2003 Chevrolet Astro Owner's Manual - Page 260

Checking Brake Fluid I I DU have toc ..Iuc.. >rake fluid, it can spill on t 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 i done on the brake s hydraulic system. See "Checking Brake Fluid" in this section. MIN / \\ \ Refer to the Maintenance Schedule to determine when to check your brake fluid. See Part C: Periodic Maintenance Inspections on page 6-30. You can check the brake fluid without taking off the cap. Just look at the brake fluid reservoir. The fluid level should be above MIN. If it isn't, have your brake system checked to see if there is a leak. After work is done on the brake hydraulic system, make sure the level is above the MIN but not over the MAX mark. 5-43