With a growing number of electric vehicles on the road LIQUI MOLY is now offering Brake Fluid DOT 5.1 EV which is developed for the systems of modern vehicles that are also installed in EVs. 

Electric and hybrid vehicles have a brake system which usually requires the brake fluid to be changed every two years. David Kaiser, Head of Research & Development at LIQUI MOLY says, “But that’s about it for the similarities, with combustion engine cars because the requirement profile of the electric vehicles is sometimes completely different. That’s why we have developed the Brake Fluid DOT 5.1 EV. 

There are a number of reasons why brake systems are more demanding for vehicles that are partly or even purely electrically powered. “One is corrosion protection,” says David. “Because the electric motor also acts as a brake and uses it to generate energy for the battery, the mechanical brake system is used less frequently. This leads to spot corrosion.” Special additives counteract this effect.

David adds, “This does not mean that a brake system in an electric vehicle does only a little work. These vehicles are generally heavier than vehicles that are powered by an internal combustion engine and rapidly reach high speeds from which they also have to be braked abruptly in the event of danger. As a result, the brakes quickly become very hot. Brake fluids such as our new DOT 5.1 EV have to be effective even when the brake system is hot and therefore require a high dry and high wet boiling point.”

There is also the question of possible electrical conductivity. This plays a role if an electrical system is installed near the brake system and is not sufficiently shielded. As with the wireless, inductive charging of a mobile phone, electrical voltages can then be induced in the brake system, which can decompose the brake fluid or promote corrosion.

DOT 5.1 EV also has a low viscosity which transmits the braking pulses in the system more quickly, meaning the electronic driver assistance systems such as ABS or ESC function better and respond even more sensitively. 

David concludes, “As with motor oils only use brake fluids that meet the correct approvals and specifications. 

LIQUI MOLY Brake Fluid DOT 5.1 EV is now available from stockists.