Hydroboost Braking - Details of installation

Discussion in 'Suspension, Steering, Brake & Wheel Topics' started by mrvedit, Feb 27, 2010.

  1. mrvedit

    mrvedit Veteran Member

    Jun 12, 2009
    Ann Arbor, MI
    What is Hydroboost Braking?

    The vast majority of power braking systems use engine vacuum and a large diaphragm within the brake booster to multiply the driver's brake pedal pressure. In contrast, Hydroboost braking uses the hydraulic pressure from the power steering pump to provide power braking.

    The Hydroboost unit is made by Bendix and is mostly used by GM and Ford for their diesel pickup trucks (e.g. F350) because diesels produce no vacuum. They are also used in the Mustang GT and a few other performance cars. In brief, Bendix makes one core for Ford and a different one for GM. I learned the hard way that a Ford unit will not fit a Camaro.

    It appears that all the aftermarket Hydroboost units are built by Hydratech Braking Systems http://www.hydratechbraking.com/ which only sells through its dealers, including Classic Performance Products (CPP). Hydratech buys new Bendix units, adds a custom mounting plate for each type of car, and a top-of-the-line braided hose kit and adapters for the type of car.


    A Hydroboost system provides superb power braking even in cars with high performance engines that produce very little vacuum. It makes your hot rod much SAFER!

    Significantly, the unit is also much smaller than any vacuum power booster, making it easier to install a Big Block, large valve covers or other items. As you can see in my pictures, it is much easier to work in that area of the engine compartment.

    Installing on my '81 Z28

    The first picture shows the factory vacuum power booster. Notice that a vacuum canister was added to improve the braking. Not in the picture, I had also added a small electric vacuum pump to improve the braking. Even with the add-ons, I could NOT lock the brakes even with 200+ lbs of pedal force. Particularly challenging was stop and go city driving where the engine was rarely above idle.


    (BEFORE - Factory power brakes augmented with Vacuum Canister - very marginal brakes)

    After some experimentation, I finally purchased and installed the Hydroboost package from CPP with chrome master cylinder and complete hose package. The fully installed system is pictured below:





    (AFTER - Hydroboost fully installed.)

    Fantastic Braking!

    The end result is nothing short of a phenomenal improvement. The brake pedal feel is excellent and I can easily lock the wheels. It is not overly sensitive, more like a BMW than the too-sensitive Pontiac G6 I recently rented. I highly recommend it.


    While I estimate a typical installation would take 5 - 6 hours, it took me much longer because I also replaced the master cylinder and front brakes lines (with a good kit from NPD) and had to significantly re-bend the spiral ends to fit the final non-stock position of the proportioning valve. I also had to make a new partial rear line and deal with some problems described below.


    (Picture of the basic Hydroboost unit with mounting plate specifically for Camaro.)

    My '81 has metric "O-ring" power steering parts (actually '86 IROC parts). This was no problem because the Hydratech supplied parts included custom brass O-ring inserts. However, since I had already purchased Aeroquip O-ring adapters, I used those instead:


    (On the left are the supplied parts, on the right what I used.)

    I want to emphasize that there were absolutely NO problems with the parts supplied by Hydratech. Since I had "experimented" with Hydroboost before purchasing the CPP product, I had been in touch with owner Paul Clark and can vouch that he gives good advice and good service. The Hydratech supplied Hydroboost unit, Aeroquip Teflon braided hoses, connectors, adapters and other parts are absolutely top quality. Even the supplied bolts are premium chromed.

    The problems were all due to the master cylinder and proportioning valve added by CPP in their "package":


    First, the proportioning valve was attached to the side and below the master cylinder with a heavy bracket. Even though this was labeled a "70-79 Camaro" part, there is no way it will fit a 2nd gen, as it overlaps the fender by about 2 inches. Therefore I ended up mounting the proportioning valve underneath the master cylinder, which required making short custom brake lines. (It took several tries before the flair ends didn't leak.) Next, the master cylinder had a massive leak which took an hour to correct.

    Buying it

    As I mentioned, the Hydratech kit is absolutely top quality. They sell only through dealers and dealers are listed on their website. I bought the CPP "complete" chrome kit through Summit Racing, but you may want to just buy just a basic kit (with hoses!) and an alternate master cylinder. (The stock 1.25" bore master cylinder has too big a bore to fit the Hydroboost unit.) A basic kit with hoses and the necessary adapters is $695 (list price). While Hydratech doesn't sell the Hydroboost units retail, they do sell accessories, hoses and master cylinders:


    Don't buy the "Universal kit"; I bought it too and returned it; it will not fit without major mods. Don't buy any used Ford GT units on Ebay; I tried that too and they don't fit.


    IMHO, it seems crazy to spend many thousands of dollars on your hot rod and hundreds or thousands of hours of your time, and then risk it all and your life with brakes that barely work. For the price of a new carb, you can have the best brakes on the road and enjoy your car more.
  2. Brown`77Z28

    Brown`77Z28 Veteran Member Lifetime Gold Member

    Dec 11, 2005
    The Netherlands
    That looks really awesome, however I`ve always wondered if your steering pump can keep up with things when you are on a autocross track with a lot of quick turns and fast braking????
    Any experience?????
  3. earlysecond

    earlysecond Veteran Member

    Aug 9, 2002
    Altoona, PA
    Well written and well played!

    If I could do all of this with stock components for half or less of the kit price I would consider it. I have vacuum out the azz but I like the feel of the hydro systems on my later Chevy trucks.

    You did a nice job, kudos to you and thanks for sharing.

  4. mrvedit

    mrvedit Veteran Member

    Jun 12, 2009
    Ann Arbor, MI
    Sorry I do not have any experience with this in my Camaro, but I suspect that the steering uses much greater volume of hydraulic fluid than the braking. You could ask Hydratech (Paul Clark) for a reference.

    However, I used to race BMWs and many BMWs use a similar braking system; don't think they had a particularly large power steering/braking pump.
  5. 79camaro2001

    79camaro2001 Veteran Member Lifetime Gold Member

    May 4, 2003
    Monroeville, PA

    Stock pumps I would say have trouble, but most people modify their pumps for higher pressure or volume I can't recall right now.
  6. mrvedit

    mrvedit Veteran Member

    Jun 12, 2009
    Ann Arbor, MI
    You are right the hydroboost system do have a fast response and good feel.

    You might be able to find a complete GM hydroboost system at the junkyard. Since the GM truck lines would be much too long for your car, you would need to deal with that. Perhaps someone can shorten them; or it costs about $150 for the Aeroquip Teflon hoses (needed for the 1500psi pressure) and fittings. You would also need to deal with the firewall mounting; the truck mounting plate would probably not fit your Camaro. You can buy Hydroboost units from your auto parts store for about $150, but I don't which model best fits a Camaro and you would still have the mounting plate issue. (It is also important to get the right model with the correct brake pedal rod.)

    I had originally hoped to provide a parts list for a cheaper get-it-yourself kit, but gave up. When you add everything up, Hydratech is basically charging you $100 for a billet mounting plate and that is all the profit they are making.

    Look for sales - CPP sometimes runs sales and I was lucky to use a 10% discount coupon with Summit. Call the other (smaller, more personal) Hydratech dealers. They are great systems, but not trivially cheap.
  7. PetieG383

    PetieG383 Veteran Member Lifetime Gold Member

    Oct 28, 1999
    Wynnewood, Pa USA
    Can someone make this a sticky?

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