I hate brakes....

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Hello All,

I made a similar post a while back about my brake issues:

http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3393228/Re:_Warped_Rotors_damage_brake#Post3393228

Since then I had went to AAP, they replaced my rotors AND brake pads, I paid the difference and went with ceramic. Well.. Everything had been fine, but recently.. I have once again started getting a pulsation in the brakes. I am fairly certain my calipers are in good condition, When I replaced the brakes last time, everything came apart, and went together super easy. The slide pins moved freely, I wiped them off and re-greased them. The caliper pistons pushed in easily, and the car does not pull to either side when braking...

Is there anything else I could be missing.. or is it just the AAP brake rotors?
 
Could be the rotors. I had a pair that warped in short order. The OEM's and the replacement for the replacement though lasted longer.

Is this for the Saturn, a brand known for warping rotors?
 
It could be lousy rotors.

Try NAPA Premium or Ultra Premium. My mechanic recommends these and refuses to install the super-cheap rotors that everyone seems to have these days.

Originally Posted By: supton
Is this for the Saturn, a brand known for warping rotors?

I had a '99 SL1 throughout college. It was driven in stop-and-go NY/NJ metro traffic every day and I put over 70k miles on it in 4 1/2 years. When the car was sold, it still had the original rotors and was on its second set of front pads.

*shrug* I know that's not data, but just my anecdote.

In hindsight, that car was remarkably reliable for the amount of abuse I put it through. The horn died around 30k miles. Otherwise it was a trouble-free 70k miles. Just oil changes and brake pads.
 
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I've had problems with rotors on my 84 Civic with warping. I think that I could be classified as easy on the brakes having routinely gone over 100K miles on front pads in the past. So this time I found a Brembo set of rotors and pads, paid more but no warping. There is a big difference in replacement rotors and you need to do your homework before either accepting what the mechanic supplies or what you purchase yourself.
 
Are your lugs torqued to spec? I have warped a rotor by overdoing the torque a little. Sometimes they fix themselves when I retoqued properly.
 
It's actually relatively rare that rotors warp. Most of the time it is pad buildup that does it. Pads often need to be bedded to the rotors. There are specific instructions on how to do it that come with the pads. It is important to follow the instructions or you can get pad buildup that will result in a pulsating pedal.

robert
 
My 2000 Saturn SL was the only one to suffer warped rotors. Every 20k I'd feel it, and put it off until 25k or so when I couldn't stand it. Same driving habits as other vehicles. Actually, on my Jetta I had a set of replacement rotors warp in short order, so I replaced just the rotors (reusing pads) and the replacements lasted 90k (replaced due to grooves and needed new pads anyhow due to rust concerns).

I can't argue with logic but I can't argue with my experience either. Maybe Saturns just have junky pads that really need bedding? Bedding being that which I've never done either.

Ceramics, those are coming on more new vehicles now. My Camry has them. Don't know what they do to them to make them "livable" for every day life. [It ate one pad at 55k, so it got new rear pads at that time, but I reused the rotors. Seems fine. Will be checking soon when I do tires.]
 
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Originally Posted By: robertcope
It's actually relatively rare that rotors warp. Most of the time it is pad buildup that does it. Pads often need to be bedded to the rotors. There are specific instructions on how to do it that come with the pads. It is important to follow the instructions or you can get pad buildup that will result in a pulsating pedal.

robert


AAP Pads come with no instructions.. so I just do what seems reasonable.. and what seems to be the norm for consumer grade pads, and go as easy as possible on the brakes the first 500 miles.
 
Originally Posted By: strat81
It could be lousy rotors.

Try NAPA Premium or Ultra Premium. My mechanic recommends these and refuses to install the super-cheap rotors that everyone seems to have these days.


Or Wagner premium rotors, or Centric. You can find them on Amazon and, amazingly, they ship for free with Amazon Prime. Using premium rotors is the way to go. I also no longer install the cheap store brand rotors, had a few too many issues with them. It's not to say that they are all a problem, most are fine, but it's not worth the headache.
 
robertcope could be right. It may be that pad material has been deposited on the rotors in a couple of localized spots where the rotor has come to a stop with the brakes still pressurized. The edges of the pads will tear off and leave lines of material on the rotor that cause the pulsing.
 
Originally Posted By: tinmanSC
Originally Posted By: strat81
It could be lousy rotors.

Try NAPA Premium or Ultra Premium. My mechanic recommends these and refuses to install the super-cheap rotors that everyone seems to have these days.


Or Wagner premium rotors, or Centric. You can find them on Amazon and, amazingly, they ship for free with Amazon Prime. Using premium rotors is the way to go. I also no longer install the cheap store brand rotors, had a few too many issues with them. It's not to say that they are all a problem, most are fine, but it's not worth the headache.

Since OP went to AAP, he could save some money by getting Whearever rotors (if he didn't already) which are reboxed NAPA premiums. So If he got the Whearevers, he already has the Napa premiums. Wagners are okay too, but I have personally had to exchange a few of them for the hats being OOR. Luckily they were readily available.
 
Originally Posted By: actionstan
Originally Posted By: robertcope
It's actually relatively rare that rotors warp. Most of the time it is pad buildup that does it. Pads often need to be bedded to the rotors. There are specific instructions on how to do it that come with the pads. It is important to follow the instructions or you can get pad buildup that will result in a pulsating pedal.

robert


AAP Pads come with no instructions.. so I just do what seems reasonable.. and what seems to be the norm for consumer grade pads, and go as easy as possible on the brakes the first 500 miles.


