How to Bed-in / Burnish Brake Pads and Rotors

so when we get new parts for our car we've come to accept that you have to break them in first get some new race tires you take them out in the heat cycle them you buy a new engine you go through your break-in procedure well unfortunately with breaks somewhere along the way it became okay just to get some new pads and rotors throw them in and go out and Hammer them on the racetrack without preparing them properly that's a really bad idea and there are a whole bunch of reasons why in this episode of no brakes we're going to tell you why we're going to tell you how to bed in your pads and rotors properly get them ready for heavy use so you can get more enjoyment on your car are you mad about so what is betting and brakes well there's also another word for it it's called burnishing so we'll use those interchangeably throughout this video in racing the word Furnishings a little more popular whereas in the aftermarket most people use the term bed-in but basically what you're trying to do is made up your pads and rotors get them to the point where they're ready for heavy use so there's really two ways your pads typically operate whenever they're applied to the brake disk one is an abrasive manner that's basically where the pad is rubbing on the rotor face and generating friction to slow you down the other is called the inherent mechanism which is the pad material is actually transferred onto the face of the rotor and then the pad rides on that thin layer of pad material that you've put on the rotor and that's really what we're going to talk about in this episode is how to get that pad transfer layer onto the rotor properly how to maintain it and all the benefits you'll get from doing so so the first obvious question is if I just put in my pads and rotors and I go out and I drive them around and I take them to the racetrack or on the street what am I missing out on well you're missing out on a whole bunch of things first of all you're missing out on some white or higher friction level that you would have if you put down a transfer layer on the rotors you can think of this like a drag racer he goes out he does his burnout and what's he trying to do trying to lay down rubber on the track so he has more grip when he launches his car the like materials on the track the rubber on the track and the rubber on the tires they have a higher friction together than if he was trying to launch off of the track itself it's the same thing here when you lay down that transfer layer on the rotors you're going to have more grip with your pad than you would if you were trying to grab the bare iron face so that's the first thing the second thing is noise a lot of people complain about noise you know I'm getting the squealing whenever I apply the brakes well a big part of that is if you put down a transfer there you're going to get rid of a lot of that noise so that's another big one another benefit is you're going to have an even transfer layer on there if you do it in a controlled manner if you go out on the track and you heat your pads up and you take them over their temperature threshold and you don't do it in a controlled manner chances are you're going to get uneven pad deposits on your rotor so basically the pad heats up it splotches on the rotor face and you get high points around the rotor and what that's going to do is every time the rotor spins around to that point where your brake pads are clutching the rotor it's going to give you a vibration or a thumping and you're going to feel that when you go into a turn either through the brake pedal or through the steering wheel it's really distracting when you're trying to go into a turn and you have that thump-thump-thump so that's another big benefit of betting in the pads and putting down and transfer layer in a controlled manner on the other side with the disc itself you want to gradually heat that iron rotor up over time you don't want to go out and just thrash it at a high temperature because what you're doing is putting a lot of stress on the metal so when you do your bed and you're going to gradually heat that rotor up over time in a very controlled manner so it's going to really help with preventing cracking and as we all know crack rotors cost money and we don't want to do that if we can avoid it so you're probably asking yourself how important is betting in my brakes or burnishing them well if you talk to any professional race team you're going to find out that not only are they burnishing or betting in their pads and rotors sometimes they're doing it all the time and in most cases they're actually paying us or someone else to do it for them because they want it done in a very controlled environment like our dyno so they're there looking at it as this is so important that we want it done as well as possible to give us that little extra performance edge so it's extremely important along those lines I brought in an expert on this topic to talk about the race side of things and how important this topic is to them this is Steve hood from AP racing he's been an engineer with them for about thirty plus years and he's been around every type of racing and he really understands this topic and knows how important it is to the themes so Steve what are we trying to accomplish when we bed in disks on our diner burnish is an extremely important part of the Break process what we try and achieve when we furnish your disc is to introduce the heat on a controlled basis into the disc itself one of the issues when you try and do that yourself at a track or a test day is it's not a controlled environment you can tell the driver exactly what to do but the chances are he's not going to follow every step that you're telling to go it through so we use a an established process and that we've developed over a length of period of time where we've looked at different materials different pad compounds different discs the weight and the usage of the disc is extremely important in determining how we bed the disc itself so how does the bedding procedure differ by team generally it will depend upon the disc whether it's a road course short track intermediate Superspeedway disc and the pad compound there is quite a difference