With regenerative braking systems reducing reliance on traditional brakes, many electric and hybrid vehicle drivers assume their brake components experience less wear. And although friction brakes on EVs and hybrids are used less often, they can still suffer from brake fade just the same as conventional vehicles.
It’s a critical safety issue that affects not just performance driving and heavy loads, but also everyday stop-start traffic.
What is brake fade?
Brake fade refers to a temporary and sudden loss of braking power caused by excessive heat build-up within the braking system. The components themselves – pads, discs, brake fluid – might still be in good condition, but the system simply gets too hot to function effectively.
This results in a noticeable drop in stopping power, which can put the driver and others at risk.
Typical signs of brake fade include:
- Longer stopping distances
- A soft or spongy brake pedal
- Burning smells or visible smoke from the brakes
- Vibration or judder under braking
Why does brake fade happen?
Whether petrol, diesel, hybrid or electric, all braking systems rely on friction to slow the vehicle, and that friction generates a lot of heat. Under normal conditions, the heat is dissipated quickly but under sustained or repeated braking, especially from high speeds or when carrying heavy loads, it can build up faster than it can escape.
In electric and hybrid vehicles, brake fade can occur for slightly different reasons:
- Lower friction brake usage due to regenerative braking can lead to corrosion or contamination on discs and pads.
- High vehicle weight, due to heavy battery packs, places extra demand on brakes when they are used.
- Lack of regular friction brake use may mean the system isn’t fully bedded in or maintained.
The different types of brake fade
Brake fade can occur in more than one way, so understanding the specific type can help with diagnosis, prevention, and reducing the risk of spongy pedal feel, reduced braking efficiency, dramatic loss of braking power, uneven disc wear, or juddering.
- Pad fade (or friction fade)
- Occurs when brake pads exceed their temperature range
- Resin binding agents break down, releasing gas
- A thin layer forms between pad and disc, reducing grip
- Fluid fade
- Brake fluid absorbs moisture over time
- Under intense braking, it can boil, turning water to vapour
- Vapour is compressible, making the pedal feel spongy or unresponsive
- Green fade (early-life fade)
- Happens with new brake pads that haven’t been bedded in properly
- Resin in new pads releases gas under heat
Why EVs and hybrids are particularly susceptible
Regenerative braking, while beneficial for energy recovery and component longevity, reduces the frequency and intensity with which traditional brakes are used. This can result in:
- Surface corrosion on infrequently used rotors
- Glazing of brake pads, where surfaces harden and lose friction
- Unexpected underperformance when switching from regenerative to friction braking in emergency situations
EVs also weigh more than their conventional counterparts, meaning the brakes work harder when engaged – compounding the risk of fade under load or on long descents.
How to help prevent brake fade
- Good driving habits and regular maintenance are key to reducing brake fade risk:
- Use engine braking or regenerative braking downhill, but don’t rely on it exclusively
- Downshift where possible to maintain control without overheating the brakes
- Avoid riding the brakes, especially in slow-moving traffic or on inclines
- Bed in new brake pads correctly by following the manufacturer’s guidance
- Replace brake fluid regularly – even in EVs, where usage is lower, the fluid still absorbs moisture over time
- Fit high-quality, EV-specific brake pads and discs where possible
- Reduce unnecessary weight in the vehicle to ease braking demand
Brake fade isn’t limited to performance cars or extreme driving conditions. It can happen in everyday driving – especially in electric and hybrid vehicles, where braking systems behave differently to traditional ones. And although regenerative braking is a valuable tool, it doesn’t remove the need for well-maintained friction brakes.
By understanding the causes and signs of brake fade and adopting preventative measures drivers can ensure their vehicles stop as effectively as they go.