Brake rotor high pitch whine at 1/3 pedal pressure, dealer no help, seeking advice...

[copdocpvd]

2006 300C, 14,100 miles (that number is important...)

At about 12,000 miles I started noticing an exceptionally high-pitched whine when applying the brakes GENTLY at moderate speeds (under 40 mph).

Didn't seem to happen until the brakes had warmed up a little bit (in other words, didn't happen the first few miles/stops, but after a little bit of driving), and wouldn't happen if stronger pressure was put on the brake pedal.

Stopping effectiveness didn't change, and it was a much higher pitch than the typical "brake pads are going bad" sound, so I kept an eye...er, an ear on it.

Got worse, to the point that if I was gently coming to a stop at a red-light, I'd get people looking over.

Took it to a Dodge dealership (nearest Chrysler shop is a bit of a drive, Dodge shop is 4 miles away). They had it for 4 days for that and a vibration noise at WOT in the middle of the dash. I picked the car up, and surprise surprise, neither issue was fixed.

Took another morning off work, returned the car, had to take the "head mechanic" out with me for a drive, he claimed he couldn't hear the whine, so I rolled down the windows, he still couldn't hear it, so I had him sit in the driver's side, and THEN he heard it.

They fed me a line of sh*t about "well, it's just normal metallic noise blablabla...brake pads do that blablabla...we can try and fix it but it might get worse blablabla" and I told them to make it happen.

Came back next day, their "fix" was to turn the rotors and burnish the OEM pads (which had a ton of pad material left), which they listed on the service sheet as "de-glazing."

No surprise to me, the noise is still here.

I returned again, the Service Manager has told me that because the car is over 12,000 miles (despite that I had the issue before the magic 12K number turned on the odometer), that he could change the rotors or pads or "...whatever it is you think you want, but it'll be on your dime..." He also fed me the same line of crap again about it being "metallic particles in the brake pad will do that, you probably need to just wear them in."

I looked at him and said, "oh, you mean BED THE PADS IN?"

He looked at me dumbly.

I said "you mean, brake gently to warm up the disks so as not to shock the pads and disks, then bring the car to 60 mph, brake as hard as I can, just shy of activating the ABS, all the way to just before full stop, then accellerate again, until the brakes cool down again, and repeat that about eight times, then do it at 80 MPH? Yeah, I did that, and even threw in four runs at 100mph, being absolutely certain that the brakes were completely cool before coming to a full stop so as not to risk 'burning' brake pad material onto the hot disks which can cause noise and reduce braking effectiveness."

"Uh, um, yeah, that..." he replied.

Then I told him for the fifth time, "I really do NOT think this is a brake pad issue, my friend, I know a tiny bit about what I am talking about."

So...I look to my fellow forum members.


Experience with this specific issue?

Is it some kind of harmonic or issue with the Rotor and not the pads?

How to fix it?

Any clue on how to address it with Chrysler? (I definitely have had enough of that particular Dodge dealership)


(PS, last week I had an idiot pull in front of me, had to panic stop and the car stopped like I threw out ten anchors, so the brake system WORKS fine, so this high-pitched gentle-braking whine isn't symptomatic of functionality problems, but it's driving me friggin' nuts...).


Many thanks in advance for your help.


Pete

[2005rtmag]

I had this experience with a Honda Civic. I had been braking gently because the service manager had warned me that the pads wore out very quickly on this car. I thought the pads were worn out even though the mileage was very low. I checked the pads and they were like new.

I started braking much harder and the noise went away!

[bigjim]

Time for you to do some reading so you REALLY understand what brake bedding is for and why brakes work SO well after it is done. That being said, find a local shop that does brakes on performance cars and pay them to diagnose and lower your NVH. It will be worth the few dollars you need to spend. I have replaced my brakes at 80,000 miles and used all OEM stuff to preserve the actual design of the system and have had some noise from day one (10/2004) to my current 122,000 mile mark. They are big high performance brakes and do make more noise than a Honda civic to begin with, is it possible that you can find another local member and compare sounds?