whether you're betting a 15 a in f2 or a PFC o1 the compound itself has reacts very differently the way the compound actually works the weight trunk puts a transfer layer down onto the disc itself so we kind of vary the bedding procedure dependent upon the disc in the pad the team went out on the track before preparing their brakes properly what would they be missing out on in terms of performance I think you lose two things first of all you're going to lose tracked on particularly if it's some at a practice session where you can't really afford to waste time having slow old build up laps for the driver to to get the brakes to come in he needs to be needs better go out on the track and have maximum performance from lap one the other problem is that you you can't guarantee that you're going to put the heat into it in a controlled fashion so certainly you can if you put too much heat in too quickly even with a high quality race disk you can you can run the risk of either crack in the disc or distort the disc so it has to be done on a controlled basis over a period of time so Steve or any of the bigger teams skipping this preparation step before they take the racecars out on the track no you know just about it certainly and the higher ranks of motorsport in this country the coke bush and truck series that they nobody goes up with an unfurnished disc everybody burnished these discs before they go out thanks a lot for your time Steve really appreciate you sharing your insights on this topic thank you now we're going to take a look at the burnishing machine in action I wanted to show you how this procedure works in a controlled environment and this is the ultimate of what we're trying to accomplish when we do this procedure out on the road we want a nice even layer of Pat material laid down all the way across the rotor finish from top to bottom and you'll see it build here I sped this up because you don't want to sit here and watch the entire procedure you fall asleep but it's a series of stops with a set pressure from certain speeds that we do it varies depending on the type of finish you want to achieve but I just ran a basic one just to show you finished rotor from the controlled burnished versus a raw rotor and I line them up here at the end so you can really see the nice blue gray color versus the raw untouched brand-new silver rotor and again this is what we're trying to achieve when we go out and do the procedure on the road so an obvious question is where am I going to do this bed end procedure I live in the city you know there's people all over the place there's really no we're good to do it well that could be tough ideally you do it on a race track in a controlled environment where there's no obstacles there are no kids running to the street or animals you have to be really careful about this so you want to be selective about where you do your procedure if you can't do it on a race track it's okay to do it on the street but you got to make sure you obey the local laws you know we essex in no way encourage you to break the speed limits or do anything illegal so you should find a road if you're going to do it on the street that has a high speed limit long straightaways where you have a good field of view and you know no obstacles you don't want other other cars out there if at all possible so you'll see in this video we're using a country road we went and did it at dawn unfortunately it washes out some of the video but the reality is we want to be safe so you want to do it at a time when there's this little traffic as possible as few obstacles as possible another option would be if you live in a city when I lived in LA I used to go out in the industrial complexes and do it at night when everyone was home there's no one around and be careful you know the police do patrol those areas but that was a pretty safe environment where there wasn't a lot of stuff around to interfere so and then I would go do my cool down on the highway after I was done you know just go hit the freeway drive and cool it down so just some suggestions on where you can do this procedure to be safe so let's talk a little bit about the actual bed-in procedure so it's going to vary a little bit depending on the type of pad you are using like I was saying before with the dyno if we have a very mild street pad it's going to require a different procedure than if we have a very high temperature race pad so let's talk about street pads you get your aftermarket street pad or even your OE street pads and how do you get that transfer layer onto the rotors basically you want to gradually bring them up to temperature typically from a speed of about 60 miles per hour and you're going to break down to about 5 miles per hour now why 5 miles per hour you don't want to come to a complete stop if you come to a complete stop while the pads are hot they're going to imprint in one place on the rotor and you can actually see if this is done you will see the outline of the pad on the face of the rotor so you want to avoid coming to a complete stop so the procedure you go out go up to about 60 miles per hour and it doesn't have to be 60 exactly you know watch what you're doing you understand that's a speedometer you just want to get enough speed where you can generate some heat in your stop break down to about five miles per hour and then you're going to immediately go back up to 60 miles per hour so you don't want to let the brakes cool off you want to keep the heat building in the system so one after another 62 five 62 five and you're going to do that anywhere from eight to ten times again it's going to depend on the compound so you know you have to be careful a lot of manufacturers recommend one type of procedure or some recommend another you're just going to have to find out for the specific pad you're using what the proper number of stops is going to be so we're going to go out on the road and do that and I'm going to show you from inside the car how that works I took some shots from outside of the car honestly they're not that exciting so I wanted to show you real time in the car how the procedure works so you can get a good feel for how to do it on your own okay now I'm going to start my series of stops as I outlined up