hard brake pedal and cant get the back brakes to bleed.

I have no back brakes on my 71 dart.non brake booster car.I got one of those brake vacuum bleeder kits.still couldnt no fluid to come out of bleeder.tried havin someone pump the brake pedal still nothing.the brake pedal is very stiff i have a new brake master cylinder on and lines.what could it be?

did you bleed the master before install? is it a disc or drum brake car? there are different masters for them one has a larger piston and one is smaller on manual brakes the diference will affect pedal feel. i have also have blocked lines and distribution blocks before.

First thing is are you getting pressure out of both master cylinder ports? If you are then work your way from there back to the rear brakes to see where the stoppage is. If not be sure the rod from the pedal to the MC is adjusted right. Has this always been a manual brake car?

I had a shop put in while it was gettin painted,redid lines to.car was always a manual brake car.disc in front and drum in rear.

Seems if the shop put it in then they should make it work correctly.

Definitely right on that,they didn't.though they just needed to bleed.seems to be more than that now.

Like I said start at the master cylinder and work your way back.

sounds like the safety shuttle is tripped.

replace the rear center hose attached to the rear end

Before you replace anything I would crack fittings and see if you have flow. Either work from teh MC back or from the rear brakes forward, you will need a helper to work the pedal.

his first post eluded to cracking the fittings, unless i didnt read correctly.

My car has seemingly had this same issue. For my car, it was the rubber hose that fed the rear axle that had collapsed internally and needed replaced.

Rick

When I bought my 69 cuda I replaced the master cylinder, wheel cylinders (swapped the 7 1/4 rear for a 8 3/4). I bleed the front just fine, but could not get the back bleed. I tried the hand pumps, someone pumping the pedal etc. It ended up being the hose that connects to the rear.

I cracked the bleeders open and nothing from each one.brake pedal is so dam stiff u could hardly pump it.

If your talkin about the black rubber one,its been replaced.

New doesn't always mean that it's good.

As has been stated, start at the back and crack the lines loose and work your way forward to a point that you get fluid coming out.

It's either a blockage or a brake valve problem.

the bleeders are at the end of the line. You have the connection where the hose connects tot eh body hard line. crack it there and see if you get anything. If not, the hard line connects tot eh combination valve, crack the fitting there and see if you get anything. The combination valve is fed from the M/C, crack the fitting there and see if you get anything.

the problem will lay between the first leaking connection and the last one that didn't leak. If nothing comes out of the M/C that is your issue.

Get a helper and start bleeding brake lines.Start at the master and work from there.When you stop getting fluid flow,you found the problem.

As said; grab a helper to work the pedal & you starting at the MC.

If you don't have a helper I have found these and a little catch can to be perfect for doing it alone.

http://www.russellperformance.com/mc/speed-bleeders/

I had a time where the front brakes worked so well that it didnt allow enough pedal travel to push the fluid to the rear.

what you had was a misadjusted master cylinder pushrod or bad mc. The situation you described should not happen.

I had the same type of issue on a rebuilt mc from advanced auto. There are two Pistons separated inside by a spring. The spring keeps the spacing between the Pistons the correct distance, but with mine the Pistons were chewed up and would stick and not allow the spring to correct the spacing. So it would just block one port and allow no pressure out. Felt just like you put plugs in the ports. ROCK hard.

Well got i no fluid what so ever goin to back of car.i started at m/c took lines off there and pump the pedal and fluid was squirtin out of both ports on master cylinder.unscrew the line that goes to back to supply fluid and nothing.

I reiterate

And I agree with the reiteration................

How do you fix that?

For 71 the FSM says to replace the valve. 73 and later have an external plunger nub you can reset it with.

I would take it apart, clean it recenter it and reseal it.

I suppose you could pull the switch and try to recenter the shuttle thru that port.

with the valve been shifted over to the low psi side, with that corrected iirc there was something about slightly opening the high side making it now the low side & bumping the pedal to shift the valve back the other way to center it. Not sure how holding the "pin" valve open plays out with this procedure but others will clarify. I always thought the center valve was strickly an electrical on/off switch (to warn you of a leak on the "low" side) but did not shutoff flow so I learned something on this.

Kinda why I would start at the master.
1st, being you didn't install it, are you sure it is the proper unit?

I believe to reset the valve the electrical switch must be removed.Open a bleeder on the brake circuit that works and have someone push the pedal down.If the shuffle valve is not jammed or or stuck that should re-center the valve.Install the switch and everything should bleed normally.

^^^ noted

If you know to read thats what I did.

I notice fluid was leakin where the safety trip is.i tried to spray brake cleaner on of the rear ports of portioning valve to see if it would shoot out to the oher side of rear portioning valve hole it didnt.looks like its clogged or jammed up.

Are the inline tube portioning valves any good? I ended up orderin one form them.

Never used their stuff.

I always grabbed one out of a Diplomat, just match the rear drum sizing.

That combination valve is fairly easy to re-seal. I've since ditched it but if I recall correctly, just a teflon and a couple of o-rings I sourced from a hydraulic shop. Off the shelf stuff, at least in the 90's. As long as the housing and shuttle aren't dinged or pitted...

I need to re-set my prop valve i believe..How did you go about doing this? I 'think' its not letting fluid to the rears..

Just thinking out loud & someone may clarify better if this ain't right. I would crack the line slightly (a bit downstream from the prop valve) on the side that was not opened/leaking & pump the pedal (fast/brief) (till the light goes out) to shift the valve back the other way to centered.