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Old 05-16-2007, 02:47 PM   #1
massdaguy
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Default Brake pedal too low after changing pads

When I first purchased my 3i, I found the brake pedal higher (in compressed positon) than the gas pedal and felt very firm, a bit too high for the street I found, but probaby fine for the track to do proper heel and toe. Recently after changing to a set of Carbotech pads front and back (the stock pads were too sensitive when cold or at low speeds), I noticed that the brake pedal is now about 1/2" lower (when compressed) than the gas pedal, plus it feels spongy. This makes it very difficult to heel & toe. The brake system has already been bled twice (1st time with new fluid change to ATE Blue), with no change. I am thinking there might still be some air in the system that the normal bleeding process did not remove. Is there a better way to bleed out the hydraulic system other than the traditional method? My car has ABS.


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Old 05-16-2007, 04:02 PM   #2
everett-m3s
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Default Re: Brake pedal too low after changing pads

Get a friend, youll need to bleed more.

Top off the brake fluid resivior with brake fluid, and start pumping the brake like 10-15 times. Then, hold your pedal in, and have your friend (or vice versa, you bleed, they pump the brake pedal) bleed the line. Then, keep the pedal to the floor until he hollars back that the bleeding nut is back tight again, and repeat. I like to do this about 4 times per wheel.


After every wheel, check the resivior and refill brake fluid as necessary.


And also, remember start with the Passenger rear, then driver rear brake....then move to passenger front, then driver front. After each wheel, refill the brake fluid resivior.
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Old 05-16-2007, 04:12 PM   #3
j-so
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Default Re: Brake pedal too low after changing pads

Yup, sounds like you just need to bleed it better.
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Old 05-16-2007, 05:24 PM   #4
massdaguy
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Default Re: Brake pedal too low after changing pads

[quote author=everett-m3s link=topic=77682.msg1415440#msg1415440 date=1179345753]
And also, remember start with the Passenger rear, then driver rear brake....then move to passenger front, then driver front. After each wheel, refill the brake fluid resivior.
[/quote]

Is there any particular reason why the wheels have to be bled in this order? I thought the wheel hydraulics were connected diagonally.
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Old 05-17-2007, 09:04 AM   #5
j-so
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Default Re: Brake pedal too low after changing pads

Actually, shouldn't it be driver rear, pass. rear, pass. front, driver rear, then clutch(if needed).

There is a reason for the sequence, you start with the longest line and go to the shortest. If you didn't follow the proper sequence then you definitely need to bleed the brakes again.
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Old 05-17-2007, 11:11 AM   #6
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Default Re: Brake pedal too low after changing pads

[quote author=j-so link=topic=77682.msg1417204#msg1417204 date=1179407053]
Actually, shouldn't it be driver rear, pass. rear, pass. front, driver rear, then clutch(if needed).

There is a reason for the sequence, you start with the longest line and go to the shortest. If you didn't follow the proper sequence then you definitely need to bleed the brakes again.
[/quote]

Yes, bleed longest line first and shortest line last ( passenger rear, driver's rear, passenger front, driver's front ). Usually length is determined by distance from the master cylinder to the caliper. Since the master cylinder is mounted on the firewall (driver side), the longest line is usually the passenger rear. So start with that caliper first.
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Old 05-17-2007, 12:03 PM   #7
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Default Re: Brake pedal too low after changing pads

Hmm, I seem to be having the same problem... except my pedal compresses earlier than yours currently but later than when I had my OEM pads in. I also had my rotors cut/turned, so I'm not sure if that has to do with anything.. Maybe I should have my brake system bleeded? No ABS... (Edit - I just changed out the rear pads)
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Old 05-17-2007, 02:00 PM   #8
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Default Re: Brake pedal too low after changing pads

[quote author=BoostThat3 link=topic=77682.msg1417615#msg1417615 date=1179417804]
Hmm, I seem to be having the same problem... except my pedal compresses earlier than yours currently but later than when I had my OEM pads in. I also had my rotors cut/turned, so I'm not sure if that has to do with anything.. Maybe I should have my brake system bleeded? No ABS... (Edit - I just changed out the rear pads)
[/quote]

I did not get my rotors turned. My car only had about 2500 miles on the odometer at the time.
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