Brake job every 5k...

[Nikolas]

My WRX has been plagued by brake problems since new. Long story short, every 5k miles, the rotors would begin vibrating, i'd go to the dealer and have them turned. After 5k the same story.

Last time this happened, the rotors had been turned a few times, so there was little life left to them. The dealed agreed to replace them (OEM, under warranty). Since I needed new pads, I put a set of Hawk HPS. All was nice for (guess?) 5k miles, and now we're back to the same symptoms.

What happens is that after a couple of 85 to 50 mph slowdowns, they start vibrating the wheel. And it's so bad that they don't just shake when braking, but under cruising too, at least until they cool down.

I will go bark at the dealer, but my warranty is up, so I don't expect much to happen. Quite honestly, they had several attempts to fix it, but they didn't. I'd rather pay out of my pocket and have it fixed for good. So, since I will probably be paying for this myself, is there a moderately priced (the cheaper the better!) rotor/pad combo that does the trick? I'm under the impression that the brand of rotor doesn't matter that much, they all work the same. I don't really need any fancy drilled ones etc.

Any input is welcome, and thanks in advance.

P.S. Am I doing something wrong with the car to go through brakes like that???

 

[rpn453]

Overtightening the lug nuts can cause rotor warping.

 

[rat]

Agreed. The techs at the dealership I work at have been told to hand torque all lug nuts and DO NOT just zip them on with their impact guns. Too many comebacks for warped rotors.

 

[Nikolas]

I know that overtightening can cause that. I would like to believe that they are not stupid enough to make the same mistake 5 times. The other possibility is that the rotors are so weak that they warp if you stare at them long enough

So, if they don't agree to pick up the tab on this one (the warranty is over) what should I go for?

 

[Quest]

lemme see:

- improperly torqued lug nuts will contribute to rotor warping
-partially seized/stuck caliper will cause warping
-partially dragging brake pads will cause warping (uneven heating)
-if you have a mechanical brake distribution system (proportioning valve) and uneven weight load on your vehicle, you may experience warpage on one side of the braking system.

So many things to look into....

 

[Throckmorton]

Make sure your rotors are properly bedded-in. The diagnosis of warped rotors is often wrong; usually this can be attributed to poor bedding-in of rotors. Here's some tech info from StopTech:

"uneven pad deposits on the rotor face are the number one, and almost exclusive cause of brake judder or vibration.

Let's say that again, just so there is no misunderstanding. Uneven pad deposits on the rotor face are the number one, and almost exclusive cause of brake judder or vibration.

It only takes a small amount of thickness variation, or TV, in the transfer layer (we're only talking a few ten thousandths of an inch here) to initiate brake vibration. While the impact of an uneven transfer layer is almost imperceptible at first, as the pad starts riding the high and low spots, more and more TV will be naturally generated until the vibration is much more evident. With prolonged exposure, the high spots can become hot spots and can actually change the metallurgy of the rotor in those areas, creating “hard” spots in the rotor face that are virtually impossible to remove.
http://www.stoptech.com/tech_info/wp_bedintheory.shtml

A description of how to bed-in your brakes to prevent this from happening appears on the link above:

"Bedding-in Street Performance Pads

For a typical performance brake system using street-performance pads, a series of ten partial braking events, from 60mph down to 10mph, will typically raise the temperature of the brake components sufficiently to be considered one bed-in set. Each of the ten partial braking events should achieve moderate-to-high deceleration (about 80 to 90% of the deceleration required to lock up the brakes and/or to engage the ABS), and they should be made one after the other, without allowing the brakes to cool in between.

Depending on the make-up of the pad material, the brake friction will seem to gain slightly in performance, and will then lose or fade somewhat by around the fifth stop (also about the time that a friction smell will be detectable in the passenger compartment). This does not indicate that the brakes are bedded-in. This phenomenon is known as a green fade, as it is characteristic of immature or ‘green' pads, in which the resins still need to be driven out of the pad material, at the point where the pads meet the rotors. In this circumstance, the upper temperature limit of the friction material will not yet have been reached.