to roughly 60 miles per hour and then down to about five or ten and then immediately back up to sixty and just repeat you don't want a BS intervention under stop so you want a threshold break hold your pedal just before a BS intervention you'll get the hang of that the more you do it you know you'll hear some tire squeal and you'll get right to that point before abs and then just hold it there nice and steady you'll see in this case even on the second stop we're already seeing a little smoke that's some of the resins burning on the pad as you keep them up so no need to panic there that's completely normal that's actually one of the biggest mistakes people make they don't give the pads hot enough to actually transfer material onto the rotor face and then you'll see here in two stops four and five you'll start to see some sparks at the interface between the pad and the rotor obviously you won't see it if you're driving the car but you can see it in my video at this stage the pads are starting to get more bite as they heat up and start to transfer onto the rotors you'll feel that through the pedal pedal and feel more grabby you can feel that bite and then as you look at the rotors you'll see that they're starting to change color a bit they're going from silver to more of a blue gray color as the pad actually transfers onto the rotor and then as you get up into stop seven eight nine the smokes will get a little thicker as the pad eats up more and you may get to the point where you start to fade about at that stage the pedals still going to feel firm but the car is not going to be slowing down as you would expect it to so once you start getting some serious path fade there it's time to back off and you just want to go for a drive cruise along if possible don't stop the bit the one that you don't want to do is come to a complete stop with your foot on the brake that is the biggest nono here so cool everything down drive around get some airflow over the rotors and pads and then we'll take a look see what we have now we're going to take a look at the results from the first bed in cycle a quick note before we start though the rotors and pads when we're both brand new I just want to make sure that's clear for the start of this cycle they were on the car the car was washed and sat for a day or two that's why you see the rust down near the Hat the rotors were just from my local auto parts store and the pads were a very basic popular aftermarket street pad if you take a look at the rotor as new here you can see the cross-hatching on the rotor face they're a silvery color there's no pad material on the face of the rotor and then you can see here after the pads go through the first bed-in cycle down the other the hat you see a blue ring from the heat and you also see a blue gray color across the face of the rotor that I pointed out during the cycle that's the pad material as it was lay down so in this case I looked at it and thought well the transfer layer isn't very thick I can still see some silver shining through there I think I'm going to run them through another bed in cycle to make sure I get enough Pat material laid down on there so that's why we went back out let's do another cycle and then we'll pull the rotors off the car and really get a good look at them after that okay now we're going to go back out for our second series of stops and you'll notice that even though I drove the pads around for about five minutes to cool them down there's still a lot of residual heat in the system so they aren't back down at the ambient temperature and that's why you're going to see here or even on the early stops in the series we're getting Sparks and smoke and the Pats don't take as long to get up to a temperature where they're going to transfer onto the rotor so here at my stops number two and three I'm already transferring material over to onto the rotors whereas in the first series it took four or five stops in this case I'm able to start to fade the pads and stops six or seven maybe even on five and you can feel that through the pedal in this case I decided to continue on and push through because I wanted to show a few different things one I wanted to show how easy it is to overheat a set of street pads to be comparable going out on a canyon run if you have a mild set of street pads in there it's very easy to push them to the point where they're lighting on fire and fading on you pretty badly so you got to make sure you have the right equipment in there also I wanted to show that if you do this properly and you lay down a nice even layer over over a period of time you don't have to worry about trashing your rotor as much if you do in control man or you can get to the point where you light them on fire and smoke them up and your rotors gonna come out okay you don't have to worry about ruining them whereas if you do it in an uneven manner and accidentally you can trash your rotors pretty badly so a couple different things I wanted to show in this series but you'll see here on my stop number ten I push through and I lit him on fire I could feel that through the pedal and I went into my cool down there because I could just tell that okay they've pretty much given up a ghostie passer are done they're passed their temperature so it's time to cool them down we went back out and did our second series of stops and you can see here through this progression the difference in the rotor face the first one again shows the rotor as new and then we'll look at it after the first band in cycle and then we see it in the after the second bed in cycle and it's very obvious that the pad layer as much thicker on the rotor they don't they don't have any silver color anymore they're blue gray darker color thicker pad layer has been laid down and what we're going to do next is show you some shots of the pads and rotors both before and after off of the car so you can get a really good look at them in a controlled lighting environment and see the differences so this ought to help you understand what you're looking at and what you're trying to achieve when you do it on your car again it's even more obvious in these shots the differences in the rotor face I did it from a number of angles to give you an idea you can see the