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2010 DTS
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Have you pumped the pedal a few times? Usually, after changing the pads (and thus compressing the piston), the first brake application will go to the floor. A second or third application should bring it back to normal.

If that doesn't help, and there are no external leaks, you might be looking at a bad master cylinder. That said, it's hard to imagine it would fail so completely and at just the same time as a brake pad change.
 

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Discussion Starter #3
Have you pumped the pedal a few times? Usually, after changing the pads (and thus compressing the piston), the first brake application will go to the floor. A second or third application should bring it back to normal.

If that doesn't help, and there are no external leaks, you might be looking at a bad master cylinder. That said, it's hard to imagine it would fail so completely and at just the same time as a brake pad change.
I did pump several times, plus used a bleeder pump to bleed them. I just ordered a master cylinder. Has to be that because there are no leaks.
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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20,098 Posts
actually - it is NOT that unusual -
after replacing front pads - the first time you apply the brakes the pedal CAN go all the way to the floor -
and THIS is what CAUSES the master to fail -

the "O" rings travel past the ridge that is formed over the years of "normal" pedal travel -
this destroys the "O" rings and you end up with internal leaks and no pedal -

I ALWAYS recommend using several very short - gentle pedal applications to pump the brakes up -
rather than one big push to the floor - just for this reason -

be sure to "bench bleed" the new master thoroughly -
once installed - you'll never get trapped air out of the master -
 
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