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Old 05-10-2012, 06:50 PM
Registered User
Join Date: May 2010
Posts: 64
201 brake pedal suddenly hard

Hi guys, today while driving i was approaching an intersection i applied brakes as per normal the pedal got really stiff, i almost pass out when that happened, luckily my reaction was to release the pedal and apply it again. this time the brakes worked as it should.Has anyone out there experienced this happening to them? and what caused it?how to prevent it from happening again. thanks for your input.

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Old 05-11-2012, 12:21 AM
280EZRider's Avatar
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Join Date: Jul 2007
Location: Medford, OR
Posts: 1,488
I don't know exactly what you are saying here, but if the fluid has moister in it, this could cause pitting and rust on the pistons and caliper seats. It's possible that enough rust or pitting caused one or more of the pistons to stick just this one time.

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Old 05-11-2012, 09:01 AM
teezer's Avatar
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Join Date: Sep 2007
Location: ohio
Posts: 159
in most cases where the pedal is hard with the engine running, it's related to the brake booster ~~~ look for a vacuum leak on the feed to the booster tank, or possible booster diaphragm tear, which is inside the booster tank

1989 300ce smoke silver / brazil, in a constant state of flux ~~~
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Old 05-11-2012, 10:51 AM
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Join Date: May 2010
Posts: 64
hard brakes

Thanks for your suggestion EZrider & Teezer.I replaced the brake booster in january and i know the gasket is good,for the brake caliper i replaced the left front with a used one as the original was frozen.Do you think the booster vacuum line could be the culprit then.more suggestions please.Thanks
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Old 05-14-2012, 02:08 AM
JamesDean's Avatar
Electrical Engineer
Join Date: Apr 2005
Location: NE Ohio
Posts: 5,034
As it was said previously, normally hard pedal = lack of vacuum. Perhaps you have a vacuum leak somewhere that come and goes?

Check on that replaced caliper, maybe it is giving you some issues.

When was the last time you flushed the brake system out?

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