Doing a brake job tomorrow need advice

"Nisman" (nisman) 03/21/2015 at 23:21 • Filed to: None

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Sorry for formatting thanks iPotato. so I'm replacing front rotors tomorrow with AC Delco rotors off amazon (02 maxima) and I'm going to use the existing pads. I replaced them just over a year ago. I had the old rotors resurfaced but they keep warping. Is there any risk to damaging the new rotor with the old pads? What should I watch out for? They were decent pads. Paid $40 for them from Napa. They are a ceramic pad. I'm just nervous because I've never just replaced rotors without pads too. Thanks!

mattc993 > Nisman 03/21/2015 at 23:27

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Read dis:

http://oppositelock.jalopnik.com/brake-myths-wh…

Lots of great stuff to learn in there (including the fact that rotors don't actually warp - that's a headlight fluid/canuter valve misconception).

AMGtech - now with more recalls! > mattc993 03/21/2015 at 23:37

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Saying brake rotors don't warp is just arguing semantics. 99% of people will state at you blankly if you say their rotors have excessive thickness variation or runout. You say they're warped and people understand.

whoarder is tellurium > Nisman 03/21/2015 at 23:40

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Ideally you'll want new brake pads too. If its possible, just do it.

cbell04 > Nisman 03/21/2015 at 23:42

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I've owned many maxima's a great car to learn brakes on. nothing will be to tough. Be prepared to beat on the old rotor to get it to pop off. I would get the pads personally they are cheap enough but cant say I haven't went the route your going once before.

mattc993 > AMGtech - now with more recalls! 03/21/2015 at 23:42

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I mean I totally get that, but this is oppo. Most of us are willing to go the extra mile.

I'd think Nisman would appreciate it if I didn't think of him like "most car drivers" (that wouldn't understand/care what makes a rotor *feel* like it's warped).

Buick Mackane > Nisman 03/21/2015 at 23:43

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I also would like to know if you can re-use a slightly used set of brake pads with new rotors. Also, does anyone ever prep their brake pads by taking a Dremel tool or something similar and grinding off a small amount (1/16" inch) from the perimeter of the brake pad surface before installing?

cbell04 > cbell04 03/21/2015 at 23:47

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oh and there are a couple video s on the youtube for step by step instructions. All models have basically been the same so dont get hung up on the year. Newest one I owned was a 2000 but it was the same process as the 95 and the 92 so assuming the 02 will be the same too.

Chuck 2(O=[][]=O)2 > Nisman 03/22/2015 at 00:01

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I would spend the $30 and get pads with everything

Big Bubba Ray > Nisman 03/22/2015 at 01:04

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I'd go ahead and get new pads too. Every time I do rotors I get new pads just so everything wears at the same pace. Pads are cheap so its worth the money for new ones.

I'd suggest keeping the used pads as backup for next time you need to replace them. Save some money in the long run.

AMGtech - now with more recalls! > mattc993 03/22/2015 at 01:09

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Yeah, I know, and I wasn't trying to berate you or anything like that. Honestly I'm just getting sick of people saying to me that they read this article and now every mechanic who ever did their brakes is a dumb ass. It's a great article, don't get me wrong, but it's made people overconfident in their knowledge of brakes and has apparently given everyone the right to refute every brake related scientific fact ever in the history of the universe.

Okay, exaggeration here for sure. But hopefully you get what I mean.

AMGtech - now with more recalls! > Buick Mackane 03/22/2015 at 01:13

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You can reuse pads, however stopping power will be reduced for a time until the pads and rotors have worn in to each other.

I can't say that I haven't done this, to try to eliminate a noise, but I don't recommend it. If you spend a little more on the pads or try a different brand they may already cone with beveled edges.

AMGtech - now with more recalls! > Nisman 03/22/2015 at 01:17

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You can reuse pads, however stopping power will be reduced for a time until the pads and rotors have worn in to each other. How much stopping power is reduced and for how long varies with how worn the parts are and how the vehicle is driven mostly.

mattc993 > AMGtech - now with more recalls! 03/22/2015 at 01:40

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Meh, you generally won't hear me calling people who wrench idiots.

