hydroboost installed

[brads70]

Hi Brad, Mine was a manual brake car also.This is the second system I peiced together. My unit is from a 95 Astro van with a $59 rebuild kit. I always run my unit direct from the pedal. You may have to modify the pedal rod . I use a large M/C bore  (1 1/8 )because the hydroboost unit has a short stroke and it pushes more fluid , the manual brake uses a smaller bore(like 7/8) and a longer stroke. One thing I must note. What ever M/C you use don't let the M/C bore bottom out when you fully depress the pedal. Most of the time I get Napa auto parts to make my lines bu,. on my pro touring car I am building I decided on some braided lines and fittings from Tallon Hydraulics.  http://www.cuda-challenger.com/cc/index.php?topic=75207.0

Thanks for the info! To prevent the M/C from bottoming out what do you suggest? An adjustable rod going to the pedal to limit the stroke? Have you driven this set up with 1 1/8" bore M/C yet? Cass at Dr Diff also recomends that size M/C too for a H/B set up!

[johns cuda shop]

The ajustment on the pedal rod is all you need. The stopping power is awesome ,you will never go back .

[brads70]

The ajustment on the pedal rod is all you need. The stopping power is awesome ,you will never go back .

Thanks! It's cold, damp, rainy,CRAPPY! day here now so maybe I'll head out to the garage and whittle out a bracket then.

What size is the pin/bolt on the pedal that the rod bolts to? 5/8'?

[73EStroker]

Brad - haven't deserted ya. Will get all the info and pictures together and post. Haven't been home since hunting trip. Like I have said - keep the pedal bellcrank setup that goes into the original brake booster. We just take a real short rod from the top of that straight into the MC bore. If you look closely if you go direct from the pedal the rod enters the MC bore at an angle and I beleive you are a good enough machinist to realise that uneven premature wear on the top of the MC bore will occur as brakes are used time and time again. The bellcrank also desensitises the pedal but believe me - like others said the braking power is really there. With the bell crank in place it makes for easy normal braking as it reduces the leverage on the plunger into the MC. 

[brads70]

Brad - haven't deserted ya. Will get all the info and pictures together and post. Haven't been home since hunting trip. Like I have said - keep the pedal bellcrank setup that goes into the original brake booster. We just take a real short rod from the top of that straight into the MC bore. If you look closely if you go direct from the pedal the rod enters the MC bore at an angle and I beleive you are a good enough machinist to realise that uneven premature wear on the top of the MC bore will occur as brakes are used time and time again. The bellcrank also desensitises the pedal but believe me - like others said the braking power is really there. With the bell crank in place it makes for easy normal braking as it reduces the leverage on the plunger into the MC.

Thanks Barry! My problem is I have manual brakes on now and don't have a bellcrank. I'll have to locate one....

[73EStroker]

OK Brad here goes.
Pictures HBEngine/HBEgine2 shows the Astro HB mounted on to the original PBooster studs. You only  have to hog out the holes a tiny bit. Also shows the lines I custom made and the 1" Alum spacer. The spacer is to step the booster away from the arms inside to enable the rod to be shorted enough and the HEIM and locknut to be installed. As you see the lines go out the other side from the one that Strawdog has installed. The booster can be rotated 180 degrees if you want. I wanted to keep the lines away up top away from the heat and engine. The schematic will follow on Monday evening to show the plumbing and what the catalog numbers are for all the Russel fittings to use plus there are some adapters from imperial to metric.

Pictures HBInside / HB Inside 2 show how I linked it up to the existing bellcrank that used to operate the power brakes. As you can deduce from these pictures one cannot take the Hydra boost rod direct from the booster to the brake pedal arm. It is too much of an angle and will place a large side load on the plunger into the HB unit giving premature wear or worse, brake failure. Also my friend has this setup on his 64 Corvette and it is too sensitive with the extra leverage placed on the rod. As you see the bellcrank will actually reduce the leverage but it is still a much better feel and the brakes are like Porsche brakes now with this setup. Not going to get into physics here but I have driven both setups. This is easier to drive with if you have a heavy brake foot.
To get the rod out of the Astro booster simply place in a vise with soft jaws, put vise grips on the rod and tap with a hammer and it will come out. There are little indents in the HB plunger that hold it in. Simply tap it back when you are done. I cut mine down with the minimum left that would allow thread length for the HEI and the locknut. Thread is 3/8 NF. HEI is 3/8 hole for the mopar bolt on the bellcrank.
I made a small button to sit between the booster unit and the master cylinder. 76 Cordoba master cylinder single reservoir. This takes up what would be pedal freeplay if you do not install one. I have brakes that operate right at the top of the pedal range and the feel is very similar to what Diesel pickups are.
Plumbing is simple - PS pump to booster to steering box. Return drain is simply parallel between the steering and booster back to the pump.

So when you get the scanned schematic hopefully everything will fall into place.

With this setup I spent a total of about $130 for everything and have extreme stopping power.

Barry

[brads70]

  sweet!  Looks like I'm going to have to hunt up the bellcrank assembly as mine doesn't have one. I wonder if the actual pedal arm is different from what I have too?
I made a small button to sit between the booster unit and the master cylinder. 76 Cordoba master cylinder single reservoir.
Can you explain this button a little? I don't quite follow ya? So the master your using is a 76 Doba? The one in the picture looks like a dual reservoir?
Thanks Brad

[73EStroker]

When you have the master cylinder and the HB unit in your hand you will see what I mean. If you joined them together as is then the gap would exist. The MC that I have chosen had a deeper plunger than the Astro Van unit did

[brads70]

Here is a drawing Barry (73EStroker) sent me and asked me to put it up here for future reference!
Lots of good info! Thanks Barry! 

[73EStroker]

Brad - that dual reservoir is the original Astro Van part. Since then I have installed the Cordoba reservoir. Did you figure out the small button yet? If you bolt the reservoir and the booster together you will see what I am talking about.
just got back from Guelph yesterday.

[brads70]

Brad - that dual reservoir is the original Astro Van part. Since then I have installed the Cordoba reservoir. Did you figure out the small button yet? If you bolt the reservoir and the booster together you will see what I am talking about.
just got back from Guelph yesterday.

No haven't had time to mess with it yet, snow is finally here and it's money making time for me.( I repair snowblowers)

[Gumby]

Great info here! Does anybody use a small cooler in their return line? I would think that would extend the life of the pump a lot, since it is now doing double duty. Would one be needed? Looks like the "kit" I bought off ebay years ago has everything I need, including an adjustable rod. Don't know if I need to make a small space for room yet, but I'm thinking not.

[brads70]

Great info here! Does anybody use a small cooler in their return line? I would think that would extend the life of the pump a lot, since it is now doing double duty. Would one be needed? Looks like the "kit" I bought off ebay years ago has everything I need, including an adjustable rod. Don't know if I need to make a small space for room yet, but I'm thinking not.

Yep mine has a small cooler in it now. As the headers ( 440)are so darn close to the steering box it was really getting hot. This little cooler did the trick!