Brake pads fall within the scope of regular maintenance items you have to replace periodically. For most drivers out there, it all comes down to choosing the right kind of pad for their car, getting the pads installed, and forgetting about the whole thing for at least 30,000 miles or until the rotors go bust. But, what if there’s a chance that you’re not getting the most out of your pads?
Many car owners out there have their brake pads’ life cut short without them even knowing it. Although not an inherently dangerous situation, you have to ask yourself, are your brake pads wearing unevenly causing you to spend more money than you need to on brake jobs? Join us as we explain why this happens and what you can do to prevent it in the future.
Why Are Your Brake Pads Wearing Unevenly?
Despite operating on a fairly simple idea of friction, your brakes are not that simple when you scratch the surface. A lot happens between the moment you press the brake pedal and your car slowing down.
If your brakes malfunction, one of the issues you could run into is uneven pad wear. Speaking of which, there are 4 main reasons why you might find that your pads are wearing out unevenly.
- Slider pin issues
- Caliper issues
- Disc thickness variation
- Caliper sticking
Each of these is enough to make quick work of brand-new pads and should be addressed as soon as possible. It’s also worth mentioning that each of these causes manifests itself differently on the pad. Knowing this, you should be able to diagnose what you’re dealing with simply by inspecting the pads.
Slider Pin Issues
Your average brake caliper consists of a caliper bracket that holds the brake pads in place and the caliper piston assembly that mounts on top of the bracket so that the piston is positioned behind the pad.
When you press the brake, the hydraulic pressure from the master cylinder activates the piston, which pushes against the inner pad. As it does so, the whole caliper piston assembly slides on two slider pins, which clamps the outer set of pads and keeps everything nice and tight.
For these pins to work properly, they have to be well lubricated. Additionally, the slider pin seals have to be intact as well, since they are the only thing keeping the contaminants and various debris from getting stuck inside the slider pin bore.
In an instance where slider pins are lacking lubrication and/or are unable to move freely, you’ll get uneven pad wear. Your inner pad will likely wear out faster than the outer pad, which can potentially cause all kinds of issues. If left unattended for long, you could be looking at brake rotor damage and more.
How to Properly Maintain Slider Pins?
Brake system maintenance goes beyond replacing pads and rotors, yet not many people, including mechanics, do anything more. The best way to prevent the issue of your brake pads wearing unevenly is to give your slider pins a quick refresh whenever you service your brakes. This means removing the pins from their bores, cleaning the old lubricants, checking the seals for any damage and replacing them as necessary, and lastly applying new grease before putting everything back together.
This is also a great time to inspect your anti-rattle clips and give them a good cleaning as well. Lastly, do yourself a favor and change your brake fluid every 2 years as that’s how long it takes for the fluid to become contaminated.
Caliper Issues
Calipers come in different shapes and sizes. The larger the caliper, the more pistons it is likely to have. Heavier, larger vehicles, or performance vehicles, tend to have more than one caliper piston inside their caliper assemblies. You’ll find 2, 4, 6, or even 8 pistons per caliper in some supercars.
Where things go sideways is when one of the pistons malfunctions. All caliper pistons ride against seals that protect the piston bore from debris as it moves in and out to press on the pads.
When those seals fail, debris will enter the cylinder and likely cause damage to the piston but also the cylinder itself. At that point, you’ll need to get a caliper rebuild kit or replace the caliper altogether.Any such damage can cause that particular piston to produce less pressure than the others.
An uneven force applied to the pad means that one side of the pad will usually wear out faster than the other.
Caliper Sticking
A sticking caliper is a fairly common form of caliper failure. When a caliper sticks, the pads are pressed against the rotor even when you’re not on the brakes. We’ve gone deep into why this happens in another piece, so we won’t go into detail. That being said, most of the time it’s the slider pins, caliper bracket bolts, or even the brake hose that is causing the problem.
A simple way to tell that your caliper is sticking is to check the suspected wheel for excessive heat. If one of the brake calipers is constantly clamping on the rotor, you’ll find that rotor to be extremely hot, to say the least.
Disc Thickness Variation
Disc thickness variation (DTV) is a fairly common issue that often causes a range of other brake-related problems. As far as your brake pads wearing unevenly, DTV causes this through lateral runoff. In other words, the affected rotor has a varying amount of lateral movement which makes the rotor wobble as it spins on the wheel hub. This creates flat spots that ultimately lead to uneven brake pad wear.
Rotors that are showing signs of DTV can sometimes be machined into shape, but in most cases, the best course of action would be to replace the rotor and pads altogether.
Can Improper Brake Pad Installation Cause Uneven Wear?
Although installing brake pads is a fairly simple procedure that leaves little room for error, it is entirely possible to mount brake pads in a way that leaves them misaligned. If that happens, one or both of the pads could be prevented from meeting the rotor surface at the correct angle, thus causing uneven pad wear.
How Soon Should You Address Uneven Brake Pad Wear?
The answer to this question is that it depends. Some of the causes are fairly benign and can wait for your next brake maintenance cycle, while others not so much. For example, a rotor suffering from DTV won’t last long.
Not only that, but it will eat up your pads in no time, meaning that you’ll have to do your brakes sooner rather than later. An imbalanced rotor can also induce vibrations in the steering wheel, especially if the amount of lateral runoff is moderate to severe.
With all that said, there’s a good rule of thumb when it comes to anything brake-related — get it fixed ASAP. Your brakes are the most important system in your car and can very well mean the difference between a safe commute and a potential tragedy waiting to happen. Service your brakes as soon as you notice that something is not right.
Quality Brakes Are the Only Way to Go!
Whether you’ve noticed your brake pads wearing unevenly, or you’re simply looking to refresh your braking system, it’s essential that you use quality parts.
Here at Newparts.com, we carry a wide range of genuine, OEM, and quality aftermarket parts for all kinds of vehicles, foreign and domestic. To find what you’re looking for, head over to our store section, select your vehicle using our car selection tool, and any search you do will only return parts that are a guaranteed fit.
