Hi all, I've got a few questions regarding my brake system. It appears to be stock, but it has been off the car for years now during my resto. I'm about the install the brakes again and before doing that I'm inspecting my hardware. I have the 5468309 EA master cylinder, which strangely has the 1970 code = 1 1/8". And mounted next to it the hold off valve. 1 - how to remove the master cylinder from the bore? I removed the screw, I can press the piston, but it won't pop out. Has anyone some tips or tricks? Edit: compressed air did it. 2 - hold off valve - If I understand correctly it should block the outlet at first to open only with a certain pressure. I think that means mine was stuck in the open position, because I could blow air through it. I had to use the vice to press the valve on the back which is stuck now and closes off now. Edit2: I just found this snippet in the manual, which confuses me. To me, "depressing" means pushing. But if you depress it, you close the valve. Makes no sense to me. Did I just break my own valve in the vice? 3 - what is wise to do? I've seen some posts to replace the hardware with the newer combination valve, or can we open the hold off valve as well to try to repair? It does have a nut on it. Edit2: the manual states it's not reparable.
This forum is brilliant; I just stumbled on this thread: https://www.v8buick.com/index.php?threads/1967-1969-a-body-metering-valve-rebuild-kit.254762/ where a website for a Metering Valve Rebuild kit is mentioned, including a how to. So despite the manual stating it is not reparable, it apparently is I've disassembled mine in the meantime, so I'll rebuild it and then I won't be needing a combination valve. Now I also understand how the pressing would help with bleeding.
