No brake fluid to front brakes.

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68 tuna can

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Good evening everyone! Just going g to bleed brakes on the tuna can and ran into an issue.. I have no brake fluid getting to the front wheel cylinders. Wheel ends are all new including wheel cylinders, shoes, drums, etc. Every single brake line and hose has been replaced as well. Only thing original is the master cylinder and junction block. The master did leak whe. I bled it (sat for 3 years dry), I took it apart cleaned out the gunk and reassembled. Seems OK now but.... any thought from the great minds in this forum? Could it be the junction valve? I cleaned and blew it out before reinstalling.. again everything is new. Pedal feels solid with 2 pumps. Back brakes are good... getting cranky in Toon town

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Just keep pumping till something comes out, only opening the bleeder when the pedal is down.

Or... let gravity do the work. Cap off the master, bleeder screws open and let it dribble.
This may take a lot of time.
 
Did you bench bleed the master cyl?

If not you probably have a ton of air in the lines.

You can bench bleed the master on the car.

  1. Raise the rear so the master is level.
  2. Disconnect the lines from the master
  3. Make two lines to go from the master output back into the reservoir
  4. Fill the reservoir and slowly depress the brake pedal and slowly return it.(A helper would be good here)
  5. After no more bubbles come out, remove the lines, and put the other lines back on.
  6. Bleed as normal
 
I did bench bleed it on the car, then on the bench after taking it apart and cleaning it out. Both sides pushed fluid well... I. Starting to think the junction valve pooped the bed somehow. For the time it takes to recheck the master I will re bleed to be sure. Brakes worked 3 years ago before car came apart for rebuild lol.
 
loosen the adjustment rod upon the booster . your master is probably not coming back all the way to let fluid in the passage
 
If the front brakes are drums, & the residual line pressure valve is still being used, then you cannot gravity bleed these.
 
Does your distribution block have a safety valve in it? The sliding valve must be centered to allow flow to the front and the back.
 
Really trying to save that M/C on that beautiul car.
Even if it did start to work, I would not trust my life or my car to it.
Don't rebuild it. Replace with new.
Flush entire system with new bottle of quality fluid.
Enjoy.
 
Did you check to see if the master cylinder piston is coming back all the way so the rear piston chamber is getting fluid. Check to see if you have fluid pressure at the rear port on the master cylinder. If you don't? Loosen the master cylinder as much as you can so it pushes away from the booster. This will let the piston come back all the way so you get fluid to push. If this corrects the problem take the master off and adjust the push rod shorter . I have seen this many times to be the problem

As far getting a master. Check the Cast number. Rebuild yours or at least keep it if its original, If you don't use it I am sure someone on this site will grab it to get an original for their car. The original mopar master cylinders are getting hard to find.

http://www.moparts.org/Tech/MoparAction/Master_Cylinder.pdf
 
If you didn't put the m/c back together correctly, depending on style, one very thin washer in the wrong place can cause no pressure.
Just saying
Good luck
 
So in the end one of the new lines I installed had a blockage on one end!! I had to use a drill bit to clear it ( was like cement), once reinstalled, I had fluid to the front brakes. Everything is working as it should.. I think I am going to replace the Master cylinder anyways as it is the only remaining original part... thanks everyone for the comments and help on this

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Glad you got it figured out. That's really odd. Makes me wonder what else might be lurking in those lines.
 
Oldmanmopar said:
Did you check to see if the master cylinder piston is coming back all the way so the rear piston chamber is getting fluid. Check to see if you have fluid pressure at the rear port on the master cylinder. If you don't? Loosen the master cylinder as much as you can so it pushes away from the booster. This will let the piston come back all the way so you get fluid to push. If this corrects the problem take the master off and adjust the push rod shorter . I have seen this many times to be the problem

As far getting a master. Check the Cast number. Rebuild yours or at least keep it if its original, If you don't use it I am sure someone on this site will grab it to get an original for their car. The original mopar master cylinders are getting hard to find.

http://www.moparts.org/Tech/MoparAction/Master_Cylinder.pdf
Click to expand...
Thanks ESP47... well documented.ented article.. well worth having around!
 
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