57 Chevy has no brakes!

[Maxwell007]

A lot of good info has been posted about your problem.  I would only suggest that you take a methodical approach to the problem.  I worked for a major brake manufacturer for over thirty years and while I get stumped from time to time, believe me.....I think I've seen it all.  So, for what it's worth, here's what I would do.
First, buy some brass plugs (flared style...not pipe plugs) and plug both ports on your master cylinder.  Then try pumping the brakes.  You should not be able to pump them.  If you can, you either have air in the master cylinder or it has an internal bypass usually caused by a bad seal.

Next, try the suggestion of pinching the hoses.  First, pinch them all and you should have much the same results as the above test.  The pedal should not move much if at all.  Then release the clamps one at a time, testing your pedal each time you remove a clamp.  When the pedal goes to the floor, you have found where your problem is.  

I believe you mentioned earlier that you had the line for the rear brake connected the rear port of the M/C.  In most systems, this is wrong.  The rear piston is the first one that "sees" pedal movement and is usually plumbed to the front brakes.  

Next, there was mention of a residual pressure valve.  Usually, this valve can be found behind the brass cone shaped fitting just inside the port on the M/C.  I looks like a little rubber plug but it has a slit cut in the face of it to allow most of the fluid to return to the M/C while keeping a small amount of pressure in your rear brake system.  (Usually about 5 PSI.)  As someone mentioned, if your M/C is for a four wheel disc car, odds are that it does not have this valve.  This could be part of your problem.

Lastly, I believe you said that the calipers were from an older Chevelle.  If so, I would not suspect that they are the cause of this.  But, if they are from a mid-eighties car, you may have "low drag calipers" which require a different type of M/C.  The low drag calipers were designed to pull the piston back further away from the rotor than older designs.  This was done for fuel economy reasons.  To compensate for this, the M/C used was called a "quick take up" master cylinder.  It had a two stage bore in it.  A larger bore in the back and a smaller bore toward the front.  You can visually see this when you look at the cylinder.  It is fatter toward the firewall end.  The idea was that the bigger piston in the back would move more fluild under less pressure.  This higher volume of fluid would move the calipers further and quicker.  When the pads came in contact with the rotors, pressure would build causing the pressure to transfer through a valve to the front (smaller bore) portion of the M/C.  From then on, braking would work just like the old design.
Sorry for the rambling explanation but I have seen "low drag" calipers put on cars with the old style cylinders and the results were much as you have described.  The small bore on the standard cylinder just can't move enough fluid to make the pads move far enough, quick enough before you run out of pedal.  You indicated that you think you have a lot of clearance between pads and rotors which would lead me to think that you may have low drag calipers...just a thought.  
I'll continue to watch this thread and perhaps I can send some photos if you would like.
Good luck!

[wayne petty]

Hello;
Wayne, if my calipers are moving more than a 1/16" what should I be looking for to correct this? The times I was bleeding, I am pretty sure that they were moving more than a 1/16!

Bruce

have somebody pump the brakes.. while you look at the calipers...

find out why they are moving more...

take them apart.. examine stuff..   see if there is a lump on the top center of the inside pad that is hitting the top of the piston... causing it to press only on that spot first..

here is a picture of the WRONG smaller brake pads...

http://contentinfo.autozone.com/znetcs/product-info/en/US/pfc/0154-20/image/8/

look at the left upper shoe.. there is a small dent that sticks out and locks into a groove in the seville rear caliper piston... stops it from spinning.. if these shoes got installed on the fronts..  the piston would press only on this and you would have the problem that you describe..

you need to see if the pads are sitting flat against the rotor and against the caliper...

it is quite possible that you have quick take up calipers like the new guy described..  but they worked before...  and the system failed with just a pad and wheel bearing change..

just curious.. how tough was it to retract the pistons???

i think you are going to have to take the caliper bolts back out of one side... examine everything..   make sure the caliper slides are free to slide and greased.. with white grease.. or sil glide..

just because the bolts will go through.. does not mean the caliper slides are free to move..