1998 Pontiac Firebird Owner's Manual - Page 287

There are only two reasons why the brake fluid levelin the reservoir might go down. The first is that the brake fluid goes downto an acceptable level during normal brake lining wear. When new linings are putin, the fluid level goes back up. The other reason is that fluidleaking out is of the brake system.If it is, you should have your brake system fixed,since a leak means that sooner or later your brakes won't work well, won't work atal or l. So, it isn'ta good idea to "top off' your brake fluid. Adding brake fluid won't correct a leak.you addfluid If when your liningsare worn, then you'll have too much fluid whenyou get new brake linings.You should add (or remove) brake fluid, as necessary, only work is when done on the brake hydraulic system. Checking Brake Fluid A CAUTION: If you have too much brake fluid, can spill on the it engine. The fluid will burn if the engineis hot enough. You or others could be burned, your and vehicle could be damaged. Add brake fluidonly when work is done on the brakehydraulic system. Refer to the Maintenance Schedule to determine when to check your brakefluid. See "Periodic Maintenance Inspections" in the Index. You can check the brake fluid without takingthe cap. off Just lookat the brake fluid reservoir.The fluid level should be above the plastic seam in the reservoir.If it isn't, have your brake system checked to see if there is a leak. After workis done on the brake hydraulic system, make sure the level above the plastic is seam, near the base of the filler neck.