Yes, I did do a quick search. Yes, it has been explained to me before. No, I still don't understand the reasons why. So why is it you need to bed brake pads? What if I don't have a chance to bed before I get on the race track? Anything I can do in the pits or does it help to work on bedding them the first couple laps and then you can go for it? Or is it a must that they cool after bedding? Do you still bed street pads on street cars? Thanks, rob
The reason racers bed their pads in is to allow brake material to transfer to the rotor and off-gas material from the manufacturing process. Doing so allows the pad to reach its maximum performance quicker. I have also heard that it can extend the life of the pad but I really don't understand the reasons behind this. On the street, it is not important to bed pads in as you really don't need to reach max braking performance for a trip to the supermarket. Instead, during the course of normal driving the pads will eventually transfer material to the rotor and braking performance will improve. You just need to be careful and aware that you don't have full braking capabilities right after a pad change. Racers bed their pads in because they want max performance on Lap 1. They do not want to wait for the process to happen naturally. I have bed my pads on the track before in a pinch, but its not the best solution. Try a google search on Pagid's bed in procedure and you'll see why. That said, if you don't have the time to find a safe place to do it on the street, bedding them in on your first lap isn't that big a sin. As an aside, also remember its not a good idea to change pads and rotors at the same time.
I think bedding is important for ALL pads, whether street or track. Check out Dave Zeckhausen's terrific write-up at http://www.zeckhausen.com/bedding_in_brakes.htm for some detailed information. (And Rob, isn't it fun to slam on the brakes just to get a whiff of those fresh pads? "Mmmmm, tastes like burning")
Rob, The main reason for bedding is to evaporate the last of the volatile components of the brake pad material-----all the binders and other goop which hold the friction material together.If you don't, a layer of vapor forms between the pad and rotor resulting in "green fade". = "NO BRAKES !!!!!!!" I know what you're saying about not wanting to bed brakes on the track. If you do it in practice you have to be VERY CAREFUL as you might get rear-ended. You don't want to do it during the race as you would probably like to have brakes for Turn 1. So what to do ? ------Pre-bed them. I've been doing it for over 20 years of racing and it has always worked like a charm. Get an old toaster oven and place it anywhere but in the house. This is one of the worst smells on Earth. Set for 400 deg. F and "cook" the pads for 4+ hours. Let cool and your done. Hope this helps. Good luck.
Tom, I've read (and tried) several quick bedding methods which generally involve taking the car out on the road, getting up to speed, braking, speed up, brake, etc. They work quite effectively, but require driving the car for at least 1/2 hour and then letting the brakes cool down. Never heard of "cooking" the brake pads to bed them. Great idea! Interestingly, I just read an article about "Green Stuff" performance pads, that they are now delivered with a special coating to promote rapid bedding and to avoid loss of brakes due to fade during the bed in. Regards, Steve W.
While we track junkies like to preach that pads should always be bed in and I bed my own street pads in, the evidence of millions upon millions of drivers not bedding in their street pads seems to indicate its not a big deal. Manufacturers don't even bother to recommend it for street pads because they know it won't be followed nor do they bother to pre-bed them before they leave the factory because the performance gains on the street do not merit the time and expense. I have to go with the overubundance of real world evidence on this one. When bedding them in on the track, this is something I have only done on member days at MSR when the track is fairly empty and safe. As someone mentioned, you don' want to get rear ended nor do you want to create a road block while you are driving slow to allow the brakes to cool before your next threshhold brake.
Some bedding recommendations I've seen are pretty complicated. I like Pagids... 35 mph for half mile holding brakes a little. Drive another mile without brakes to cool. Stop normally from 35 mph. Done! I can do that easily in the pits. --- Their site also talks about you need a "coal" on the surface of the pads, which can only happen at 550 degrees. They don't really talk about the gasses or chemicals much, but that might be another way of saying it. In the RX7 I've seen my pads get a glass like finish to the the surface, but that's probably glazing my pads by overheating vs. a "coal"?
I just read the Zeckhausen procedure, and it's about the same as others I've used. Works well. The one thing they don't say though is that when you get done doing this, you should NOT set the parking brake. For that matter, when you come off the track, you should not set the parking brake. Rotors and brakes are very hot, and setting the parking brake can lead to warping of the rotors. Regards, Steve W.
Steve, I believe in keeping it as simple as possible. The traditional method is all well and good until you weren't able to bed your pads in practice / qualifying due to some mechanical malfunction. My method assures that you will be able to slow down for Turn 1. We're not talking "track days" here but a real , SCCA National Race. Not much time for anything and full of unforeseen mechanical issues. That's why I always tried to prepare as much as possible.
Bedding pads (put simply) is a neccessary method of removing the transfered/residual materials left from the old pads off the rotors, and applying a new (and hopefully uniform) layer of material from the new pads onto the existing rotors - you'll avoid annoying brake shudder if you sufficently bed the pads - to accomplish this, you need to get sufficent heat into the pads before use. This is my bed - in procedure: 5-8 stops from 50 - 30 with even, moderate pedal pressure 5-8 stops from 65 - 30 with even, moderate pedal pressure 5-8 from 55 (or 65) to zero with strong, but even pedal pressure (You should be near threshold braking on these last stops -- the pads should really "come on" by now, and you should smell them.) After that cycle, stop, let the brakes cool, then repeat. If you need to bed them in on track, then do the following: 1st lap go easy, and work heat into the brakes moderatly by not using a lot of pedal pressure 2nd lap go a little faster, go firmer on the pedal pressure, but remember to do it progressivly 3-4 lap, same as 2nd lap then once you get the pads hot and smelly, take a cool down lap trying to stay off the brakes the entire lap, pit and let 'em sit for a while. Remember, you don't want to be anywhere near race speeds for the above procedure - use caution.