As when bedding-in any set of brakes, care should be taken regarding the longer stopping distance necessary with incompletely bedded pads. This first set of stops in the bed-in process is only complete when all ten stops have been performed - not before. The system should then be allowed to cool, by driving the vehicle at the highest safe speed for the circumstances, without bringing it to a complete stop with the brakes still applied. After cooling the vehicle, a second set of ten partial braking events should be performed, followed by another cooling exercise. In some situations, a third set is beneficial, but two are normally sufficient.
Bedding-in Club Race or Full Race Pads

For a typical performance brake system using race pads, the bed-in procedure must be somewhat more aggressive, as higher temperatures need to be reached, in order to bring certain brands of pad material up to their full race potential.

We typically recommend a set of ten partial braking events, from 60mph down to 10mph, followed immediately by three or four partial braking events, from 80mph down to 10mph. Alternately, a set of eleven stops, from 80mph to 40mph, or a set of seven stops, from 100mph to 50mph, would be approximately the same. As with street pads, each of the partial braking events should achieve moderate-to-high deceleration (about 80% of the deceleration required to lock up the brakes and/or to engage the ABS), and they should be made one after the other, without allowing the brakes to cool in between.

Again, depending on the make-up of the pad material, the brake friction will seem to gain slightly in performance, and will then lose or fade somewhat about halfway through the first set of stops. This does not indicate that the brakes are bedded-in, except where race-ready pads are being used. This phenomenon is the same as that which occurs with high-performance or street pads (except that, when race-ready pads are used, they do not exhibit green fade, and they will be bedded-in after just one complete set of stops).

As when bedding-in any set of brakes, care should be taken regarding the longer stopping distance necessary with incompletely bedded pads. This first set of stops in the bed-in process is only complete when the recommended number of stops has been performed - not before. As a general rule, it would be better to perform additional stops, than not enough. The system should then be allowed to cool, by driving the vehicle at the highest safe speed for the circumstances, without bringing it to a complete stop with the brakes still applied.

After cooling the vehicle, a second set of the recommended number of stops should be performed, followed by another cooling exercise. In some situations, a third set is beneficial, but two are normally sufficient.

Racers will note that, when a pad is bedded-in properly, there will be approximately 2mm (0.1 inch) of the pad edge near the rotor, on which the paint will have turned to ash, or the color of the pad will have changed to look as though it has been overheated.

In summary, the key to successfully bedding-in performance brakes is to bring the pads up to their operating temperature range, in a controlled manner, and to keep them there long enough to start the pad material transfer process. Different brake system designs, pad types, and driving conditions require different procedures to achieve a successful bed-in. The procedures recommended above should provide a useful starting point for developing bed-in procedures appropriate to individual applications. "
http://www.stoptech.com/tech_info/wp_bedinstock.shtml

 

[Nikolas]

First of all, thanks for the input!

The car is less than 3 years old, so the calipers should be in decent condition... but that doesn't exclude the possibility of a stuck one, given the salt on the roads etc. The other possibility is that the lug nuts were overtightened at some point.

Now, the question is how to fix the situation. Assuming that we fix the stuck caliper, and that the stars align so that the lug nuts are torqued properly, what do we do about the rotors and pads? One solution is to just replace rotors AND pads, but that is not too economical.

My concern is that once a rotor has been subjected to the kind of stresses (being uneven deposits, or just warped) that cause the vibration, then even after it is turned, it will have the tendency to warp again once heated. Is that the case?

The other question is what to do with the pads. They are fairly new so I don't want to toss them. After the rotors have been replaced or resurfaced, what to I have to do with the original pads? Sandpaper the surface?

Again, I don't want to be cheap with something vital like brakes, but I want to avoid changing parts unneccessarily. Thanks!

 

[RH+G]

Did you break the Hawks in as stated?

 

[doitmyself]

My question, which you are not going to like, is....if this has been a problem "since new" and repeatedly repaired under warranty, why are you letting the company off the hook to not fix the problem?

Why are you accepting the responsibility to maybe undertake many hundreds of dollars of future repairs that the company may be responsible for?

Did you inquire about any TSB's or "secret warranties" regarding this problem?

Is it too late to pursue making them take responsibility?

In most states, lemon laws protect you for problems not fixed after many attempts.

Sorry to be negative.....just wondering why this story doesn't quite add up.

 

[tom slick]

My Mazda had a problem with "warped" front rotors. Research on some mazda forums indicated an issue with OEM rotors. some cheap aftermarket rotors and new satisfied pads and I have not had an issue in 80k miles!

