Replace the contaminated brake fluid in your 4BT 3.9L Diesel before it starts to affect your braking performance. Many manufacturers recommend replacing the brake fluid every 2-3 years or at specific mileage intervals. It is very important to follow the manufacturer's recommended service schedule as well as testing your brake fluid occasionally. Brake fluid is one of the most frequently ignored fluids when it comes to basic maintenance, despite the fact that brakes are one of the most important safety aspects of a vehicle. Despite being a closed system, brake fluid will eventually begin to collect moisture. As a result, the braking performance will begin to suffer due to the decreased boiling point caused by the water. Brake fluids are offered with varying specifications including DOT 3, DOT 4, DOT 5, and DOT 5.1. The most widely utilized braking fluids are DOT 3 and DOT 4. Even though the two brake fluids are compatible, DOT 4 has a higher boiling point than DOT 3. Shop XDP for all the top brake fluid manufacturers such as Lucas Oil, and more!