1999 Lexus LS 400 Owners Manual - Page 433

CHASSIS CHECKING BRAKE FLUID 63L001a To check the fluid level, simply look at the see-through reservoir. The level should be between the "MAX" and "MIN" lines on the tank. It is normal for the brake fluid level to go down slightly as the brake pads wear. So be sure to keep the reservoir filled. If the reservoir needs frequent refilling, it may indicate a serious mechanical problem. If the level is low, add FMVSS No.116 DOT 3 or SAE J1703 brake fluid to the brake reservoir. Remove and replace the reservoir cover by hand. Add brake fluid up to the "MAX" line. Use only newly opened brake fluid. Once opened, brake fluid absorbs moisture from the air, and excess moisture can cause a dangerous loss of braking efficiency. 417