Regenerative Braking Systems: A Whole New Ball Game

by | May 24, 2022 | 0 comments

While the proportion of vehicles on the road made up of EVs (BEVs and hybrids) is still relatively small, the use of regenerative braking systems places particular challenges on suppliers and service professionals, due to the longevity of the brake friction on the complexity of the systems. What does this mean for jobbers and their asp customers?

EVs and hybrids use a completely different technology when it comes to stopping the vehicle. And that’s why brake pads that are specifically made for use on electrics are completely different from friction made for conventional vehicles and are not interchangeable.

A recent article by the brake manufacturer NRS summed up the key differences this way.

“Gas-powered cars, trucks, and SUVs use their hydraulic brakes every time they stop. As part of stopping, they turn your vehicle’s forward motion into heat where the brake pads meet the rotors. Those brake pads are designed to wear, shedding particles of material every single time they’re used to help dissipate the intense heat. After 40-50,000 miles, or just a few years of driving, the pads are worn out and need to be replaced.

“An EV, plug-in hybrid, and even a conventional hybrid, all use their electric motors to handle nearly all of the vehicle’s braking. Using their electric motor to generate electricity instead of powering the wheels, they turn the motion of the vehicle into heat and electricity, using that electricity to help recharge the battery and recapture some of the energy used to get you moving.”

Continental, which makes ATE brake pads for electrics and hybrids, along with other brake components, points out that automotive braking systems are comprised of several different components that allow smooth and reliable function. “In the case of EVs, the wear parts, such as disc brake pads and rotors, last considerably longer than those used on traditional gasoline vehicles. In spite of this fact, however, other components that make up the brake system still need to be inspected and serviced. That’s why at Continental, we are constantly promoting the need for brake system inspection and service in our training efforts, on our websites, and in our ongoing messages to our distribution partners and their service professional technician customers.”

NRS points out that with no oil changes, no timing belts, and most of the other expensive upkeep of an internal combustion system eliminated, your EV won’t spend much time on the lift at your mechanic’s shop for maintenance. Regenerative braking, a system that allows EVs to use their electric motors to slow the car instead of conventional brakes, is a big part of that. But this does add a new issue EV owners should be aware of: There’s a risk that needed service may go undetected, simply because there’s no impetus for the consumer to take the car in for regular service as often.

It’s imperative that owners of these vehicles understand that there are still numerous mechanical systems that need regular inspection and maintenance – including the brake system.

Continental again: “A key issue we see a lot is brake fluid. This basic component of the brake system is often overlooked during regular service, and can be the culprit in a variety of brake system problems. Brake fluid is hydroscopic, which means it absorbs water. Over time, excess water will lower the boiling point of the fluid, and that can affect how the brake system feels and how well it performs. The standard service life of brake fluid in any vehicle is two to three years. Optimally, this means that the fluid should be changed every two to three years and replaced with fresh, new brake fluid from an unopened container. 

“In addition to brake fluid service, mechanical parts such as master cylinders, brake lines, and calipers should also be inspected and serviced as needed. In areas with road salt or high corrosion, rust can develop on the calipers or brake pad backing plates, along with corrosion of the slide pins. All of this can affect the proper performance of the braking system. So, although brake systems’ wear components are replaced most frequently, there are many other components that should come to play as a part of routine maintenance.”

Continental goes on to advise that it’s up to jobbers to be aware of the different components  of the specialized EV brake system, how they work together to assure proper performance, and the inspection and maintenance of each part. “When orders come in for routine replacement of wear parts, they should be prepared to promote the need for overall system check, especially in those areas where service is typically underperformed. It makes good sense to follow up a brake rotor order with a brake fluid suggestion. There’s a good chance that rotor is at least a couple of years old, and that could be a good indicator for the age of the fluid.”

Furthermore, as NRS points out, the long life of EV brake pads can actually introduce other problems. “Brake pads live close to the road, so they see some of the worst conditions the vehicle sees. Water, mud, dirt, and road salt are all being thrown at the brake pads every time you drive. This creates an environment that is the perfect place for corrosion to thrive.”

The solution is brake pads that are specially designed to address these unique needs. NRS’s specialized EV brake pads rely on galvanized steel to resist the build-up of moisture, road salt and other rust-causing chemicals that can cause corrosion and rust. Also, instead of adhesives, NRS brake pads have in-situ galvanized hooks, called NRSTM, on the backing-plate surface. These hooks provide a mechanical retention of the friction material, overcoming inadequacies of adhesive usage. This guarantees that the friction material will never delaminate, providing a longer life and safer brake operation for the entire life of the pad.

Another brake pad designed especially for electrics by ZF Automotive, under the TRW Electric Blue brand, is aimed specifically at the aftermarket, in a high-quality, copper-free product with a high degree of reduction in noise, vibration and dust emission levels – higher, in fact, than the OE spec – that won the “Best New Hard Part” distinction at last year’s AAPEX. The line covers virtually all electric and hybrid vehicles currently available in North America.

Although at this writing electrics and hybrids may still be still relatively new territory for many Canadian service providers, it’s not going to stay that way for much longer.

It’s imperative that jobbers ensure that their service provider customers have the training and information they need on EV/HEV brake systems and components, including keeping them abreast of promos and POS literature.

As Continental advises, “They should also encourage their professional customers to consider the entire brake system when their customer is in for maintenance on the friction components. This includes regular brake fluid changes and service of mechanical parts like calipers and slide pins.”

This article also appeared in the April/May print edition of Jobber Nation which can be read HERE


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