning Light" in the Index. 6-25