Hey guys, ChrisFix here, and today, I'm gonna show you the top five reasons why your brakes make noise. Now, this could be anything from a squeak, to a grind, and it could be continuous, or only when you press on the brakes, like this. (brake grinding noises) And since this Jag is making noise, it's a perfect time to show you not only the reasons why your brakes might make noise, but also how to fix it so it's nice and quiet. (brakes squealing) Because I don't know about you, but I hate when brakes squeak. Now this video is easily one of the most requested videos from you guys, So much so that I've been saving up all these brake components, from all the different brake jobs that I do, that way I can show you, the many reasons why brakes make noise. I also want to thank Advance Auto Parts for supporting this video and sending over a bunch of new brake parts. That way, I can compare the old brake parts to the new ones, and show you the difference. Now with that said, let's jump right into it, and begin. And the first thing we need to do is understand what brake noise is. And its pretty simple, its vibration coming from one of the brake components When you press on the brake, this caliper pushes the brake pads, and squeezes this brake rotor. That causes friction, and slows the car down. Let me show you an example on the rear brakes. So this is pretty cool, this is something you don't get to normally see, your brakes actually working So I'm going about 20 miles an hour (MPH) and then when I hit the brakes, you can see the brake caliper squeeze the brake pad against the brake rotor. Then when you let go of the brakes, the brakes pads move out very slightly so it just comes off the brake rotor, so the clearance here is really tight, this is less than a millimeter. And then this case you could see there is a bit of wobble in my brake rotor, and you can hear a light rhythmic scraping noise. And that's because this rear brake rotor is warped. Probably from all the track days and grabbing the e-brake for drifting. And since there a tight tolerances, there's a lot of pressure, there's a lot of friction, Even the smallest things could cause brake noise. And this noise could happen with brand new brakes, or with brakes that you've been using for a while. And not only am I going to cover the source of the noise for these five common problems, but i'm going to show you how to fix it, so your brakes are nice and quite. So lets begin with number one. The first and probably most important reason why your brakes make noise is because they're worn out. This could be worn out out brake pads, worn out brake rotors, or both. But let's cover brake pads first. Now this is a really worn down brake pad. Just to give you a comparison, here is a brand new brake pad, If we look here's what it should look like. You have the backing plate here, and then you have your braking material on top. and then if we look at the worn down brake pad, well, it's just a backing plate. This pad was worn down all the way to the rivets, and that's pretty bad. And on a brake pad like this, the only way that you know this brake pad is wearing down, is to take the wheels off and inspect 'em. But on quality brake pads, you have something called wear indicators. And wear indicators are these metal clips that stick out, past the backing plate. so as your brakes wear down to about two to three millimeters this will start screeching against the brake rotor and it will let you know that the brake pad is worn out. Now this brake pad is a perfect example of how wear indicators work. You can see the wear indicator is sticking out past the brake pad material So as you're driving along and you apply the brakes the wear indicator contacts the rotor surface and makes a squeaking noise. (indicator squealing on rotor) And that squeak will let you know that these brake pads are dangerously low and they need to be replaced before you get down to the backing plate, like this brake pad. So a wear indicator is definitely a good thing to look for when you're buying brake pads. So worn out brake pads can make noise, but so can worn out brake rotors. Every time you hit the brakes, the brake pad comes in contact with the rotor surface and the brake pad starts to wear down. And although the pads wear out a lot faster, the rotor also starts to loose material. And an extreme example of a brake rotor gettin' worn out is this right here. Now whoever drove this car wore it down to the cooling vanes, which is pretty bad. And I could only imagine the kind of noise that this brake rotor made when they pressed on the brakes. So when a rotor wears down, it wears down in the middle, at this smooth part. But it doesn't wear away the sides, which could create an edge over time. This edge could rust, and since it's so close to the pad, if the pad shifts at all it could make contact with the rust ridge, and cause