brake help please

[dandsgcuda]

Hoefully someone can tell me whats wrong. My car had manual drum brakes all around and it worked fine.I changed it to manual disc up front a few weeks ago and now I can't get the brakes to work at all.I have pumped more than a quart of brake fluid thru them and still nothing. You can pump them 2 to 3 times and build a little pressure up and it will hold but as soon as you let off the pedal and reapply pressure it goes straight to the floor nothingat all. The master cylinder is off a mid 80"s truck or van with 1 1/8 bore and worked fine. I don't have the metering valve hooked up yet I just ordered it but they still should work so I can move the car.Any help would be much appreciated because I am to the point to get a "BFN" hammer and relive some frustrations 

[NoMope Greg]

If you've pumped a quart of brake fluid through the system, it seems to me that the first thing to figure out is where all that fluid has gone.  Have you checked the rears to see if you blew out a wheel cylinder?

[Bullitt-]

Someone once put the disk brake calipers on the wrong sides upside down....I won't say who, but the best I can figure is that if the bleeder is pointing down you would never get the air out.

Just a thought.

[wiging19]

Someone once put the disk brake calipers on the wrong sides upside down....I won't say who, but the best I can figure is that if the bleeder is pointing down you would never get the air out.

Just a thought.

How true, how true...

[Chryco Psycho]

once you get it bled out you may find the pedal is too hard & you need a smaller bore master to get the modulation right

[dandsgcuda]

the bleeder valves are on top and the reason I went thru over a quart of fluid was bleeding the system because I thought there was a traped air bubble in the calipers.there are no leaks anywhere and when I had the drums on the front the pedal pressure felt fine.It acts like like the master cylinder is not building any pressure and is just recirculting the fluid.I have put another master cylinder on and it acts the same way.Is there any way if brake warning switch(block)became plugged or malfunctioned that it would'nt allow the system build pressure and just bleed off .

[Chryco Psycho]

not really , the block could be plugged but it would still build pressure , there is nowhere for the fluid to recirculate either , did you bench bleed the master ?

[dandsgcuda]

 the master cylinder was bench bleed till there was no air bubbles.After you have pumped the pedal if you open the cap on the master cylinder you can here sucking sound like it some how created a vacuum.