 

[alreadygone]

Sounds to me like one of the few cases where slotted and drilled rotors might be worth trying.

Bob

 

[ThirdeYe]

My mom had issues with her brakes on her Malibu as well, had them replaced once at around 20k because of warped rotors, and again at 50k. Poor design on the Malibu, as I hear most of them have that problem. I recommended that she tried aftermarket brakes this time around, and they're working good so far.

 

[Doc8404]

straight up Brembo OEM replacements should solve the issue.....with NEW brake pads of course.

 

[unDummy]

Buy a set of name brand rotors. Then, get them cryo'd. Use a race and not street pad. You'll have to live with noise/dust/rotorwear. HP+ is the next step over HPS.

Since you're cooking your rotors, find a brake rotor duct kit to help keep them cool.

If its in your budget, you need larger rotors. The problem with economy cars is that much is lacking when throwing HP at them. Brakes are a common issue with any vehicle with more HP!

Never turn rotors. That makes them thin and they become more of a problem.

You didn't mention rim/tire size, power mods, or year? The WRX has infinite aftermarket support.
If you're lacking in the brakes, upgrade them.

New brakes need to be bedded in. Entire brake systems should be bled. I'm guessing that these steps, along with torque wrench ignorance, are the causes of your brake problems.

 

[Nikolas]

Thanks everyone!

It seems that I need to go the "expensive" route to solve the problem... but it's brakes, not a part to save money on.

My question is about the rotors again. I was checking out the Brembos at tirerack. The have OEM replacement for about $50 per, and the slotted ones for about $170 per. Are the slotted ones 3 times better, since they cost 3 times more? Or is it just for the looks?

The other question is pads. I am using the HP+, (not HPS, my mistake), so is there anything to gain from going with a milder pad? The HP+ grab well when hot, but are they too agressive for (spirited) street use?

@ unDummy: The car is as stock as it gets. I don't subscribe to the fast and the furious philosophy. My idea is to first sort the suspension and the braking, and then go faster on a straight line!

 

[unDummy]

Slotted or drilled rotors aren't worth 3x the price. Get the cheaper blanks and search online for a cryo shop. Or, get the frozen rotor blanks.

If the HP+ are working for you, then keep using them. Pad type is a personal preference.

Since no rotor brand or pad type will make up for overheating the brakes, you need to improve their cooling. Duct work 'em.

 

[JakeR22]

Slotted rotors are just for looks.

 

[VelociRacer]

i have a 99 civic coupe 5sp with the same problem. after over 125k trouble-free miles on the factory pads and rotors, they finally hit the squeal tabs. I jumped at the opportunity and replaced them with Hawk HPS and Duralast rotors. Especially since I heard nothing but good things about HPS or Duralast.

Did not break in per StopTech instruction, just drove gently for at least 500 miles. Result after only a few k miles was pulsing and steering vibration while braking.

Replaced only rotors with Brembo blanks. Break in was gentle driving again. Same pulsing and steering wheel vibration.

Replaced brembos with new ones, same break-in, same result.

Now on my 4th rotor (Duralast) in less than 2 years and again, same break-in and same result.

Next step is to go back to OEM pads (I autocross, so no track pads necessary), and Duralast rotors. I plan to follow the StopTech break-in for street very carefully.

The common factor in all the previous attempts was the Hawk HPS and the bed-in process. Hawk HPS are either one overrated hunk of junk, or very demanding in the bed-in process.

I would not hesitate to buy Duralast rotors. Having gone thru so many rotors in the last 2 years, I saw nothing bad about them next to brembo blanks. don't bother with slotted or drilled, these are for boy racers (looks only).

 

[Nikolas]

Velociracer: That's the break in I followed too. I don't know, maybe that's the problem, on the other hand I can't just get on 93 (I live in Boston) and start doing 50 to zero stops to break the pads in... I'll have much bigger problems such as as being rearended!

So, there seem to be two plausible solutions. Brembo blanks and HP+ pads (more expensive) vs cheapo rotors and some less agressive pads that are less finicky (regular AZ stuff? axxis deluxe?)

Anyone having any experience with a similar setup, please let me know!

 

[WindyCityPilot]

If you bought the car new and you've had the dealer can't fix the issue. Lemon law.....new car. If they can't fix it in 3 tries let them take back the POS and give you a new one.