The Problem With Ceramic Brake Pads.
If you drive a car one of the last things you want from your brakes is to be noisy or make the wheels dirty. When ceramic brake pads came out it solved the issue of dirty wheels and noise problems. For years we have been installing them with very few issues. Out of nowhere we started to have issues with noise and vibrations. What happened?
To understand what happened we need to discuss Ceramic brake pads, Semi-Metallic brake pads, and environmental regulations.
Brake Pad Construction
Years ago there were no regulations on brake pads. Manufacturers would grind up whatever they could find and put a bonding agent in the mix and press it into a brake pad. This process had very few regulations and as long as the brake didn't light on fire everyone was happy. This is where one of the first regulations started on brake pads.
Fire was a big problem in brake pads and there was a perfect fiber that was fire resistant that kept brake pads from lighting up, Asbestos. Asbestos was used for years to keep brake pads from lighting on fire. It was perfect for the application. There was one major drawback though, cancer. When it was found that asbestos caused cancer quality brake pad manufacturers decided to remove it from their brake pads. This is where the semi-metallic brake pad came in.
Semi-metallic brake pads are made up of metals such as iron, steel, brass, and copper. The brake pad is made up to 70% of these metals. The other 30% are other fillers and bonding agents to hold the mixture together. When these brake pads wear, fine particles of metal wear off the brake pad and brake rotor. The particles make their way into the air and some end up sticking to the wheel. Semi-metallic brake pads are known for causing a lot of brake dirt and making wheels turn black in no time at all.
The good part about semi-metallic brake pads is that they have very good stopping power during a wide range of braking. They are very resistant to brake fade and are the best choice for trucks and large SUVs. The big drawbacks are dirt and they can sometimes be extremely noisy. So what other choices are there to lower brake pad dirt and noise?
Ceramic brake pads are the answer to dirty wheels and noises. They are made of materials that closely mimic the pottery in your house and adhesives. They operate much differently than semi-metallic. As the pads heat up for the first time the brake pads apply a layer of the brake pad to the rotor. This allows the brake pad to “stick” to the rotor. Think of it like an envelope seal. The glue is there but it does not activate until moisture is applied. The Ceramic brake pads work the same way but with heat. When you step on the brake pedal it makes the pads hot and they become sticky. This is what stops the car.
For years all was well in the world of brake pads until the government stepped in. They had been studying waterways along highways and found elevated levels of copper. What was happening was Washington state saw that Salmon were having navigation and other issues caused by heavy metals in the water. They found increased levels of copper and other heavy metals were washing down from vehicle roadways and it was coming from brake pads. Washington and California were the first states to pass legislation to reduce the amount of copper and other heavy metals in brake pads. This started the Copper-Free Brake Initiative from the EPA.
The first part of the initiative was to reduce the amount of asbestos, cadmium, chromium, lead, and mercury in the brake pads. Some of these items had already been removed from brake pads but no legislation was put in place. This first initiative said the brake pads could contain no more than .1% by weight of these materials by January 1, 2015. The second part of this initiative was due to be in place by January 1, 2021. This was for brake pad manufacturers to be self certified that their brake pads contain no more than 5% by weight of copper. They must also reduce the amount of copper in the brake pads by .5% per year from 2021 to 2025. This means that January 1, 2025 brake pads must contain no more than .5% copper by weight.
To cut through all this slow reduction to phase out copper most brake pad manufacturers reformulated their pads to meet the 2025 requirements by mid 2016. This is where the problem started.
The importance of copper in brake pads
Remember when I described how ceramic brakes work by generating heat. Well the copper did a very important job in the ceramic brake pad. It scrubbed the face of the rotor keeping it smooth. It would remove any high spots or extra “glue” on the face of the rotor. The extra “glue” would happen when you would stop quickly or sit at a traffic light. This would allow more of the brake pad to “melt” to the brake rotor and the next time you pressed on the brake pedal the extra “glue” could be felt in the brake pedal or steering wheel.
The new brake pad formulations also caused another issue on any vehicle larger than a midsize suv. The force needed to stop the larger vehicle would now overheat the brake pad and cause it to perform poorly and stopping distance would increase dramatically. It would be like wetting the glue on the envelope too much and causing the glue to not stick. This made for a lot of brake issues that we had not seen before.
What happened at our shop and how we fixed it
I have to say our shop had been using the same brake pads for 10 years on every vehicle with zero problems. All of a sudden we were having all sorts of brake vibration issues and no one knew why. We switched manufactures and it helped on midsize SUVs but the trucks were another issue. We found that using factory brake pads fixed all the issues we were having. We sent back brake pads to the manufactures for them to study and that is when the found all the issues copper could fix with brake pads.
Fast forward to today January 2023 the issue is still there. The OE manufacturers are having issues now with their brake pads because they waited to remove the copper. The after market is getting close to solving the issue. This past fall we tried the old brand again because they came around and claimed to have the issue fixed. Well it is not.
So what can you do? If you drive a car or small SUV you probably will not have issues with ceramic brake pads. Any midsize SUV or truck you best bet is to get semi-metallic brake pads and avoid the vibration. Sometimes brake issues can not be avoided because the only brake pads available are ceramic. When that happens just know that you may have issues a few thousand miles from now and now you know why it happens.
If you want to go farther into depth about heavy metals in brake pads you can check out the information here.