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  #1  
Old 10-06-2015, 03:23 PM
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changed brake pads, but when you press the brakes its really soft?

Hi,

I changed the front brake pads on my 2008 and for some reason the brakes feel soft. I have to push down a little more? What could it be? Ive done these before and never had this problem. The brake fluid never top over when i pressed down the caliper piston and the fluid is at its normal level.
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  #2  
Old 10-06-2015, 04:14 PM
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Different brake pads?
Going from OEM (whatever manufacturer it is) to Akebono pads definitely changed the feel.
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Old 10-06-2015, 04:17 PM
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Did you resurface the rotors and bed the new pads?
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Old 10-06-2015, 04:24 PM
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Ahh, didnt bed the pads. I will go outside and do that now. Rotors are the same ones. Did not need to replace or resurface.
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Old 10-06-2015, 04:29 PM
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The resurface/crosshatch of the rotors "cuts" the pad surface during bedding.

No resurface=reduced brake performance.

The bedding process takes at least two 30 minute cycles (with a TOTAL cool down between them).

Part 1 (NOTE: DO NOT ALLOW ABS ACTIVATION)

a) Perform a series of 10 to 15 partial stops from 65 mph to 10 mph (preferred) with the first 3 under moderate braking, increasing to 75% to 90% of full braking during the series of stops. (Please ensure compliance with all applicable laws and ordinances.)
b) Performance should increase somewhat during this process and fall off toward the end of this cycle.
c) Do not come to a complete stop during this cycle, if at all possible, as this may interrupt the material transfer process to the rotor surface; Note: material transfer process will take longer with new rotors.
d) If friction smell becomes excessive during this first series of stops, become less aggressive with braking and complete the test sequence. Excessive braking at this stage can cause the resins to be released from the friction material leading to Green fade and coating of the rotor surfaces with excessive amounts of resin, which is undesirable, rather than a proper mix of friction material.
e) Allow the brakes to cool by driving at higher allowable speeds and with little if any braking, if possible.

Part 2
a) Repeat the above sequence, including the cooling section
b) Generally 2 complete sequences is often sufficient
c) A 3rd sequence may be performed if deemed necessary.
d) Allow brakes to cool, as per above, before coming to a complete stop or parking the vehicle

Notes: Pads driven primarily on street will require periodic more aggressive braking, to replenish/maintain the transfer layer of material on the rotor surface.Note: DO NOT ALLOW ABS ACTIVATION during the bedding procedure as this may result in a non-uniform transfer of friction material to the rotor surface and a reduction in braking smoothness. The rotor surface may require attention if this occurs. (e.g.ScotchBrite/BrakeKleen).
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Old 10-06-2015, 09:18 PM
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One thing that helps avoid a spongy brake pedal feel is to open the bleed plug when you press the piston back to allow for the new pads to fit. Pressing the content of the caliper back into the brake line is not great. I find that bleeding the old fluid out helps avoiding the soft pedal and while you are at it you can get an unsuspecting household member to press the brakes and flush the lines as well :-) (I have a catch bottle with a plastic hose to catch the old stuff and it is not pretty what comes out even after only one set of pads comes to its end.)
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Old 10-06-2015, 09:59 PM
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Quote:
Originally Posted by rlteee View Post
Rotors are the same ones. Did not need to replace or resurface.
Really?

What did they measure?
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Old 10-07-2015, 12:07 AM
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I forgot what it measured, but i believe it was 29.4mm.

BTW, i bed the pads earlier today and its back to normal. Thanks for all your help!
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Old 10-07-2015, 11:57 PM
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I'm shocked that did it. They probably still need to be bled.
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Old 10-08-2015, 12:34 AM
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Quote:
Originally Posted by absentmathis View Post
I'm shocked that did it. They probably still need to be bled.
100% of the time Ive replaced pads and not opened the hydraulic system they have never 'needed bleeding'.

New pads, worn rotors- it takes a bit of use or bedding to get the surface areas to mate. Common

IMO
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