need advice on power brakes

ENTDOC · #1 (**permalink**) 10-16-2003, 07:22 PM

I am using a 7" street rod booster with an aluminum master from a GM midsize car( 7 inches long) with 87 corvette disks on all four corners and my brakes stink!I have good pedal travel and I feel they are bled adequetly so I think the booster or master is the problem.Problem is I only have limited space, both length wise and diameter.Do you have any suggestions on options?I would like to keep power brakes but need a compact 4 disk setup. thanks;chuck

vettestr · #2 (**permalink**) 10-16-2003, 09:44 PM

I used the system from a Buick Grand National. It is a Hyd. pump driven by an electric motor and stores 2200 psi in an accumulator for assist pressure. Whole thing is about size of shoe box and I remote mounted in well by rear differential pumpkin. Powered a slave cyl. with the existing brake master cyl. to accuate my remote system. Cost about 200.bucks and WORKS GREAT!

Excaliber · #3 (**permalink**) 10-16-2003, 10:51 PM

,,commonly referred to as "juice brakes".

Ernie

trularin · #4 (**permalink**) 10-17-2003, 05:25 AM

ENTDOC, what stinks about the brakes?

Are they too hard to press? Not stopping fast enough? Too much eat?

What?

Good morning Ernie.

vettestr · #5 (**permalink**) 10-17-2003, 07:50 AM

Hello Ernie,
Have you played with the Juice brake set-ups and on what ? I am using the firewall mounted twin master cylinders still to look better and run slave cyl. After changing pedal length, folcrum points, piston diameters and adjustable bias controls I was out of ideas. The vette 4 piston calipers times 4 required more volume than I could supply no matter what I tried. So I tied the output of firewall MS into 1 line driving a slave that runs the input into the JUICE Brakes as you call them and then output back to stock metering block. First time or braking was way to sensetive. Changed piston diameter of slave cyl. and 2nd time was perfect. I have a cockpit mounted bias adjuster for fine tunning but am very happy. The engine bay looks right with twin firewall mounted MS and rest is hidden but doing its thing without a big vac booster in engine bay to be in the way. As designed by GM there is 5 or more brake applications in reserve accuater after a failure and warning light as a safety device so have to be aware its in system if stranger was to work on car with 2200 psi in holding tank. I did change from stock by moving things around and mounting to plate but was compact and easy to hide under car.

Ernie, I guess I just can not resist the wierd or road less traveled.

ENTDOC · #6 (**permalink**) 10-17-2003, 10:30 AM

Pedal pressure is fine, just no stopping power.I cannot lock up brakes at all. chuck

Bob Putnam · #7 (**permalink**) 10-17-2003, 11:19 AM

EntDoc,

I suspect that the vacuum "pressure" is running out of force to the master cylinder. Put a vacuum gage on the line to the booster. If your peak vacuum is under 22"hg, you might add a vacuum booster pump. Otherwise, try using a smaller diameter master cylinder. Your pedal travel will increase somewhat, but all life's a compromise...

Excaliber · #8 (**permalink**) 10-17-2003, 11:26 AM

I've only done routine maintainence of juice brakes so couldn't help you in that regard.

Jeff,,,,,,you sure you not from "down under"? ha ha

Ernie

dalola · #9 (**permalink**) 10-17-2003, 11:53 AM

If you have power steering, you may want to investigate one of the hydro-boost systems. Similar to the GN set up, but works through the P/S system.

A friend of mine just installed this system on his car. He did the big Baer brake swap, and just couldn't generate enough line pressure to work them effectively. Big cam, and low vacuum, so that was ineffective. The hydro-boost system is a very clean installation, and it flat out works!

If you don't already have P/S, you could add it just for the brakes, without actually plumbing in a rack.

I'm trying to think of the company that sells this system. They are in Michigan. I'll think of it eventually!

Anyway, something to think about.
~Dave