1997 Buick Regal Owner's Manual - Page 305

There are only two reasons why the brake fluid level in the 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, since a leak means that sooner or later your brakes won't work well,or won't work at all. When your brake fluid falls tolow level, yourbrake a warning light will come on. See "Brake SystemWarning Light" in the Index. What to Add When you do need brake fluid, use only DOT-3 brake fluid -- such as Delco Supreme11 (GM Part No. 12377967). Use new brake fluid from asealed container only. @ So, it isn't a good idea to "top off' your brake fluid. Adding brake fluid won't correct a leak. you add fluid If 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. Always clean the brake fluid reservoir cap and the area around the cap before removing it. This help keep will dirt from enteringthe reservoir. 1 CAUTIC If you have too much brake fluid, it can spill on the engine. The fluid will burn if the engine is hot enough. You or otherscould be burned, and your vehicle could be damaged. Add brake fluid only when work is done on the brake hydraulic system. With the wrong kind of fluid in your brake system, your brakesmay not work well, or they may not even work at all. This could cause a crash. Always use the proper brake fluid.