1. Park your vehicle on a level surface and turn off the engine. Allow the engine to cool down completely.
2. Open the hood of your vehicle.
3. Locate the brake fluid reservoir. On the 2002 Ford Explorer, the brake fluid reservoir is located on the driver's side of the engine bay, near the firewall.
4. Check the brake fluid level. The brake fluid should be between the "MIN" and "MAX" marks on the reservoir.
5. If the brake fluid level is low, add enough brake fluid to bring the level up to the "MAX" mark. Use only DOT 3 or DOT 4 brake fluid.
6. Replace the cap on the brake fluid reservoir.
7. Close the hood of your vehicle.
Note: If the brake fluid level is consistently low, it is important to have your brake system inspected by a qualified mechanic to identify and repair any leaks.