Original to what? I'm guessing 1964
In that case there is no shuttle, so you got it right as far as can figure.
I which case, Ima thinking that the chamber between the Power pistons does not have fluid in it. Lemmee think
Yeah I think that's it. See bold below.
Do you understand what I'm talking about? If not, I'll go dig up a picture to illustrate. say the Word, I'm retired. I got lotsa time, especially now that I'm only needing like 4 hours of sleep every night, lol.
Did you bench bleed the Master?
Ok/ok, I got time; Here's an image.
Notice that the two pistons have a chamber between them which discharges into the front reservoir . That M/C cannot work unless that chamber is full of brake fluid, because the pistons are NOT otherwise coupled. Instead, they are hydraulically coupled. Well, they are supposed to be, lol. So how then do you get fluid into there?
Notice the power pistons are yellow.
Notice the RH piston has an extension on it that touches nothing. The chamber to the left of it has to be full of fluid to transmit the pedal movement hydraulically from the RH piston to the LH piston, which then operates the second half of the dual system.
If there is no fluid in that chamber, then extra pedal-travel (built into the system), will be needed, to bring that formerly thought to be useless extension on the RH piston, into physical contact with the LH piston, and now they are mechanically coupled and the brakes should all work, allbeit with a low pedal.
However, the compensating port of the RH chamber can no longer work! so long term, that RH chamber will fail to function.
Furthermore;
If that chamber is empty, the RH piston will slide right on by the discharge port to the front brakes, until it meets resistance in the LH chamber ! and I think this is what's happening to you.
So , how do you get fluid into that chamber?
Well normally, we bench bleed the M/C, which involves clamping the M/C in a vice, at a slight angle, up at the front, to ensure that air will leave the power chambers. Then we install little rubber/plastic lines from the outlet ports up over the sides of the reservoirs and submerging them in the fluid. Then we just FULL-stroke the piston package until all the air has left the system. Simultaneously, we watch that the C-ports are purging, and, when the bubbling stops, voila, we are done. Clamp the rubber lines, secure the cap, and reinstall it.
Hold on bubba;
Sometimes it happens that air leaving the pistons via the return hoses, does not travel all the way around and back into the reservoir. Instead, it and possibly a small packet of fluid, just shuttles back and forth inside the hoses, and so you think that you're done, but you're wrong; you just don't know it, cuz you cannot see it. This is why I use clear plastic lines, so I can catch that shameful action.
To stop this from happening, I just pinch the hoses near the reservoir ends, with my free hand, on the back stroke. This creates a low pressure in the hoses and forces the fluid in the reservoirs, to be drawn in thru the tiny C-ports. and ....... NOW, yur done.
Since, to bleed the M/C, the front end has to be higher, you might think to do this with the M/C installed in the car, and one could, so long as the Power-piston package fully strokes in both directions, and the air leaves. But-um, how can you know that the air has left? If the hard lines are installed, you can never be sure. Maybe, the fluid is just shuttling back and forth as described above. Sure, you could crack the lines, but that's gonna make a mess and brake fluid eats paint. So, just don't do it!
Now, after that power chamber is full of fluid, and the lines are full, then the M/C can be reinstalled, and the hard lines hooked up..
After that the system is bled and working, you still have to prove that the pushrod is adjusted to the right length. The Pushrod has to pull the Power-Piston assembly towards the firewall, to it's designed parking spot, to always allow the returning-fluid, to enter into those chambers around both pistons, and thence to return into the reservoirs, thru the ports. On every pedal stroke, the first inch or so of stroke, is used up, in pushing the pistons past those C-ports. Those ports are called compensating ports, because as your friction materials wear, if they were not there, your pedal would sink ever closer to the floor until one day, the car will fail to stop. So, those ports, compensate for friction-material wear, and they have to always be open with the pedal at rest, against it's up-stop.
Sorry about the delayed answer; we had an electrical power outage so I grabbed a couple of hours sleep.
Ok, so I'm just gonna proofread this, and edit as may be required and in an hour, it's all yours.
OK/DONE! let the questions fly!
