Folks,

I tried searching this forum for information on brake pedal to master cylinder pushrod length and was unable to locate the answer to the following:

When converting from a power assisted disc/drum setup to a manual disc/drum setup, does anyone know the correct length for the pedal to master cylinder pushrod?

Thanks,
Bill

I think you need an extra 1 3/8" (1.375") in length. (or 1 3/8" less going to manual brakes.. I'm unsure.)

I had the same (or similar) problem to you and easily had an extension made.
http://forums.hotrod.com/ubbthreads/showflat.php?Cat=0&Number=151267&an=0&page=4#151267
Scroll down until you see this picture.
http://www.classicperform.com/TechBook/master_adapter.gif

Steve,

Thanks for that link. Excellent info. I might be overthinking this as I am going from an OEM power brake setup to an OEM manual brake setup . Should I simply require a shorter pushrod from an OEM manual brake master cylinder? If so, are they available through aftermarket or parts stores?

Thanks,
Bill

Folks,

Thanks to a ton of information on this site I was able to get to this point in making a decision on which components to purchase.

Would anyone like to take their best shot at advising on the correct combination of the following parts to convert from a power disc/drum combo to a manual disc/drum combo on a 69 big block car with the original J52 brake package? :

1351 master cylinder - Corvette non-power
1352 master cylinder - Corvette power assist

Y00076-LR master cylinder actuating rod, long - from drclassic.com
Y00076-BR master cylinder actuating rod, short - from drclassic.com
Y00168 manual push rod 67-69, adjustable - from drclassic.com

OEM prop valve + residual valve
Aftermarket prop valve

Also, why do the 2 masters I have looked at (1351 & 1352) do not have bleeder screws?

Any help would be appreciated.

Thanks,
Bill

Most of the aftermarket masters do not have the bleeders built in. Should not be a problem, but you will need to bench bleed the master before you install it

I would go with the manual master cylinder for two reasons: its is more likely to have the deep cup in the piston to hold the push rod in place, and the diameter will be smaller for a better pedal effort
I would look at David Pozzi's site for more information on the masters

and a long push rod, because you need it with the deep master

I don't know if you already have heard or read this, but you also need a brake pedal return spring. And you have to move the push rod to the upper hole in the brake pedal

Also, as long as you will still be using the same disc/drum brakes I would leave the proportioning and residual valves in place

Thank you.