I'm trying to get the brakes up and running on 69 Malibu with 4 wheel manual drums. I replaced front wheel cylinders, flex hoses and master cylinder. After bench bleeding MC and installing I started to bleed each wheel starting with right rear. Can't get no pressure, a few drops of fluid came out. Tried left rear, same thing. Meanwhile front wheel cylinders are pumped up and doing their thing when I pump the pedal. So I bled the right front wheel and can move plenty of fluid through there.

What is going on at the rear wheels? :confused: I even removed the MC and did the bench bleeding again. If I have the pedal push rod too far forward will that limit the pressure the rear reservoir of the MC can develop? My first try had the push rod adjusted way to the rear in the brake pedal so this doesn't make sense. Thanks for any ideas.

Dave

Having the rod too far forward shouldn't affect the rear brakes but the opposite since the MC "times" the hydraulic pulse to the rear to come on slightly after the front begins to work. Why? If you ever lock up the brakes, you want he fronts locking up first. If the rears lock up first the rear end will come around on you and that is very unstable and dangerous.

I had a similar problem when I rebuilt my '65. I was also using silicone fluid which at least in my experience was a little harder to push down that long front-to-rear pipe. Perhaps silicone fluid is slightly thicker? Anyway, the only way I ever got it down to the rears was to use my MytiVac pump to pull the fluid to the rear. This didn't completely bleed the brakes but once I had good fluid in the pipes to the rear I was able to bleed the brakes in the normal fashion.

But I was dealing with a completely dry system. From you description it sounds like you didn't touch the rear half of the system except for the master cylinder. If that's the case, I'd either again look at the master cylinder, I've taken back THREE of them to get the brakes right on my truck following a disc brake conversion, but even more so I'd check that the proportioning valve or front/rear balance block (whichever you used) is working properly and in the case of the proportioning value that it is set to the right level.

If you didn't install a prop valve or balancing valve that in itself could be the problem. Discs and drums work differently, discs take more fluid volume to move them, so your pedal push could be all gone before the rears get any pressure. Also, if you are using the standard balancing valve (nonadjustable), the cast iron block with an electrical connector, and it is really old chances are it isn't working properly. Replace it and you should be just fine. I fought the same thing on my truck for years before I figured it out.

If I put a hand pump on the one-way speed bleeder valve at the rear wheel cylinder can I suck fluid through the system at that point? Do I need to pump the pedal at the same time or will fluid just move through?

The fluid should move through when using a pump. You shouldn't have to pump the pedal while using the vacuum pump.