Hybrid and Plug-in Hybrid Electric Vehicles Brake Fluids
Hybrid and plug-in hybrid electric vehicles (PHEVs) do require specific types of brake fluids formulated to meet their unique braking system demands. The main considerations for brake fluids in these vehicles include high boiling points, low viscosity, compatibility with seals and gaskets used in electric/hybrid brake systems, and good thermal stability to handle high temperature fluctuations associated with regenerative braking systems.
Recommended Brake Fluids for Hybrid and PHEV Vehicles
- DOT 5.1 Brake Fluid:
Many manufacturers and suppliers recommend using DOT 5.1 brake fluid specifically formulated for hybrid and electric vehicles. Examples include FERODO DOT 5.1 EHV and EV-FLUIDS BRAKE FLUID DOT 5.1 by Repsol. These fluids offer high boiling points (both dry and wet), low viscosity, and are compatible with electric and hybrid vehicle brake system components, including seals and gaskets. Their formulations also work to prevent foam formation and provide excellent thermal stability, extending the intervals between changes. - Special Polyglycol-Based Fluids:
Some companies, like Gulf Lubricants with their eLEC brake fluid, have developed polyglycol-based brake fluids designed specifically for electric and hybrid powertrains. These fluids emphasize high boiling points, corrosion protection, and performance tailored to the demands of regenerative braking systems, which put different stress on the braking system compared to conventional vehicles. Such fluids ensure reliable braking performance even when the battery is fully charged and regenerative braking is limiting friction brake use, which increases the need for corrosion resistance. - Liqui Moly DOT 5.1 EV Brake Fluid:
Liqui Moly also offers a DOT 5.1 brake fluid variant developed for modern vehicle braking systems used in electric vehicles, indicating a trend toward specialized fluids for these drivetrains.
Why Special Brake Fluids Are Needed for Hybrids and PHEVs
- Regenerative Braking Influence:
Regenerative braking reduces use of friction brakes, lowering brake wear but increasing the risk of moisture build-up and corrosion in the brake system. Special fluids ensure corrosion resistance and maintain performance even with reduced brake use. - Thermal and Electrical Characteristics:
Hybrid and PHEV brake fluids require higher boiling points to handle thermal loads during intense braking and quick thermal changes. Also, lower conductivity fluids are preferred to protect sensitive electric brake components. - Compatibility with Components:
Since hybrid and electric vehicles often use specialized brake system materials, compatible fluids prevent seal deterioration and fluid contamination.
Summary
Hybrid and PHEV vehicles benefit from brake fluids specifically engineered for their systems, with DOT 5.1 fluids being the most commonly recommended. These fluids provide high boiling points, thermal stability, anti-foaming properties, and compatibility with electric brake system components. Specialized polyglycol-based fluids are also available to meet corrosion resistance and performance demands related to regenerative braking. Using such fluids ensures optimal braking reliability and longevity of the brake system in hybrid and PHEV vehicles.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/are-there-specific-brake-fluids-recommended-for-hybrid-and-phev-vehicles/
