1998 Oldsmobile Achieva Owner's Manual - Page 256

There are only two reasons why the brake fluid level in the reservoir mightgo down. The first is thatthe brake fluid goes down toan acceptable level during normal brake lining wear. When new linings are put in, the fluid level goes back up. The other reasonis that fluidis leaking out of the brake system. it is, you should have your brake If system fxed, since a leak means that sooner later your or brakes won't work well, or won't work at all. BRAKE I United States Canada 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 whenwork is done on the brake hydraulic system. When your brake fluid falls to a low level, your brake warning light will come on. See"Brake System Warning Light" in the Index. What to Add When you do need brake fluid, use only DOT-3 brake fluid -- such as Delco Supreme 11 (GM Part No. 12377967). Use new brake fluid from a sealed container only. @ If you have too much brake fluid, it can on the spill engine. The fluid will burn the engineis hot if enough. You or others could be burned, and your vehicle could be damaged. Add brake fluid only when work is done on the brake hydraulic system. I Always clean the brake fluid reservoir cap and the area around the cap before removing it. This will help keep dirt from entering the reservoir. 6-28