1997 Oldsmobile Achieva Owner's Manual - Page 261

There are onlytwo reasons why the brake fluid level the in reservoir might go down.The first is that the brake fluid goes down to an acceptable level during normal brake lining wear. When new linings are put in, the fluid level goes back up.The other reason is that fluid is leaking out of the brake system.If it is, you should have your brake system fixed, sincea leak means that sooner or later your brakes won't work well, or won't work all. at So, it isn't a good idea to "top off' 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 is done on the brake hydraulic system. BRAKE U.S. Canada When your brake fluid falls to low level, your brake a warning light will come on. See "Brake System Warning Light" in the Index. If you have too much brakefluid, it can spill on the engine. The fluid will burn the engine if is hot enough. You or others could be burned, and your vehicle could be damaged. Add brake fluid only when workis done on the brake hydraulic system. 6-31