brake noise. And if that's your problem, sometimes you can fix the noise with just a little bit of sand paper. All you have to do is sand the edge of the rotor where the rust is building up (blows on brake rotor) And then when you use your brakes, there is no more rust for the brake pad to contact so you won't get your brake noise. (blows on brake rotor) And to prevent your rotors from wearing out like that, there is a minimum thickness for every rotor. For example, this Jaguar rotor, brand new, is 24 millimeters thick. And then the minimum thickness, meaning you need to replace it if it' s thinner, is 22 millimeters. So all you have to do is, you measure it with a digital caliper. And this one is 23.4 millimeters thick, so we're within our minimum thickness. And when you are measuring, you want to make sure measuring down here on the flat surface and not up on the rust ridge. So if your brake rotors are too thin, you're going to have to replace 'em. In this case, if I wanted to I could get them resurfaced, but most of the time i'm replacing rotors anyway. By the time I get them resurfaced, it's a few more bucks just to buy brand new ones. Now worn out brakes are an obvious reason for brake noise. But these next examples are other common causes of brake noise that might not be as obvious. So the second common cause of brake noise could be seen right down here with my Jaguar and that is dirty or contaminated brake pads and rotors. Lookin' at these brake rotors you could see there is tons of grooves in here. These grooves are caused by dirt getting in between the pad and the rotor, and then when you press on the brake pads it digs into the rotor. That could be road salt. It could be dirt from going off-roading. Maybe you drove through a muddy puddle. Basically anything small enough to get in between the brake rotor and brake pad surface. The grooves could also be caused by poor quality brake pads which have bits of hard brake material scattered in them which could score the rotor surface, especially when the rotor heats up. Another type of contamination that can make your brakes squeak are rusty rotors. Depending on where you live, rust could be an issue and brake rotors rust really easily. Check this out - I sprayed a rotor with water and in a mater of minutes; you can actually see the water droplets evaporating and rust forming on the rotor Now a little rust like this isn't a problem at all. But if you let your car sit for a long time without driving it the rust could be bad enough, like with this rotor, that you need to get the rotor turned or get a new one. So that's contamination on the rotor surface. But how about the brake pad surface? So before you go out and buy brand new brake pads; because sometimes your brake pads have a lot of life left on them. One thing that you can do is you should grab some sandpaper - in this case I have 180 grit but anything from 100 to 200 grit will work - and just sand down the surface to remove the contaminants. (sanding noises) So that's how you remove the top layer of contamination; but in this case our pad is so grooved that it's no good. Same thing with our rotor - that's grooved so we need to replace that. And that brings me to my next source of contamination. And that's brand new brake rotors. To prevent your brand new brake rotors from getting rusty in the packaging; manufacturers use an oil coating which needs to be removed. To remove this contamination, you could use brake cleaner, or you could use plain old Soapy Wooder. All this is, is dish soap and water. I prefer using brake cleaner when cleaning the rotors; so just spray it on there, then wipe it down with a clean towel. Now check out all the oil we removed - you definitely don't want that on your brakes. And you don't want to forget to clean the other side as well. GOOD! And since we're talking about cleaning with brake cleaner - one thing I want to talk about is getting brake clean on your pads surface. So can brake cleaner damage the brake pad surface if you get it on there? The answer to that is YES. You don't want to use brake cleaner on your brake pad surface. It could break down the material of the brake pad. It could cause swelling. The other thing is - a lot of brake pads are painted. And brake cleaner damages the painted surface, which could cause rusting. And then some brake pads use this rubber backing plate, and the brake cleaner could eat away at the rubber backing plate. Now that being said - if you get a little bit of brake cleaner on there, it's not the end of the world. You just don't want to soak this and saturate it in brake cleaner. So if you do get some brake cleaner on here or if you get some oils on here one thing that you can use is just plain old dish soap and water - spray it down and wipe it off. So brake pad and rotor contamination is the second reason brakes make noise. And lookin' at these