When it comes to safety-critical systems, brakes is one of the most important. But with the automotive market going through a period of rapid development, how is the braking market adapting to these changes? Auto Repair Focus Editor Phil Curry finds out.
Any moving object eventually needs to stop. The faster the speed, the more force is required. The braking market has been developing alongside the automotive industry for decades. From wooden blocks to modern friction compounds, suppliers have found new ways to stop cars, and keep occupants safe.
Today, however, the automotive market is going through some of its biggest changes. Electrification and sustainability are important considerations in new-model launches, and regulation development. But will this change braking, or will technicians be able to depend on the skills they know today, to ensure they can work on the cars of tomorrow.
Watch the latest Auto Repair Focus feature, Developments in the Braking Market, below, or on our YouTube channel. You can also subscribe for free to stay up to date with our future content.
“I do not think that braking has changed that much over the last decade,” commented Graeme Ryder, Group Technical and Quality Manager at Alliance Automotive Group. “The principles have remained pretty much the same over the years and I do not really see it changing much.
“Having said that, obviously there is a lot of progression towards improving the efficiency of braking and the sustainability. We also have a lot of hybrid and electric vehicles now, so we have got the regenerative brake system within them. But we are still using generally discs and pads to perform that function.
“So the braking market is not going to change that much. Technology will just develop, and we will move along and progress with it.”
Keeping brakes quiet
Customer expectations around brakes are changing, especially when it comes to noise, vibration and harshness.
A car should leave the workshop with no noise coming from the brakes. But new technologies and developments in other automotive areas are making these demands slightly more difficult.
Examples, pointed out by TMD Friction, include the lack of engine noise with electric vehicles, which therefore requires quieter brakes. At the same time, lightweight construction concepts are more prone to squealing and rubbing, regardless of the drivetrain. SUVs also have their pitfalls, as they have longer suspension arms that are more sensitive to low-frequency vibrations such as creep groan.
Automatic gearboxes as well as driver assistance systems can also lead to noise, vibration and harshness problems which can cause drivers to come to the workshop seeking help.
“People often assume that the brake pad is to blame, wrongly,” stated Hartmut Kießling, Technical Sales Manager and trainer at TMD Friction. “It is often actually worn suspension parts, or parts that deviate greatly from the original equipment. These vibrate audibly when the driver applies the brakes,” he says. “These cases require expert knowledge to determine the root cause.”
Grease or no grease?
One way of reducing potential squeal, as well as lubricating brake components when servicing, has been to use copper grease. But over the years, with changes in friction materials, this is now an outdated practice.
“The number one rule is do not use copper grease,” stated Ryder. “I have been telling technicians for my whole career that they should not be using it. But they have been using it for 30 years and why should they change?
“Technology does move on. So it is important that we do not use copper grease, but we do need to lubricate the pad at the abutment points to aid free movement. So we would recommend a copper-free, metal-free, high melting point petroleum-based grease for the brake pad environment and a silicon-based grease when you are lubricating the slider pins. It is important to clean the slider pins as well and obviously re-lubricate them.”
Regenerative brakes
The biggest change to brake systems is the electric vehicle. With regenerative braking, they are using their pads and discs less, meaning less wear and tear.
“For your general motorway driving, for your around town driving where you are not really needing to press on the brakes, you are really not going to be using the friction brake in those situations,” highlighted Matthew Ellis, Product Development Manager at Allied Nippon.
“A lot of newer EVs are also coming with a one pedal drive, where if you push down you accelerate, and if you lift off, not only are you decelerating, but actively braking through the regenerative braking system. Friction brakes, in the traditional sense, are only going to be used on EVs in extremely low deceleration situations.”
In addition, EVs are heavier than their internal combustion engine counterparts. “With that, obviously, the force and energy requirement to dissipate by the brake increases quite substantially,” added Ellis. “So really, you need a brake you can absolutely trust in a situation where you are going to need those high deceleration moments and scenarios, but also with a very, very high energy, heavy vehicle that you’re looking to stop.
Thinking about Euro 7
When it comes to sustainability, there is another factor to consider and that is Euro 7.
The new emissions regulation for passenger cars does not change much when it comes to exhaust output. But it is particulate matter, especially from brakes and tyres, that is under scrutiny.
Euro 7 comes into effect next year, and currently it is on carmakers to reduce pollution from friction materials. With brakes and tyres, this is known as PM2.5. These are fine particles that can enter the air or water, and cause health issues.
However, eventually the aftermarket will need to become aware of the regulations and reduce the output from friction materials. In the meantime, suppliers are already investigating what needs to be done, and technicians can help.
By bringing in quality brakes and discs from reputable sources, they are most likely to adhere to regulations. Not only will this help improve sustainability, but it also ensures the safety of the vehicle.
So it is not quite full stop yet in the braking market. Small changes are coming through, especially when it comes to maintenance methods, new ways of thinking about electric vehicle brakes or changing lubrication methods to ensure that we are moving away from copper grease.
But ultimately, as a safety critical item, the onus is on the technician and the garage to make sure that brakes are maintained properly.
