brake help needed

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mattdus

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liverpool ny
I replaced my master cyl but I still have no pressure at the pedal. The rear bleed good but once I got to the front I could get little to nothing to come through. there are no leaks anywhere. once the rears were done the pedal would stop hard about 3 inches from the floor and the rear does seem to be grabbing some, but no matter how much I try to bleed the front I get no more than a drip or 2 of fluid and no pressure at the pedal. I have done brakes plenty of times but never had this happen. I am wondering if there could be a problem in the block the lines from the master go to (I assume this is some sort of pressure valve) but I am at a loss. Thanks for the help.
Matt
 
could have had a chunk of dirt drop in the end of the hard line or an internal failure of one of the soft front lines. That would be my guess.

(That or you got a junk MC which does happen but if it bench bled fine I think it's down stream from there)
 
if there is crud in the line would that keep the flow down as well as keep there from being any pressure? There was rusty crud in the rear bowl of the old master, but I figure that a blockage in the line would have still allowed some pressure build up. but then I am likely way wrong.
 
I have seen this happen when the pedal doesn't let the master cylinder pedal come back. Possible wrong piston in the cyl. or rod not installed correctly. This can be diagnosed easily by backing off the master cyl. attachment nuts about a 1/4 inch evenly and try bleeding it then. But first try this, reset your proportioning valve by pushing the button opposite of the brake failure warning switch on the proportioning valve. I forgot about this, try this first and then go to loosening the cyl. if this don't work . Good luck , Maybe a bad cyl.
 
Thanks guys I will see what happens in the morning.

"reset your proportioning valve" is this the block where the lines all meet down at the frame?
 
got them done today, turned out to have a small leak in one line but there was so much air in the system that you couldn't get fluid down to it to see it. Thanks for the input!
 
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