What should be monitored regarding the DEF tank?

Monitoring the DEF (Diesel Exhaust Fluid) tank for leaks is essential for several reasons. First, leaks can lead to a loss of DEF, which is crucial for the operation of modern diesel engines equipped with SCR (Selective Catalytic Reduction) systems. If the DEF is leaking, it may not be available in the right quantity to effectively reduce harmful emissions, potentially causing the vehicle to fail emissions tests or run less efficiently.

Additionally, leaking DEF can also pose environmental hazards, as the fluid is urea-based and can harm local flora and fauna if released into the environment. Ensuring that the DEF tank has no leaks helps maintain the integrity of the system and ensures that all components are functioning as intended.

While it is important to consider factors such as the heating of the DEF to prevent freezing in colder temperatures or utilizing a refractometer to measure the fluid's concentration, leaks pose an immediate risk to both vehicle operation and environmental safety. Overfilling the DEF tank is not advisable as it could lead to spillage or functional impairments within the tank system. Therefore, monitoring for leaks is the most critical aspect of maintaining the DEF tank.