Hydroboost conversion?

Discussion in 'The whoa and the sway.' started by Bygblok, Jul 21, 2019.

  1. Darron72Skylark

    Darron72Skylark Well-Known Member

    I'm sure the CPP parts will work well, but the price tag, yikes!
    You can buy a new hydroboost from Summit Racing for $109. https://www.summitracing.com/parts/...MI1cqj07au5QIVIB6tBh1VwA80EAQYAyABEgKlKPD_BwE
    Still have to come up with mounting brackets and a master cylinder, but even so, you won't spend anywhere near $800.
     
  2. Dan Gerber

    Dan Gerber Founders Club Member

    True, especially if one uses their good master cylinder.

    Thanks for your response, BTW.


    Now for a slightly different point.....

    For those of you wavering back and forth between hydraulic and vacuum boosted brakes, CPP claims their system produces 1800 psi brake line pressure at the wheel cylinders. I'm guessing that this may be typical of OEM hydraulic boost systems?????

    Anyone know what our early 1970's OEM vacuum boosted power brake systems produce in the way of line pressure (assuming stock engine vacuum levels)?
     
  3. sailbrd

    sailbrd Well-Known Member

    All "Hydroboost" units are the same. The trick is to match up the other parts. The big trick is to make sure the brake rod is compatible. If I remember correctly the rod on the Astro Van is not quite compatible with the brake lever in our A bodies. Changing the brake rod is a bit of a production and I had Talon change that for me. Then you can add whatever master cylinder that will work. The final problem is getting the lines to work correctly with the power steering pump. I think GM had a pump with two return inlets to the PS pump. My system is a bit more complicated because I use a new style pump with a remote reservoir.

    So to answer Dan's question it is much easier to have someone put together a sorted out kit than to be junkyard dog and piece you own together. We are thinking of going hydroboost on our GN and will probably just go with Kirbans system.
     
  4. BillA

    BillA Well-Known Member

    I used the Astro Van booster purchased from Rock Auto. The rod that comes with the booster is not compatible. Instead of changing the rod I simply cut off the eye on the pedal end and cut threads with a 3/8-24 die. The rod is the perfect diameter and threads pretty easily with some cutting oil and a sharp die. The existing pedal rod is the same thread so I simply coupled them together, after cutting the factory rod to the proper length.
     
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  5. BillA

    BillA Well-Known Member

    You can purchase these brackets from Summit. Bolt them to the firewall and then bolt the booster to the brackets.
    https://www.summitracing.com/parts/tff-4650a/overview/
     
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  6. Darron72Skylark

    Darron72Skylark Well-Known Member

    This is probably the route I’ll go. Simple and inexpensive. The hoses become the most costly part.
     
  7. BillA

    BillA Well-Known Member

    I used braided PTFE hose with stainless steel AN fittings and adapters to convert from inverted flare to AN. The hose is about $5/ft and I used about 6 feet. The return to the pump is just compatible rubber hose with hose clamps. I probably spent $150 on the hose and fittings combined. You may be able to get the hoses made from a hydraulic shop for less, I don't know. I went with PTFE so I never even priced hoses from a local shop.
     
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