[Tbird100636]

There's a couple of things I've found cause brake squeal. One, rust ridges develop where the pads don't ride, a small edge that gets bigger and eventually contacts the edge of the pads creating squeal. I know surface rust can develop on the braking surface overnight but this is not thick rust that can develop on the outer edges where the pads don't ride. Haven't had this happen on an LX yet, or in a long time in general. Since you said they turned the rotors we can eliminate that as a possibility. The other is the pad backing plates shims. In rare cases, the caliper can rub through the thin shim on the backing plates of the pads and cause a squeal. Squeal is caused from metal vibrating against metal. Pull the calipers and look at the pad backing plate shims where the calipers push on If it's rubbed through to metal you've found your noise. You can either replace the pads and apply disc brake quiet to the backing plates to prevent the rub through or try putting the disc brake quiet on the old pads as directed. It comes in a squeeze bottle with a nozzle, CRC makes a red kind, Mopar's is blue. FOLLOW THE DIRECTIONS ON THE BOTTLE. IT GOES ON THE BACKING PLATES, NOT THE LINNINGS. DO NOT BUY THE BRAKE QUIET THAT GOES ON THE LINNINGS, IT IS A WASTE OF TIME AND TYPICALLY RESULTS IN THE BRAKES TO GRAB. Give it a try and see what you get.

[copdocpvd]

Time for you to do some reading so you REALLY understand what brake bedding is for and why brakes work SO well after it is done. That being said, find a local shop that does brakes on performance cars and pay them to diagnose and lower your NVH. It will be worth the few dollars you need to spend. I have replaced my brakes at 80,000 miles and used all OEM stuff to preserve the actual design of the system and have had some noise from day one (10/2004) to my current 122,000 mile mark. They are big high performance brakes and do make more noise than a Honda civic to begin with, is it possible that you can find another local member and compare sounds?

Bigjim, Not sure I understand the first part of your post...I think I do understand the purpose of brake bedding.

stoptech.com puts it better than I as: "...Simply stated, bed-in is the process of depositing an even layer of brake pad material, or transfer layer, on the rubbing surface of the rotor disc." and "...the objective of the bed-in process is to deposit an even layer of brake pad material, or transfer layer , on the rubbing surface of the rotor disc..."

for more, see: http://www.stoptech.com/tech_info/wp_bedintheory.shtml

and http://www.zeckhausen.com/bedding_in_brakes.htm

Am I missing something here?


As to comparison against another 300c, great advice, and I am happy to say I did the same thing with two 300c's (my neighbor and his father have a 2005 and a 2007).

While both exhibit what I would describe as "normal metallic sounds" during braking, which is identical to what I would describe from my right front brake rotor/disk, both under light, moderate, and heavy braking application (that I would expect from metallic or semi-metallic pads), neither of theirs exhibit the high-pitch whine that I get from my left front brake/rotor/disk, only under about 1/3 braking application.

============================

There's a couple of things I've found cause brake squeal. One, rust ridges develop where the pads don't ride, a small edge that gets bigger and eventually contacts the edge of the pads creating squeal. I know surface rust can develop on the braking surface overnight but this is not thick rust that can develop on the outer edges where the pads don't ride. Haven't had this happen on an LX yet, or in a long time in general. Since you said they turned the rotors we can eliminate that as a possibility. The other is the pad backing plates shims. In rare cases, the caliper can rub through the thin shim on the backing plates of the pads and cause a squeal. Squeal is caused from metal vibrating against metal. Pull the calipers and look at the pad backing plate shims where the calipers push on If it's rubbed through to metal you've found your noise. You can either replace the pads and apply disc brake quiet to the backing plates to prevent the rub through or try putting the disc brake quiet on the old pads as directed. It comes in a squeeze bottle with a nozzle, CRC makes a red kind, Mopar's is blue. FOLLOW THE DIRECTIONS ON THE BOTTLE. IT GOES ON THE BACKING PLATES, NOT THE LINNINGS. DO NOT BUY THE BRAKE QUIET THAT GOES ON THE LINNINGS, IT IS A WASTE OF TIME AND TYPICALLY RESULTS IN THE BRAKES TO GRAB. Give it a try and see what you get.

tbird, thank you very much.

I looked at the pads per your advice, and the shims are fairly pristine. Plenty of pad material left as well, and you were correct--no rust on the rotors.

Only 14K miles on the car, the rotors are as thick as Rosie O'Donnell's head, and I'd much rather spend money on a Diablo Predator than swap out brake pads and perhaps even rotors that are functionally perfect but just like to squeal like Ned Beatty on the left side only, and only when the proper recipe of "just the right pedal pressure, no more, no less + brakes already warm + precisely when it would be frustrating to me and potentially embarassing" exists.

But it sure seems to me that if it was a "well, this is just because you have metallic or semi-metallic brake pads" thing, that my 8 runs at 60 mph, 6 at 80 mph, then 4 at 100 mph (uh, um, on a closed course, Officer!) to make sure the pads were properly bedded in (unless you know otherwise, bigjim?), having the pads re-surfaced and the rotors turned by the dealer, and that I get the noise not "almost all the time" but only under specific pressure suggests it's something different?

And if so, are there any bullets to put in my "take it to Chrysler gun" that would allow me to get it resolved without it costing ME money I'd rather spend on more goodies?

