New Brakes, no Fluid to Rear.....What is going on?

Just installed a complete new brake system on a 66 CB-Body car, New lines, front disc brakes from a 73 C-Body, new rear drums and wheel cylinders, all new hoses etc. I converted the single res. master cylinder to a dual res. manual Disc/drum res. master cylinder. When I hit the brake pedal I am getting fluid to the front calipers but nothing to the rear. I am using the push rod from the single master cylinder from the brake pedal to the new master. Also, when I open a bleeder valve the pedal never drops all the way to the floor, but does go down further than normal. I am using the original distribution block for the front brakes and an adjustable valve (the black ones) for the rear brakes, I have tried it adjusting it in both directions but still no help. Any suggestions?

http://www.piratejack.net/Tech-Support/Ten-Reasons-For-A-Poor-Brake-Pedal.html

Read more at this site.

I just went through this on my '73 Roadrunner, when trying the bleed the back brakes there was nothing coming out, not even air. The fronts bled fine. It ended up being my proportioning valve was rusted solid, the piston was not moving. I put a (known) good used one in, and they are fine now, they bled the first time.

Thanks for hte input, I just discovered the problem but not sure on the fix. The front reservoir (back brakes) is not pushing fluid out, but it did during bench bleeding (new MC). It acts as if the push rod is not going in far enough, the return spring under the dash is completely squished down (for lack of a better word) but it is not pushing fluid out and with the bleeders open will not go to the floor. This is hte push rod from the single res. MC, is there a difference? I thought they were all the same, is the spring retainer location different on these? Do I need to either find a later C-Body push rod or order an adjustable one from Summit?

Any Help is appreciated.

Thanks,

Any Luck with this yet?

dude, 4BBodies is probably totally right. barring a blockage or gremlins, it's your metering valve. not only can a frozen plunger do it, but there are a series of rubber o-rings inside, if one has been distorted or torn, fluid will leak past when you press the pedal, the plunger will move into rear brake failure position (in your case), lock the line to the rear and you'll have front brakes only which will also result in that incomplete pedal depression you are describing. SO, unless you're in the mood for a poor man's line lock and or a lot of continued head-scratching, get a new metering valve. Service replacements are still available that look identical to originals minus part numbers, I'd tell you where I got my last one but my reciepts and stuff are on a different continent.

I do not believe the problem lies in your pushrod, I am fairly certain they are the same. If it was a little too short you would still get SOME fluid out of the system from either the front or the rear when you pressed the pedal, the depth of travel doesn't make a difference in the pumping of fluid to either half of the system, if it did you would have uneven braking and lose control.

the metering valve is not a bad part to replace anyhow as none of this old crap (said with love) has an infinite life span and brakes are moderately important.
Good Luck!
-Andy

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dude, 4BBodies is probably totally right. barring a blockage or gremlins, it's your metering valve. not only can a frozen plunger do it, but there are a series of rubber o-rings inside, if one has been distorted or torn, fluid will leak past when you press the pedal, the plunger will move into rear brake failure position (in your case), lock the line to the rear and you'll have front brakes only which will also result in that incomplete pedal depression you are describing. SO, unless you're in the mood for a poor man's line lock and or a lot of continued head-scratching, get a new metering valve. Service replacements are still available that look identical to originals minus part numbers, I'd tell you where I got my last one but my reciepts and stuff are on a different continent.

I do not believe the problem lies in your pushrod, I am fairly certain they are the same. If it was a little too short you would still get SOME fluid out of the system from either the front or the rear when you pressed the pedal, the depth of travel doesn't make a difference in the pumping of fluid to either half of the system, if it did you would have uneven braking and lose control.

the metering valve is not a bad part to replace anyhow as none of this old crap (said with love) has an infinite life span and brakes are moderately important.
Good Luck!
-Andy

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Thanks for the information, I really appreciate everyones input. I tried removing the brake line that goes to the Master Cylinder that feeds the rear brake lines, pumped the pedal and still did not get anything out, at the Master Cylinder. This method takes the Proportioning valve out of the equation. Everything on this system is new, lines, MC, Disc Brakes, Calipers, Wheel Cylinder, Hoses etc. With the Brake line removed at the MC, I assume I should be getting brake fluid out at the outlet on the MC.