brakes, they definitely have to be replaced - both pads and rotors. And I just noticed something - that there is no brake hardware. Which brings me to my next reason on why your brakes might make noise. So the third reason - and probably one of the most overlooked parts to changing out your brakes - is replacing the brake hardware. Brake hardware are any of these components that are in or around the brake caliper and brake pads. For example we have a brake caliper here - and here is our brake hardware. And it just clicks (audible click) right in like that. And what the brake hardware does is it allows the brake pad to slide smoothly and quetly in the brake caliper. And as your brake pads wear out, your brake hardware wears out. And it becomes difficult for your brakes to slide smoothly in the brake hardware. And that friction could create squeaks and also could create excessive brake wear. And that's for disc brakes. But there's also brake hardware for drum brakes. Drum brake hardware is made up of springs - which are very important - and let me show you why. I cut apart this drum so that you could see how everything works. When you press on the brakes the wheel cylinder pushes the shoes outwards. Which then rubs against the drum creating friction and slowing the vehicle down. When you let go of the brakes, the springs pull the shoes off the drum so there's no more friction. And there isn't too much space between the shoes and the drum, so the springs have to be in good shape and working properly to ensure that the shoes don't continue to rub against the drum with your foot off the brake. So you could really see the importance of getting new brake hardware. Which is why when you get new brakes - make sure it comes with brake hardware. And if it doesn't, it inexpensive enough and worth every penny. Now with that being said, some cars don't use the typical brake hardware. For example - on my Jag, when you get new brake pads, the only brake hardware they make for this car are the guide pin bolts. So for brakes like this, all you have to do is get a metal wire brush, and where your brake pads make contact with the caliper you want to clean out this area real well so it's rust free and nice and smooth. If you have a rotary tool - you could get a wire brush attachment and it makes cleaning this up even faster. And all you're trying to do is get the surface smooth and rust free so the brake pads could slide freely - just like that. So not using brake hardware is the third reason why your brakes make noise. And since I need new rotors, I want to share a top tip with you. Anytime you replace rotors - make sure you use a wire brush to smooth down the hub surface so it's not rusty and rough. Rust could cause the rotor to sit unevenly and cause brake rotor runout which could look like a warped rotor and give you a rhythmic braking noise like this:
(engine noise - rhythmic rubbing sound) And you also could feel this, because the brakes might pulsate. So get that hub surface nice and smooth, and then apply a thin layer of anti-seize to prevent future rust and make it easier to get the brake rotor off for your next brake job. Speaking of anti-seize - the fourth reason why your brakes make noise is because they're not lubricated. So we're going to be using two different lubricants to lubricate two different things. We're going to be using the Copper Anti-Seize to lubricate any contact points between the brake pads and brake caliper. And then we're going to use the silicone paste to grease the caliper guide pins which definitely need lubrication. These things are stiff. So first - let's talk about the anti-seize lubricant. Now whenever I replace brakes I like using copper anti-seize compared to graphite anti-seize. They both will work, but copper anti-seize is better for brakes. And here's why - every time you press on the brakes, the braking system is under a lot of pressure. So to simulate graphite under a lot of pressure I have graphite from a pencil. And what I am going to do is i'm just going to put pressure on it - and it's not even that much pressure - and you can see what happens - the graphite breaks down into smaller pieces. Now that's good if you're trying to lubricate the threads on a bolt, and it will work for the brakes, but it's not as good as the copper anti-seize. To simulate the copper anti-seize under pressure - I have a thin copper pipe. (hammer blows to copper pipe) And if you take a look - the copper just bent. It didn't break up into little pieces because copper is malleable compared to graphite, which isn't. So copper based anti-seize holds up better under pressure while graphite based anti-seize continues to break down. Which is why, if you can, you want to use the copper based anti-seize when lubricating your brakes. So to show you how to properly lubricate disc brakes, we're going to use my mustang as an example.
