Kent,
Yes, when I ordered the replacement Master Brake Cylinder, it did not have the hole in the side for a third line (one line for the clutch, one going to the Hydrovac, and this one....I think it is a return from the Hydrovac, but I need to double check that). So, I took it to a machine shop to have it drilled and tapped.....and the mechanic laughed and said that he just did one for another guy last month who was restoring an old Chevy Viking firetruck.
(I just checked my shop manual for the 11" MultiVac brake unit, and the third line is indeed a return line from the Hydrovac.....seems this system has fluid going in, and fluid coming back to the MBC when the brake is released).
When I take the top off the MBC and gently hit the brake pedal, fluid squirts upward and it may be coming from this third line.....but I am not sure yet.
Yes, I was thinking that the Hydrovac could be full of brake fluid, causing problems. Guess I could open the bleeder and see how much comes out.
My shop manual does not say how much fluid (mineral oil) is supposed to be in the Hydrovac....so, I need to search around and get that info.
I will tackle the brake lines again and try to determine why the fluid is not making it to the hydrovac......either a collapse in that short rubber line, or the new MBC is not pumping.
Thanks for the input.
