1998 Chevrolet Venture Owner's Manual - Page 362

There are only two reasons why the brake fluid level in the reservoir might go down. The first is thatthe brake fluid goes down toan acceptable level during normal brake lining wear. When new linings are putin, 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 yourbrakes won't work well, or won't work at all. 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. I A CAUTAN: 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 others could be burned, and your vehicle could be damaged. Add brake fluid only when work is done on the brake hydraulic system. BRAKE United States Canadian When your brake fluid falls to a low level, your brake warning light willcome on. See "Brake System Warning Light" in the Index. 6-27