...and I totally understand the sentiment.

Frank Grimes > AMGtech - now with more recalls! 03/22/2015 at 02:01

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I dont think its just semantics. warping is completly different than pad material transfering to a rotor.

warp

become or cause to become bent or twisted out of shape, typically as a result of the effects of heat or dampness.

I dont think many people wouldnt understand a brake pad transfering unevenly to a rotor.

Buick Mackane > AMGtech - now with more recalls! 03/22/2015 at 02:20

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I have purchase many sets of brake pads in my life (not top end, expensive brake pads) but decent, well known manufacturers, and I have never seen a beveled edge yet on new set of brake pads. I suppose one could bevel the edges with a bench grinder or use a Dremel. By the way, what exactly is a "break-in" procedure for new pads?

Buick Mackane > Nisman 03/22/2015 at 02:32

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I recently watched an episode on TV , not sure what show it was (maybe Two Guys Garage or something like that) where they showed the benefits of the Raybestos brand disc rotors, they have a thicker steel discs on each side to eliminate "warping" or pulsating. Has anyone here had a good experience with Raybestos discs and pads? What does everyone here prefer, ceramic or semi-metallic pads? It seems every time I replace pads and rotors the pulsations come back after a few months with the new brakes installed.

Squid > Nisman 03/22/2015 at 02:47

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Nothing wrong with using the same pads, just scuff the pads up a little bit with a scotchbrite pad to get the glaze off and bed the pads in on the new rotors. it may take a while to get full mating of the two pieces but if you bed them in it will accelerate the transfer layer and help you in the long run. Really just look at the condition ofthe pads when you do the brakes and see if they are cracked or anything and when in doubt buy new pads. New pads and rotors is cheap peace of mind when you need to stop. Just don't buy more brake than your tires can handle. . . then you become friends with lock up city and bad things all around...

Also, you may want to try to engage your ABS if you haven't engaged that in a while just to make sure it works, if your car is equipped with it.

AMGtech - now with more recalls! > Frank Grimes 03/22/2015 at 03:33

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Fair enough. But it also isn't as simple as just material transfer. If material builds up on one side of the rotor but not the other (on the same face), those two sides well wear at different rates, which could be measured in runout or thickness variation. How would you measure for warping in a shop? Runout.

Though I maintain that the average owner has no idea how most things mechanical work, nor do they care to learn. I'm not saying they're stupid, just disinterested. You have to make things as simple as possible, the fewer words the better. If you don't, they will get bored, decline all repairs, and then leave. Obviously not all are this way.

AMGtech - now with more recalls! > Buick Mackane 03/22/2015 at 03:42

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http://www.stoptech.com/technical-supp…

ffoc02 > Nisman 03/22/2015 at 07:15

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I'm personally not a fan of reusing pads, no matter how old they are, but definitely clean the surface of the old pads if you are going to reuse them. When I need to reuse pads, I take a sheet of 80 grit sandpaper on a flat surface and rub the pad over it until the whole surface is clean and flat. They will still take longer to properly break in than new pads, but you should be OK.

Also, make sure any corrosion on the edges of the pad is thoroughly cleaned and coated with brake grease before resembling.

OPPOsaurus WRX > Nisman 03/22/2015 at 08:42

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I think the pistons spiral as they go back into the caliper and you may need a special tool to make it do that. not 100% sure so check on that.

Nisman > Nisman 03/22/2015 at 15:12

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So here's what I did. Talked to my mechanic buddy and he said use the old pads. I "prepped" the pads by scraping the excess gunk and brake dust off of them. Put them back on the new rotors. Didn't even re-grease because I did that a few months ago and everything was still fluid. They are 100% noise free. Not a peep and they stop great. I'll be taking it easy on the rotors for at least 1k miles to break them in properly. There is no need to do a bed in procedure when just replacing rotors, based on what I've read.