1994 Chevrolet Astro Owner's Manual - Page 251

To Check BrakeFluid You can check the brake fluid without taking off the cap. Just look at the windows on the brake fluid reservoir. The fluidlevels should be above MIN. If they aren't, have your brake system checked to see if there is a leak. After work is doneon the brake hydraulic system, make sure the levels are above MIN and below the top of each window. What to Add When you do need brake fluid, use only DOT-3 brake fluid - such as Delco Supreme II@(GM P r No.1052535). Use new at brake fluid from a sealed container only, and always clean the brake fluid reservoir cap before removing it. NOTICE: Don't let someoneput inthe wrong kind of fluid. For example, just a few drops of mineral-based oil, such as engine oil, in your brake system can damage brake system parts so badly that they'll haveto be replaced. Brake fluid can damage paint, so be careful not to spill brake fluid on your vehicle. you do, wash off immediately. See If it "Appearance Care" in the Index.