> Wally,
>
> I've been through your spreadsheet and I understand where all the numbers
> come from, having deciphered all your divisors. However, I don't
> understand the logic of the last two columns, I and J. The best I can
> figure, you're saying that there are 4 different input rods available
> (0.545" to 0.781" in diameter). And that the pedal pressure required to
> produce output is dependent upon the area of the selected input rod (and
> the mechanical advantage in the pedal)? Huh! Shows how much I know about
> Hydroboost! I had always figured that the pedal pressure merely overcame a
> spring load, independent of the PS pump pressure. Have I been that wrong
> all this time?
>
> I guess the reason for my confusion is my past experience with a Chevy P-30
> chassis motorhome which had what I thought were a variant on Hydroboost
> brakes. That coach had a really weird feeling brake pedal and the owner's
> manual recognized that. It had a statement to the effect that "...it's OK
> if the pedal goes all the way to the floor, you're still getting maximum
> braking...". And I had a panic incident that verified that statement with
> extremely good braking. Admittedly my current Hydroboost feels nothing
> like that one did.
>
> Ken
> Confused
> H.
>
>
> On Sat, May 27, 2017 at 7:05 PM, Wally Anderson
>
> > I've made a spreadsheet on Google sheets to show brake pressures available
> > from hydroboost conversions of factory vacuum assist brakes specific to our
> > GMC's. It shows pedal force, effects of different master cylinders and
> > variable pump pressure.
> >
https://docs.google.com/spreadsheets/d/1za2yNDR77iZDuC_
> > mNj9syVgZTOP1HXGSpbT4vrS5xIw/edit?usp=sharing
> >
https://docs.google.com/spreadsheets/d/1za2yNDR77iZDuC_
> > mNj9syVgZTOP1HXGSpbT4vrS5xIw/edit?usp=sharing
> > --
> > Wally Anderson
> > Omaha NE
> > 75 Glenbrook
> > Megasquirt III injection
> > Bob Stone hydroBOOOOST
> > Manny reaction arm system
> > Branscombe Kelsey Hayes park brake
> >
http://wallyandsue.blogspot.com/
> >
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Ken, You got it. The whole hydroboost case is pressurized in operation so it pushes back on the input rod.
--
Wally Anderson
Omaha NE
75 Glenbrook
Megasquirt III injection
Bob Stone hydroBOOOOST
Manny reaction arm system
Branscombe Kelsey Hayes park brake
http://wallyandsue.blogspot.com/
