2007 Buick Rendezvous Owner's Manual - Page 390

So, it is not a good idea to top off your brake fluid. Adding brake fluid will not correct a leak. If you add fluid when your linings are worn, then you will 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. What to Add When you do need brake fluid, use only DOT-3 brake fluid. Use new brake fluid from a sealed container only. See Recommended Fluids and Lubricants on page 485. 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. {CAUTION: If your vehicle has 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. When your brake fluid falls to a low level, your brake warning light will come on. See Brake System Warning Light on page 219. {CAUTION: With the wrong kind of fluid in the brake system, the brakes may not work well, or they may not even work at all. This could cause a crash. Always use the proper brake fluid. 390