grinding marks during rotor manufacturer versus what the rotors look like after a Bedan cycle and also took some shots of a pad you'll notice the paddle particularly on the edges you can see they're singed a bit the paint on the edges of the pad puck itself always burn and curl back usually there's a white or brownish edge and it looks like ash typically all along the edge of the pad so that doesn't mean you killed your pads or you run them or anything that just means that you got them up to a high temperature and burn them kind of scorch them a little bit so those are what the parts will look like after you're done if you've done it properly okay so you got a good look at me doing a bed in on some basic street pads you know these are standard aftermarket pads nothing too fancy the difference is when you go to a race pad everything changes a bit with a race pad it's designed to operate at a higher temperature so it's not going to be as easy to get that transfer layer generated on the rotor face so what you need to do is go to a higher speed now like we showed you earlier we can control a lot of factors on the dyno so if we wanted to get more temperature out of it we can add more pressure or change the length of stops or all sorts of variables we can control out on the road you're going to only have a limited number of things you can do one is if you're already immediately starting your next stop there's not much you can do to control the length of time between those you know the other thing is you can't control pressure at all your calipers or your brake system is going to be putting out a constant pressure that it's capable of so what do you have to do you have to adjust your speed now this is where it gets a bit dicey you definitely don't want to try to do this on the street with a race pad because you're going to have to hit higher speeds with most race pads you're looking at 80 plus miles per hour to get the the energy into them to really start generating a transfer layer in some cases a hundred works well you go up to 100 miles an hour it may not take as many stops as ten but from the higher speed it's a higher energy stop so you go out it's the same procedure you just need to put more energy in the system to get those pads up to a temperature where they're going to start transferring so higher speeds typically on most front engine cars like most of us drive the front brakes are doing a lot more work so your rear rotors are going to need a little more work to get heat into them to start transferring over so you may not see as heavy of a transfer layer on the rear rotors as you would on the front and that's going to again differ by car type there are some other important factors you have to think about - one is big break kits or ducting if you have ducting you really want to block those off before you do a bed in cycle because what they're doing is constantly fighting you you're going to go out you're going to try to bed in your pads and generate heat at the same time your ducts are going to be drawing in cool air bringing them into your brake system and cooling it down so you know if you have ducts on the front of your car I'd say just put some painters tape over and cover them up so you can get more heat built up in the system quickly that'll make it a little easier to for you to develop a transfer layer the other thing is if you have a big brake kit on your car it's going to be harder for you to do a bed end than it is if you're running the stock equipment you know you have bigger rotors which are a bigger heat sink the calipers larger holds a bigger pad with more volume so all the reasons you bought that brake kit are going to make it harder to do a bet in than if you had the stock equipment on there so keep that in mind what may work for someone with a stock brake system on a certain vehicle isn't going to work so well if you have a big brake kit so you may have to do more stops to get that temperature build up or from a higher speed so just another point to keep in mind all right so you've done your bed in cycle and you have this great transfer layer on there the brakes are working fine everything's good and you drive that car around on the street for a couple weeks and you look down and well there's no transfer layer in there anymore or you start hearing some squealing from your brakes and you say what's that and you go check it out and your transfer layer is gone well that's going to happen over time when your pads are operating in their abrasive manner it's going to wear that transfer layer off of the rotors so this is something you're going to have to maintain if you want the most performance out of it you're going to have to go do this bed in cycle on a regular basis it's going to depend on how often you drive the car or how you drive it whether you're driving the brakes hot or cold all those variables are going to come into play but it will happen eventually that transfer layer will come off if you're driving this thing around cold so that's something else to keep in mind and you know you see a lot of people say hey I did bed-in and the noise went away but you know two weeks later I have the noise back what's going on well that's chances are that's probably what's happening with your system so keep that in mind this is something you're going to have to do on a regular basis if you want to get the peak performance out of your brake system so hopefully you now have a better understanding of why we bet in our brakes how to do it and the benefits you're going to get from it I think you're going to find that your brake system is going to give you a lot more performance than it had previously if you weren't doing these procedures you're going to have more by better pedal feel easier to modulate less noise you're also going to have less cracking in your rotors it's going to save you a lot of money and I think you're just going to enjoy the car more so be safe have fun and hopefully this helps you out a bit you

Channel: Essex Parts Services : Brake Experts

Views: 100,163

Rating: 4.8294415 out of 5

Keywords: brakes, brake pads, brake discs, burnishing, bed-in, ap racing, brake rotors

Id: pdPX6rzuINc

Length: 25min 41sec (1541 seconds)

Published: Mon Jul 06 2015