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Old 08-18-2014, 11:24 PM   #1
vision.dynamix
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Default Brakes feel like pudding after Brembo Swap

Did a Brembo swap in an 03 WRX Wagon. Did new lines and fluid.

Bled them today, and after going around twice with a Motive Power Bleeder, the pedal felt like stepping into Jell-O. It took many pumps to get it to "firm", but it was never hard as a brake pedal should with the engine off.

Manually bled it, no difference.

Let it sit for an hour, power bled it again, and it was marginally better. If I pump the pedal, itll eventually get firm. But if I take my foot off the pedal, 3 seconds later, itll go all the way to the floor again and I'll need to pump it again.

Driving it, the first step of the pedal is complete rubbish and does nothing to stop the car. A quick second step will provide some pressure and stop the car.

Any ideas?
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Old 08-19-2014, 02:11 PM   #2
mrsaturn7085
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The STI uses a 1-1/16" master cylinder... I'm pretty sure the 03 WRX used the same, but do you know this for sure? If it's a 1" cylinder, this could be part of it.

Sounds to me like you either have air in the ABS module, or more likely, you destroyed the master cylinder seals when you bled it. Did you put the brake pedal to the floor while manually bleeding?

Did you run the master cylinder low at any point of the caliper replacement? If so, you may need to bench bleed the master cylinder.
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Old 08-19-2014, 02:54 PM   #3
mitch808
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MC size will have no bearing on the pedal going to the floor. You can either have more pedal effort or less pedal effort, but brakes would work the same.

Air is in the system, or there is a leak in a seal like within the MC's piston.

See if you can get the ABS system to cycle on some loose gravely road a few times.. Then bleed again.

Worse comes to worse, do the MC bench bleed.
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Old 08-19-2014, 04:17 PM   #4
mrsaturn7085
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Quote:
Originally Posted by mitch808 View Post
MC size will have no bearing on the pedal going to the floor. You can either have more pedal effort or less pedal effort, but brakes would work the same.
Good point - this would only matter in a pad knock-back situation.

Quote:
Originally Posted by mitch808 View Post
Air is in the system, or there is a leak in a seal like within the MC's piston.

See if you can get the ABS system to cycle on some loose gravely road a few times.. Then bleed again.

Worse comes to worse, do the MC bench bleed.
My money is on air in the ABS - the MC seal is *usually* the culprit, but since you didn't manually bleed the brakes prior to the problem occurring, you didn't have a very good opportunity to damage the seals by mistake.
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Old 08-19-2014, 04:30 PM   #5
vision.dynamix
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MC was never run dry, and the system was power bled before testing. It was only then did we switch to manual bleeding, and I made sure to not completely bottom out the pedal.
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Old 08-19-2014, 04:31 PM   #6
vision.dynamix
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How do I get air out of the ABS?
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Old 08-19-2014, 04:36 PM   #7
fastnoypi
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Quote:
Originally Posted by vision.dynamix View Post
How do I get air out of the ABS?
check out this thread http://forums.nasioc.com/forums/show...2#post38959812

you have to short out pins 3 and 6, then rebleed
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Old 08-19-2014, 04:48 PM   #8
vision.dynamix
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Cool. Will try that. Can I keep using the power bleeder?
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Old 08-19-2014, 04:59 PM   #9
fastnoypi
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i dont see how using a power bleeder can mess up the process. I'd give it a try, good luck!
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Old 08-19-2014, 08:13 PM   #10
JonnyV2889
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Mmmm. Brake pudding, my favorite. Seems like you've got a good handle on the situation.
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Old 08-21-2014, 11:47 PM   #11
Blingstrom
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Did you bleed from both bleeders? Probably a dumb question but after replacing lines on an evo I just used the outside bleeder. Pumping the brakes twice it was fine otherwise it was not good. Does sounds like you just have some air stuck but possibly have solved it by now.
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