Posts Tagged ‘shims’

Racingbrakes are Talking To Me: High Pitched Squeaking Under Light Brake Pressure at Moderate and Low Speeds

Tuesday, May 11th, 2010

The topic of Racingbrake ET500 pads and 2-piece rotors has come up now twice in 24 hrs, telling me this is an issue that warrants official comment in the Pitboard.

Racingbrake 2-piece rotors and ET500 pads installed on 04-08 TL w/ Brembo

Racingbrake 2-piece rotors and ET500 pads installed on 04-08 TL w/ Brembo

The first occurrence of comment came directly off the Racingbrake forums: Link Here to Thread

In summary, vinman1000 had installed these parts on his TL and was extremely pleased with the performance upgrade, if only to notice a squealing noise under light pedal pressure at lower speeds. Racingbrake recommended re-bedding to quell the noise, which worked for a short time only to have the squealing return days later. Despite Racingbrake’s recommendation to install the ET500 pads without the factory shims, the customer installed them to see if it would impact the sound. They noticed a slight change in braking performance, but the customer was relieved to report the sound had not returned after a week of driving. To their dismay the customer had to report that the noise did ultimately return and was looking for another solution. At this time, RB contacted me to chime in on the matter.

Before I get to the reply, I will report on the second contact we have gotten on the matter, just this morning in our Priority Response Center, coming from the same combination of parts. Email read as follows:

Subject: Racingbrakes noise:
i bought your racing brakes for my 06 acura tl auto. 2 piece front with et 500 pads, along with the rear new rotors and pads. I have about 5-8k miles on it now, upon slight braking mostly when warm, sometimes cold it makes the noise.

My total reply to these two customers as well as to anyone else using any other brake parts experiencing the same noise (loud, high pitched squeaking under light brake pressure at moderate and low speeds, no shaking or loss in performance) is as follows:

The noise is completely normal for any good braking system. I would caution against expecting total silence out of brake parts that provide confidence and stopping power. Japanese car brakes are usually not as effective as their European counterparts because they place focus on quietness and less dust over actual function and effectiveness. European manufacturers build their brakes to specs that will provide a benefit in braking performance and safety. In actuality, the parts which Acura and Honda drivers purchase as upgrade items are only marginally better than the standard brakes on your garden variety BMW at best. As might be expected, BMW brakes make a horrific amount of dust and a moderate amount of noise when they get 1-2 weeks long in the tooth of a good cleaning. The factory Honda systems are often criticized because of prevalent shaking and lack-luster performance, but are never really credited for being quiet and low dusting. When we upgrade our Acura and Honda brakes, we expect all attributes to either remain the same or improve. Finding the increase in performance and the increase in noise may turn off a driver, but we encourage that driver to take things into perspective more.

My observation is that with any braking setup there is a buildup of dust that occurs over the course of time. This contributes to a high pitched squealing noise that mostly occurs with light, street-type braking pressure. Higher braking forces do not cause the squeak since heat will clear away the buildup which causes the noise. Most frequently the noises that occur normally in the system will rear their head in stop-and-go situations or in between stoplights*. The customer might notice an intermittent squeaking whose resolution co-insides with car-washes. Washing out the wheels and brakes clears out brake and rotor dust from the friction surface and the slots and the squeaking goes away temporarily…until they get dirty again. Shims and grease have nothing to do with it. The nature of the pads and the dust buildup combined with consistent light pedal pressure cause the squeaking.

My TSX with ET500 and 2-piece does this, as has almost every other car I have owned with nearly any other braking parts. The only thing that changes is the frequency with which I need to rinse out the wheels to keep things quiet. Lesser brakes go longer without noise. Look for an association with the squeaking more when you have dusty buildup on your wheels, as evidence than there is buildup in the system.

In short the noise outlined here should be considered to be completely normal. If there is a trade off for the superb performance and life these parts have it is going to be this bit of noise. I myself am mildly annoyed by the sound but chock it up to the brakes working as they should giving me confidence to brake as hard as I want, and largely attribute the noise to scolding for not cleaning things as often as I should. Weekly or bi-weekly washes keep it to a minimum, and there I find the compromise acceptable. Another way to reduce the noise is to break with higher pedal pressures. Being gentle on the brakes as they make noise only serves to make the noise more prevalent.

For the customer who finds the noise truly unacceptable, a change in pads would reduce the noise. I would say that switching to ET300 pads would probably reduce the occurrence of the noise, probably altogether. Resurfacing really is not going to help at all**. You may just want a milder pad. On Racingbrake rotors we do suggest a minimum aggressiveness in pads though, not suggesting customers use anything other than Racingbrake brand pads. They are formulated to work best with Racingbrake rotors, and we have proven this through customer exchanges of product.

So, in summation, some noise from your brakes, contrary to popular belief, really is to be expected. I guess there isn’t any such thing as a free ride. The brakes will be quiet but then they won’t work optimally. They can stop great, but the side effects might rub you the wrong way. We encourage customers to choose the products which will most closely meet their needs in performance, practicality and economy. HeelToe offers this service on the phone and in the Priority Response Center. If you have any doubts prior to or after ordering we can help clear things up for you. Thanks for reading!


* Of note, we also attribute the stress of traffic increasing the impact the noise has on the driver. The noises happen most when drivers are stressed and irritated with outside factors causing the squeaking to have a greater impact on the driver’s attitude toward the car. When enough is enough, we just want that damn squeaking to stop! It is probably the only thing the person has relative control over in their commutes. Another contributing issue might be embarrassment a driver will feels when other people hear the noise; that the sound would indicate a sub-par car or lack of attention to service. The irony here is that just the opposite is true. The car is in great working form, but the noise is looked down upon by those who would favor silence over braking effectiveness.

** Indeed resurfacing is a completely bunk service that should not really need to be done in most cases. Only truly warped rotors really benefit from resurfacing, and in my mind are better off replaced with units that won’t warp. Many braking shakes are falsely accused of being warped when again it is more a pad issue than anything else. More aggressive pads should, at the minor expense of the noises above, cure many shaking issues.