2008 Pontiac G8 Owner's Manual - Page 208

9-24 Vehicle Service and Care It is not a good idea to top off the brake fluid. Adding brake fluid will not correct a leak. If fluid is added when the linings are worn, there will be too much fluid when new brake linings are installed. Add or remove brake fluid, as necessary, only when work is done on the brake hydraulic system. Brakes Brake Fluid What to Add When you do need brake fluid, use only DOT-4 brake fluid. It is recommended that you flush the brake hydraulic system and refill it with new DOT-4 fluid at a regular maintenance service every two years. See "Additional Required Services" in the Maintenance Schedule. Use new brake fluid from a sealed container only. See "Recommended Fluids and Lubricants" in the Maintenance Schedule. Always clean the brake fluid reservoir cap and the area around the cap before removing it. This helps keep dirt from entering the reservoir. The brake master cylinder reservoir is filled with DOT-4 brake fluid. 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 hydraulic system. If it is, have the brake hydraulic system fixed, since a leak means that sooner or later the brakes will not work well. { 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 the brake fluid falls to a low level, the brake warning light will come on. See Brake System Warning Light on page 4-16. { CAUTION With the wrong kind of fluid in the brake hydraulic system, the brakes might not work well. This could cause a crash. Always use the proper brake fluid.