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Thread: Front Raybesto QS "feel" seems odd

  1. #1
    Join Date
    Jan 2004
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    Default Front Raybesto QS "feel" seems odd

    I recently (about 3,000 miles ago) installed front Raybestos QS pads and new ATE stock type rotors on my 95 525i. No dust and no noise. However, the feel seems odd. I seem to need to push the brake pedel harder than with the dusty Jurid pad. Even so, it seems to stop fine.

    Is this a function of the pad or is something else causing it. My rear pads and rotors are rather old but not quite worn out. It has been about 18 months since my fluid has been changed. Not quite sure where to start except change the fluid. TIA
    Last edited by Russell; 10-30-2005 at 07:05 AM.
    Thanks,

    1995 525i Auto, M50TU 2.5L, EAT chip, 1/95 build, USA, 205/65/15 tires, ASC+T, HID, lumbar, EC Mirror, BMW Alpine 5 radio with BMW-Pioneer CD Changer, abt 236k miles, Oxford Green/Parchment

  2. #2
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    Default

    Quote Originally Posted by Russell
    Is this a function of the pad or is something else causing it. My rear pads and rotors are rather old but not quite worn out. It has been about 18 months since my fluid has been changed. Not quite sure where to start except change the fluid. TIA
    Fluid should be changed every 12 months. It sure made a difference in my car.
    BMW E34 528i, M52B28 + M50 manifold, Remus exhaust, ///M Parallel Spoke 18" rims

  3. #3
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    Default How did you do the install and how did you break

    them in? Did you clean the new rotors with brake spray cleaner and then clean them with warm water and detergent before installing? During the machining process particles of metal,cutting lubricant etc become imbedded in the the pores of the rotor and if you don't have the rotor pretty well degreased and cleaned before you install it, then it will tend to glaze over the surface of the pad and keep them from biting like they should.. I would take the fronts back apart, take some coarse sandpaper and rough up the surface of the pads, especially if they have a glazed shiny look to them. You have to rough them up pretty good to remove all the glazed appearance. The i would take the rotors and using a orbital sander or random orbital i would use more of that coarse sandpaper and rough up the surface of the new rotors until you have a swirl finish on the surface of the rotor on both sides, then clean the rotors up with warm water and detergent, rinsing well and drying. Reinstall and then try reseating the pads again. I have a feeling that you're an extremely careful person from your posts and you may have taken it too easy on the pads while breaking them in and now they are glazed.
    This always increases the pedal pressure needed when this happens.
    .

  4. #4
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    Default Did most of what you stated

    I cleaned the rotors with brake cleaner. However, I did not wash the rotors with hot soapy water. They felt and looked clean. No oily feel or surface grit. I thought that step was not needed. Looks like I may be wrong.

    I also thought I was using them hard enough to bed the pads. I also thougt that Raybestos stated bedding was not needed. Live and learn.

    I sure do not want to take everything apart again. Starting to get cold here and I have an unheated garage. Any alternatives ? Thanks
    Last edited by Russell; 10-30-2005 at 09:11 AM.
    Thanks,

    1995 525i Auto, M50TU 2.5L, EAT chip, 1/95 build, USA, 205/65/15 tires, ASC+T, HID, lumbar, EC Mirror, BMW Alpine 5 radio with BMW-Pioneer CD Changer, abt 236k miles, Oxford Green/Parchment

  5. #5
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    Default This is one of the many shop magazines that i get each month, usually

    like a form of paper spam, anyway a couple of years ago an issue of this had an article regarding brakes and in it they stated that most of the brake parts manufacturers are now saying to degrease new rotors with brake spray cleaner and then wash them with hot or warm soapy water to remove grease and particles that you can't feel blah blah.. Since i've started doing this i have had much better results with new pad and rotor installations as hard to believe as it may be..
    Anyway heres the site address for the brake and front end magazine you can search back issues etc for brake info.

    The qs that i've installed on a fairly large number of cars seems to have a very close to stock pads pedal feel.. it may take a very small amount more pedal effort but its so close as to be virtually the same. Most cars i put them on are so overboosted by the power booster that you wouldn't be able to feel the difference anyway



    Quote Originally Posted by Russell
    I cleaned the rotors with brake cleaner. However, I did not wash the rotors with hot soapy water. They felt and looked clean. No oily feel or surface grit. I thought that step was not needed. Looks like I may be wrong.

    I also thought I was using them hard enough to bed the pads. I also thougt that Raybestos stated bedding was not needed. Live and learn.

    I sure do not want to take everything apart again. Starting to get cold here and I have an unheated garage. Any alternatives ? Thanks

  6. #6
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    Mar 2004
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    Default

    Pads from different mfrs won't feel the same. Jurids like the factory pads have excellent bite when cold, but their bite doesn't improve as they heat up. Many aftermarket pads have poorer cold grip, but get improved grip as they heat up. Do you notice any change in bite after 2 abrupt stops from 60? With 3000 miles of normal driving, your pads are likely bedded in as well as they're going to get. Changing your fluid is a good idea, but I wouldn't expect it to reduce your pedal effort.

    Paul Shovestul


    Quote Originally Posted by Russell
    I cleaned the rotors with brake cleaner. However, I did not wash the rotors with hot soapy water. They felt and looked clean. No oily feel or surface grit. I thought that step was not needed. Looks like I may be wrong.

    I also thought I was using them hard enough to bed the pads. I also thougt that Raybestos stated bedding was not needed. Live and learn.

    I sure do not want to take everything apart again. Starting to get cold here and I have an unheated garage. Any alternatives ? Thanks
    .....Got to keep the loonies on the paath.

  7. #7
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    Default Thanks Guys.

    If I can find the time, I may clean/scuff the rotors and pads. I will replace the brake fluid.
    Thanks,

    1995 525i Auto, M50TU 2.5L, EAT chip, 1/95 build, USA, 205/65/15 tires, ASC+T, HID, lumbar, EC Mirror, BMW Alpine 5 radio with BMW-Pioneer CD Changer, abt 236k miles, Oxford Green/Parchment

  8. #8
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    Split, Croatia
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    Default

    Quote Originally Posted by Bill R.
    The qs that i've installed on a fairly large number of cars seems to have a very close to stock pads pedal feel.. it may take a very small amount more pedal effort but its so close as to be virtually the same. Most cars i put them on are so overboosted by the power booster that you wouldn't be able to feel the difference anyway
    Is there a way to control the boost? I have a feeling that my friend's E36 has a stronger power booster than my E34. Can worn rotors cause brakes to become less efficient? I've changed my brake fluid recently and the situation did improve, but not as much as I wanted.
    BMW E34 528i, M52B28 + M50 manifold, Remus exhaust, ///M Parallel Spoke 18" rims

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