(tbird, I guess I'm saying I don't think it's a brake-pad-to-rotor issue, per say, particularly because the shims look good--should I put the stop squeak on the backs of the pads anyway? If I say "screw it" and get higher-performance pads, would I have to bleed the brake fluid, or could I just swap the pads?)


Pete

[36 chambers]

mines been sqeeling for months!!! think oits finally going away.. dont think 22s help!!!

[Tbird100636]

Bigjim, Not sure I understand the first part of your post...I think I do understand the purpose of brake bedding.

stoptech.com puts it better than I as: "...Simply stated, bed-in is the process of depositing an even layer of brake pad material, or transfer layer, on the rubbing surface of the rotor disc." and "...the objective of the bed-in process is to deposit an even layer of brake pad material, or transfer layer , on the rubbing surface of the rotor disc..."

for more, see: http://www.stoptech.com/tech_info/wp_bedintheory.shtml

and http://www.zeckhausen.com/bedding_in_brakes.htm

Am I missing something here?


As to comparison against another 300c, great advice, and I am happy to say I did the same thing with two 300c's (my neighbor and his father have a 2005 and a 2007).

While both exhibit what I would describe as "normal metallic sounds" during braking, which is identical to what I would describe from my right front brake rotor/disk, both under light, moderate, and heavy braking application (that I would expect from metallic or semi-metallic pads), neither of theirs exhibit the high-pitch whine that I get from my left front brake/rotor/disk, only under about 1/3 braking application.

============================



tbird, thank you very much.

I looked at the pads per your advice, and the shims are fairly pristine. Plenty of pad material left as well, and you were correct--no rust on the rotors.

Only 14K miles on the car, the rotors are as thick as Rosie O'Donnell's head, and I'd much rather spend money on a Diablo Predator than swap out brake pads and perhaps even rotors that are functionally perfect but just like to squeal like Ned Beatty on the left side only, and only when the proper recipe of "just the right pedal pressure, no more, no less + brakes already warm + precisely when it would be frustrating to me and potentially embarassing" exists.

But it sure seems to me that if it was a "well, this is just because you have metallic or semi-metallic brake pads" thing, that my 8 runs at 60 mph, 6 at 80 mph, then 4 at 100 mph (uh, um, on a closed course, Officer!) to make sure the pads were properly bedded in (unless you know otherwise, bigjim?), having the pads re-surfaced and the rotors turned by the dealer, and that I get the noise not "almost all the time" but only under specific pressure suggests it's something different?

And if so, are there any bullets to put in my "take it to Chrysler gun" that would allow me to get it resolved without it costing ME money I'd rather spend on more goodies?

(tbird, I guess I'm saying I don't think it's a brake-pad-to-rotor issue, per say, particularly because the shims look good--should I put the stop squeak on the backs of the pads anyway? If I say "screw it" and get higher-performance pads, would I have to bleed the brake fluid, or could I just swap the pads?)


Pete

The pad shims are a caliper-to-pad issue. Give the brake quiet a try. Can't hurt anything. Put it on per the instructions. Make sure its clean first. Get a can of brake clean and get the pads and cailpers clean. They sell good brake cleaner at any parts store. Don't bother with the Mopar brake clean, it does not clean well enough. I understand you don't want to spend more money. The brake clean and pad quiet isn't that much money compared to specialty pads (Granted, I haven't priced any out, but still pads are more money than brake clean and brake quiet.). Other than that make sure the anti-rattle clips are there and not damaged.

[bigjim]

No, you are NOT missing anything! I presumed (Bad Jim) that you were part of the majority that doesn't get the purpose of bedding and thought it was a good time to resurect the discussion. I have seen the after market stuff NOT transfer the material onto the rotors and work like crap, make noise, dust and work like poo! You are on the right track, I use a version of brake quiet on everything I assemble and simply wont do a brake job without it, in spite of some versions being a bit of a gooey mess when assembled, worth the time for a try.
Jim

[wadertmag]

If you did not make a dealership aware of the issue prior to 12k miles the only way you are going to get free help is out of the kindness of a service manager. (all of the warranty info is well defined in the owner's manual) I would try your selling dealer for the best chance of that. But glazing is kinda common on the LX platform, it usually comes from the rear. turning the rotors and sanding the pads usually clears it up.

Wade

[thewagon]

I had a very similar situation, slight brake pedal pressure, it would squeal. Less brake pressure, squeal gone, more pressure, squeal back.
I identified it came from front left side. Took wheel off did the following:

Pad wear at 53k miles



pad surface appearance



one piston before cleaning



same piston after cleaning



and with disc quiet applied as per instructions


Problem squeal is gone....for now...knock on wood.