[mchell]

Originally Posted by Scarebird

it is 1.125" - too big for manual.

mchell: what car is this going on?

68-72 gm abody

[Scarebird]

ahh.

I am using a 1974-80 GMC 1/2 ton manual master. It comes with a push rod that you can simply thread for your clevis. Use you pedal but the upper hole. Move your stop switch bracket up.

https://www.rockauto.com/en/moreinfo...t=1836&jsn=485

[FrankieT/A]

When I was younger I always hated hydro boost. They were in trucks, Eldo's, Seville's, etc. Leakage and weird pedal.
30 years later I put it in my 71 Trans Am and absolutely love 'em. Put the system together myself for under $250 with all brand new parts except the unit itself. I won't look back...

[Formulajones]

Originally Posted by FrankieT/A

When I was younger I always hated hydro boost. They were in trucks, Eldo's, Seville's, etc. Leakage and weird pedal.
30 years later I put it in my 71 Trans Am and absolutely love 'em. Put the system together myself for under $250 with all brand new parts except the unit itself. I won't look back...

My 79 Chevy 1 ton had factory hydroboost. Owned that truck for about 25 years, several cross country trips pulling trailers, it never let me down, loved the brakes. I never had to touch the hydroboost system on that truck. Even on a truck with front disc and rear drum that scaled 5300 lbs that thing would stop on a dime.

Adapting them to a car to me is the ultimate if you want stopping power.

[FrankieT/A]

Originally Posted by Formulajones

Adapting them to a car to me is the ultimate if you want stopping power.

1000 percent

[GOAT8U2]

Chart of brake booster size and psi to give you an idea of what happens when you move away from the 11". Problem is the Chart doesn't have the 9" dual but from my memory, it's awfully close to the 11".

I have 1 1/8 master but that was due to having 4 wheel disc brakes with 4 piston calipers, it wasn't just about pressure. The volume you need to feed those 4 big boys matters too so gotta have both on certain setups.

[Scarebird]

I am not so sure about that chart...

[Vid]

I had manual drum brakes on my 67 wagon and although most guys wrinkled their noses and suggested I upgrade, I never had a problem with the system or any trouble stopping when I needed to. It’s a viable option as far as I’m concerned.


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[AG]

I have a friend that put a hydroboost system in his 1971 Vette with a healthy 427 SB that makes 8" of vacuum and it works great. Personally, I don't like them because of all the extra components/lines and I don't like power brakes for anything other than keeping your car 100% stock. I prefer manual front disc brakes for the clean look of the engine bay.

[Formulajones]

It takes only a little extra effort to hide things. I run the lines under the unit and then immediately behind the fender. The lines then come out from behind the headlight down by the frame where they go directly to the box and pump.

This requires longer lines and some different fittings so I can direct the lines where I want, so I spend a little more money on the deal but when it's finished, it's clean. In fact at first glance it just looks like it has a manual master cylinder on it.

On the Chevelle for instance, behind the driver headlight there is the washer bottle and the charcoal cannister mounted there, so you can't even see the lines running out from behind the fender over to the box.

That's how I like to do them because just like mentioned, I really don't like seeing the lines just laying on the inner fender.