Brake Problems With Electric Vehicles And How To Avoid Them

AutoGuide.com Staff
by AutoGuide.com Staff

If you spend any time driving an electric car, you know that they very rarely use their conventional braking systems. One-pedal driving or not, the powerful electric motors that drive the vehicle also stop your EV in most situations. While that sounds great for brake life, it also poses new challenges for EV owners. Here are those electric vehicle brake problems, and how the folks at NRS Brakes can help you avoid them.

The brakes on your car, truck, or SUV are one of the most exposed components of your vehicle. The most important parts, like the brake rotor surface, brake pads, and caliper slide pins, are exposed to the elements at all times.

You’re probably thinking “well so is my car’s hood, and that’s not a problem,” and you’d be right. The difference is that your brake parts aren’t protected like your vehicle’s bodywork.

They can’t be. Any coatings on the friction surface quickly wear off, so the brake parts sit exposed to rain, salt, and debris. Brake components rust so quickly that you can actually see that rust if you park outside and it has rained overnight.

In a gas-powered car, that’s not a problem. You use your brakes every time you touch the brake pedal and that rust is quickly scrubbed away. More than just friction, there is heat, and that heat evaporates the water helping prevent more rust and corrosion. Equally importantly, your braking system gets used. Parts move and slide and stay lubricated.

On an EV, thanks to regenerative braking, you could easily go weeks or months without really using your brakes. In perfect conditions, this means they’ll never wear out.

In the real world, those parts will rust.

When it comes to brake rotor rust, there’s not much you can do. It’s also not really a problem. You might notice one morning that you can hear a rhythmic grinding noise at one or more of your wheels. This will probably wear away after a few miles of driving. If it doesn’t, you can try – in a safe location – to make a couple of emergency stops. This should engage your EV’s friction brakes and rub off the surface rust.

Brake pad rust is a bigger issue. Brake pads haven’t changed much in decades, at least not until NRS released its galvanized brake pads for EV s. Conventional brake pads have a thin steel backing plate with a thin coat of paint and a friction material glued to the front. They’re expected to wear out in just a couple of years, so long-term durability isn’t important.

On your EV, those pads should be able to last years because regenerative braking means they don’t get worn down. But the thin paint coating means rust starts almost instantly and doesn’t stop. The backing plate corrodes and flakes apart, eventually pushing away the plate and the pad material. Now your brake pads have failed and you don’t know. You might find out when they start dragging, slashing your electric range. Or you might find out when you need to make an emergency stop and the brakes can’t stop the way they should.

NRS Brakes solved that problem with its brake pads designed specifically for electric vehicles. The backing plate of the pad is galvanized. Coated with a layer of zinc, this is the same level of rust protection used to stop ships from rusting in salt water and to protect steel used outdoors in fences and playgrounds.

The zinc coating means NRS brake pads won’t rust prematurely. Designed to last as long as the friction material, these will give you the service life you’re expecting from your EV’s brakes.

To stop the pad surface and backing plate from separating, NRS said no to adhesives. Instead, NRS EV brake pads use a special mechanical bond. Where the friction surface is mechanically attached to the backing plate, using patented technology. Making sure they can never delaminate like a conventional pad.

The last EV brake problem is your sliding parts. Your mechanical brakes squeeze brake pads against the central rotor, slowing your vehicle. The caliper, which holds your brake pads, slides against its mounting. Usually on two pins called slide pins.

Because these pins need to allow your brake caliper to slide in and out, they need to be lubricated with a special grease. Over time, this grease breaks down or is washed away by rain and debris. When this grease fails, your braking system can seize in place. Usually with one brake stuck fully engaged, dragging that wheel. That’s bad for range and your brakes, and can lead to a fire. Even if it fails while disengaged, it means you’re missing a quarter of your brakes.

There is one fix, and one way to help reduce the risk of failure. The fix is to service your brakes regularly. Most EV manufacturers, even Tesla, recommend you service your brakes at least once a year. During this service, all moving parts are cleaned and re-lubricated as needed.

On some performance EVs, another more advanced brake caliper is used. Called a fixed caliper (versus a sliding caliper), a fixed brake caliper has clamping pistons on the inside and outside of your brake rotor instead of just the inside. Here, only the pistons move, so there are no sliders to lubricate. These still need service, but since only the brake pads move, the risk of failure is less.

Combined with NRS galvanized brake pads, fixed callipers can solve most of the brake problems facing EVs. While you can’t economically swap your sliding calipers for a fixed unit, you can upgrade your brakes to NRS galvanized pads and help add worry-free service life to your EVs braking system.

AutoGuide.com Staff
AutoGuide.com Staff

More by AutoGuide.com Staff

Comments
Join the conversation
 2 comments
  • Shade Treemechanic Shade Treemechanic on Aug 13, 2022

    Lots of good cars have dual pistons. Fixed calipers are nothing new. Zinc can disappear fast when exposed to errant Elactric currents. Why not use SS plates and pins. Long article with second rate information.

  • GJuan Johnson GJuan Johnson on Jan 09, 2023

    Brand new 2023 Bolt EUV. A friend bought the same car a week later. When coming to a stop, using brake pedal, (not doing it with paddle or regen pedal), there is a grabbing rubbing feeling/sound. I attribute if to new brakes, or maybe the frequent rain, construction concrete dust, etc. I know from experience cars will make all kinds of brake noises if you buy cheap pads. I did have one brand new Ford LTD where the rotors were rusted so bad in a new car, all four had to be replaced. I may take it back to the dealer after the rains have stopped. There is quite a few manufacturers now that advertise "quiet" brake pads that are supposedly better than OEM. Thanks for the well written article.

Next