The normal kind of bedding procedure for racing pads is to close off the brake cooling ducts (if any), and go out and do a series of 10 moderate decelerations from 50-30 mph. Moderate meaning 50% effort before the wheels lockup. Then after the brakes have been heated, to drive the car without stopping until the brakes have cooled. This is supposed to deposit an even, thin coating of pad material on the rotor. After about the 5th or 6th brake application, the pad will heat up enough that it will start to outgas, boiling the manufacturing oils out of the friction material, giving off the "hot brake" smell, and causing the pedal to get hard while not providing the same deceleration. This is normal, but should be allowed for.
 
You get what you pay for.

All it takes is a single sweaty greaay finger print to cause this problem.

Time or money... do the job with quality parts once, or waste away your free time with cheap parts often.
 
Has anyone actually measured the warpage of rotors? I didn't think so. The cast iron of the brake rotors does not warp easily. If there is any actual warping, it is most likely to be in a conical shape, not axial run out. Even a new rotor will have some axial run out depending on how true the surface is on the hub where the rotor sits. 0.007" used to be the max standard. Some cars now limit it to 0.003" (three thousandths). I've measured new rotors once when installing them. New SP Performance rotors measured 0.003" runout measured with a dial indicator.

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

"Ceramic" on brake pads means little. There are different amounts of ceramic material in the pads of different makers and different quality lines, and many other materials. What is likely is that the pads that cause the judder are not adequate for the usage of that driver. They may be smooth, clean, problem free for my mother-in-law, and judder like mad for a driver like me.
 
Originally Posted By: robertcope
It's actually relatively rare that rotors warp. Most of the time it is pad buildup that does it. Pads often need to be bedded to the rotors. There are specific instructions on how to do it that come with the pads. It is important to follow the instructions or you can get pad buildup that will result in a pulsating pedal.

robert


Robert is correct. The Shade Tree will often blame the "cheap" rotors for this, when that is seldom the problem...
 
Bought the powerstop one click brake kit from rockauto.

One of the autospecialty made in china rotors was not machined correctly, and had grooves all over it.

That had to go back.

Waiting for the new parts to come in today and see how they do. I'm not sure what I expected for 68 dollars for 2 rotors and one set of pads.
 
Originally Posted By: robertcope
It's actually relatively rare that rotors warp. Most of the time it is pad buildup that does it. Pads often need to be bedded to the rotors. There are specific instructions on how to do it that come with the pads. It is important to follow the instructions or you can get pad buildup that will result in a pulsating pedal.

robert


Agree 100%. Most "warped rotors" are actually uneven deposits on the rotors.

Quote:



The normal kind of bedding procedure for racing pads is to close off the brake cooling ducts (if any), and go out and do a series of 10 moderate decelerations from 50-30 mph. Moderate meaning 50% effort before the wheels lockup. Then after the brakes have been heated, to drive the car without stopping until the brakes have cooled.


Agree with this advice- though I've never bothered to close the cooling ducts. New pads "outgas" quite a bit, and about the worst thing you can do is come to a hard stop then hold the brakes while the pads are still new. Its best to stop short at lights and occasionally roll forward a foot or two while waiting so that the pad moves around the rotor instead of sitting clamped to one spot. I try to do that all the time, in fact, though its not always possible.

Even after pads/rotors have developed a definite shimmy, I've had pretty good luck repeating the bed-in procedure above to burn the rotors clean again.
 
Don't blame rotors especially new ones (fresh castings from foundries), instead: blame most of them on improper preparation and handling of materials instead.

While some of them disc braking systems are notoriously known to develop warps sooner due to undersized rotors (rotors are also heat sinks, in case you don't know), most of them I've done so far has to do with the fact that for the most part, regardless of semi-metallic or ceramic (which I used mainly these days), there's some sort of magical combination between the 2 of them. i.e. I'm now using Wagner OE Spec or Monroe ceramics on chinese rotors, and they last until the next round of pad servicing (wornd out); on the other hand: combinations with Wagner TQ, regardless of Abutement materials, additional backing lubricants or not, I still develop slight squeals and/or rotor warpages in very short order (within 6~14 mnths most) no matter how meticulous I have been.

Mind you: I have been doing mechanical work for over 20+yrs now, and I can tell you my experiences.

certain racing (or race oriented pads) like Hawks tend to dust and squeal quite a bit, but the biting and bedding onto rotors (even chinese rotors) works out fairly well, and no warpage for a long, long time. Ditto with Akebono ProACTS I've been using on my Hondas.

Q.
 
I know many people online have it in their head that pad deposits cause most or all pulsation problems because of that one article that's been posted a million times, but other information indicates runout can be the cause. Runout causes the rotors to wear unevenly, which causes the pedal pulsation.

If you think you're having a pad deposit issue, then try rebedding. That has cured problems for me in the past that were likely pad deposits or other junk on the the rotors.

Since the OP is getting the problem again, I'm going to guess he has a runout issue, whether that's junk between the hub and rotor, rotors with too much runout from the factory, or a bad hub that now has too much runout.

Investing in a HF runout gauge will help ID the issue.
http://www.harborfreight.com/clamping-dial-indicator-93051.html


Read document 6-13 from Raybestos here for more on runout issues:
http://www.raybestosbrakes.com/magnoliaP...rview/2006.html
 
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