Diesel To avoid damage to your engine and diesel injection system it is essential to use only high grade diesel Brake Fluid Glycol-based brake fluid should be flushed every 1-2 years as it attracts and holds water molecules causing rust. Anti-Freeze Should be measured with an enthlene glycol hydrometer and renewed when measurement is at -5 celsius / 3 years or 40 000km. Battery Use a hydrometer to test cells before water is added. Servicing of batteries will prolong its life cycle. Airbag Systems Pyrotechnic systems have a limited service life. If the system has passed its renewal date, the overall safety protection is diminished.