[urq] Spongy Brake Pedal

[Ado Sigal]

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>>Guys,
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>>I am having trouble correcting a spongy brake pedal that does finally does
>>finally firm up and grab, albeit close to the floor.  The calipers,
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>rotors,
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>>pads, hoses and lines have been replaced.  I am using ATE Blue fluid, and
>>the master cylinder and lines have been bled twice.  Rear calipers have
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>been
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>>adjusted with the foot on pedal/ratcheting ebrake method.  The pedal gains
>>significant resistance after this adjustment, but when the car is driven,
>>the pedal becomes spongy again.  My first thoughts were master cylinder,
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>but
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>>my understanding is that the pedal would not become firm before hitting
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>the
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>>floor if this was the case.
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>>Any BTDT please?
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>>TIA,
>>Jim
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As a guideline, without bomb assistabce the pedal goes hard, so it isn't 
the bomb, but bleed the system without assistance and find the state of 
the bomb by the number of depressions, and the oil state and level at 
same time. If you can't acieve rock solid pedal at all, then it could be 
the MC, if the bleeding is difficult but you can acieve solid pedal 
initially which later becomes soft, then the proportioning valve could 
be the culprit.

HTH,

Ado