Rob, good seeing you last weekend! Here is what I do with full track pads. It works GREAT: 6 cycles with GENTLE braking from 50-35, to get everything warm GENTLY. 6 cycles with FIRM braking (no ABS if you have it) from 60-10. 8 cycles with VERY FIRM braking (no ABS or lockup) from 80-10. Drive around with NO braking for 10 minutes. Let the car sit for 2 hours or so. Presto!
Good seeing you. I hope your M3 works out. I had a great time instructing, I think I'll start doing that more often. Just driving myself around has gotten boring, so watching the excitement and improvement of the students is refreshing.
All of the above procedures will work just fine, though am surprised at the Pagid 35 mph stuff. When in doubt, contact the manufacturer. 15 years ago I too was baking pads 'cause the manufacturer said to do it. Though they said do it with an acetylene torch. (I don't recommend this.) Performance Friction offers a bedding service, and most pro teams use it (track time is big bucks for a pro team). It's just a rotor and caliper attached to a 500 hp V8 engine. Cool, huh? Best regards, Rob Schermerhorn BTW, I recall a Corvette Challenge team bedding pads late at night in Road Atlanta's paddock 15 years ago. Easy to see the rotor's glow, which meant at least 900 degF at no more than 25 mph.
Can someone tell me why? BTW, here's the response I got from Porterfield regarding bedding in the pads (street and track use may differ). Henry, Just install and drive normally for the first two days or 100miles they will bed themselves in. After that you can drive harder on them. Just try to avoid stops from 60-0mph some people do this to see how good they work but this can thermal shock the pads and then they will squeak and it will take several miles to get the glaze off. Thank you, Wendy
Funny you should dig this up. I've been having some problems with "wobble" on my daily driver after just having the brakes done about six months ago. I took it back and without even looking at it they proclaimed that I would need new rotors because mine were now warped. After a little research I found some interesting info including this article from Stoptech (which seems to have been partially quoted above by the way)... http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml I've heard this issue debated before and couldn't decide what to do when I did get the new pads. The shop that did the work said just drive it normal with no hard stops for the first few hundred miles. After doing this they developed a squeek so I tried the method mentioned above and in the article I linked. Now they don't squeek anymore but I am experiencing the "warped" rotor. I found some garnet cloth and am going to try "cleaning" the rotor and find out if this solves the problem. We'll see but my experience seems to point to following the procedure above for performance oriented pads for bed-in. Sorry for the ramble but hope the info helps! Edit: It would be interesting to hear Martin or one of the other brake experts weigh in here!
If you are getting a pedal pulsation it is likely from warped rotors. If the offending rotors are within spec (still have sufficient remaining thickness) they can be machined for around $15 each like the Diablo rotors shown here. If it's one of your Fords, new rotors aren't a big expense. New ones for the Lambo are $1702.45 each from the dealer! Image Unavailable, Please Login
This seems logical, but then why did the previous quote say not to do pads and rotors at the same time?
Maybe we're just lucky here in Oz... but for about US$60 extra, I can buy any pad I like pre-bedded on a brake dyno... I do it for all the race cars, as rexcr commented... track time is better used for other things in a race team.
At a very brake intensive track, if you don't properly bed-in the brakes then this is what can happen. New rotors & pads are toast after 1 or 2 sessions. There won't be the proper transfer layer on the rotors, So the pads & rotors overheat, gets glazed. You have to apply more pressure. It's gets worse and worse and pretty soon the rotors become so scored and cracked it's not safe to stay on track. We have learned our lesson and now we never bed in new rotors & pads at the same time. Prior to race weekend, we use old pads to bed-in new rotors in 1 session, then after that, put new pads on the just beded-in rotors to bed-in and cook the pads in a second session. Very time consuming, but we don't have any brake dyno bed-in service where we are. For less demanding tracks, then for the 1st session just run 2-3 laps at 70% to bed-in, thereafter do 1 cool down lap for every 2 hot laps seems to do the trick OK. Image Unavailable, Please Login
Not to make this confusing, but.... I took the race pads off my car (terribly noisy for the street) and put porterfield street pads on. Can i put the race pads back on for track use without repbedding? Or will this ruin my rotors?
You better check with your race pad manufacturer to be sure. For us, we would do a couple of warm up laps even when we switch compounds from the same manufacturer. Bottom line seems to be if the track is very demanding brake wise, then every single little detail seems to be important. At more flowing tracks where you're not always stomping on the brakes from top speed, then nothing seems to ever go wrong even when you don't really watch the bed-in procedures.
That's why I linked the article from Stoptech. According to them there almost never really is a warped rotor but more likely irregular transfer of pad material(or in rare cases a crack). I'm guessing that the improper bed-in I did per the shop's instructions led to this condition. My problem is on my Lincoln LS and, yes, there are very cheap rotors out there. I figured if I'm going to replace them though I might as well step up to slotted at least. With only 40K miles on the car it appears there isn't enough left to turn them once more (although I haven't checked that myself). My post was intended to be directed more towards finding out why it appears the proper bed-in procedure isn't explained to folks better. I suppose most shops are dealing with people who drive thier cars in very normal conditions. Liability could be another explanation.
