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  • Brakes: Advice needed on Hydrovac system for Steering and Brakes

    HI,
    I have a 59 lark 2dr hardtop, and it has the original drum brakes, with the single master cylinder. Im about to have them upgrade to the Turner brake system, with a dual master cylinder. I also have a GM rear end in it, also with drums. I have a Chevy 350 in it, so its fast and a bit heavy. Besides having an unsafe single master cylinder, discs on all 4 just seem like a good idea. As you are aware, the 59 Lark is an under-floor master cylinder, so its not really possible to put a brake booster under there.

    My mechanic is recommending the following:

    - Discs all the way around
    - Upgrade to power steering (which is something I wanted to do anyways)
    - Get a hydrovac system, which allows the brakes to use the power steering pump to also power the brakes- thus eliminating the need for a separate booster for the brakes (that brake booster wouldnt fit under the car anyways).

    Good idea? Bad idea? Alternatives?

    Let me know your thoughts, and thanks in advance.

    Craig

  • #2
    With the correct master cylinder piston diameter, you do not "need" a power booster. I have two 54 Studes with 4 wheel disc brakes that will prove that. One has Wilwood Dynalite calipers all the way around, the other has Wilwood, GM copy in the front and Ford calipers in the back.
    Neither have nor need power boosters..! A two toe push is all that's required.
    A little homework on caliper piston size vs. master cylinder size by you and or your mechanic will save you time and money and him a little time.

    With a small Chevy in the front of a 59 Lark, power steering also seems over kill. I recently sold my 59 Lark wagon with a 259 and a heavy ol iron transmission in it. No power steering, and a heavier engine than the Chevy to boot. Add in my smaller than stock steering wheel...
    Check out Hankook, Optima tires. Believe it or not, these tires will go a LONG way in lightening the perceived feel of heavy steering. A second thing, if the front suspension is in good condition and properly lubed, this also goes a long way in light steering feel.

    Mike

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    • #3
      That's called "Hydraboost" not "hydrovac". And, yes it is a good idea. Several of my GM Suburbans run hydraboost, and it is pretty trouble-free.
      Gord Richmond, within Weasel range of the Alberta Badlands

      Comment


      • #4
        discs on all 4 just seem like a good idea
        Your car, your build, your money. Just some thoughts. Have you weighed the car front and rear? On hard stops with weight transfer, your front brakes do about 75% of the work. Unless one is road course racing, it's unlikely one would overtax those GM rear drums. JMHO, but leave the rear drum brakes and that will retain the original parking brake. Rear discs are overkill on a street driven Lark. No way to guess what your mechanic is charging for rear disc brakes, but get that cost broken out separately. A local guy just spent more than $1,000 for rear discs from which he might not derive any benefit.

        As you are aware, the 59 Lark is an under-floor master cylinder, so its not really possible to put a brake booster under there.
        As is seems you are not aware, for more than seventy years, there has existed a free standing Hydrovac used by most OEMs back in the day. Studes with frame mounted master cylinders had a separate Hydrovac mounted on the fenderwell beside the engine. Some here have had difficulties with these, but millions of them worked well all these years.

        jack vines
        Last edited by PackardV8; 05-03-2019, 11:02 AM.
        PackardV8

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        • #5
          Well, lots of opinions- thanks for the options! Although it would be better if there was one single consensus on what is best, I like options too. :-)

          So far Im hearing:

          1) Since its just a street car, no need for rear discs (I dont plan on driving like a crazy person, so drums in back sounds better and will keep my cost down)
          2) There already exists a hyrdovac or hydroboost system for Studes- would like more info on this if possible please
          3) If I get the right pistons and calipers, I may not need power added to the brakes- that also sounds like a great plan, and will save on cost
          4) Regarding power steering: not really needed if I get the right tires. However, Id like my wife to be able to drive the car sometimes, so power steering would be mostly for her benefit. Im 6'2", 200 lbs so I can muscle the wheel around. I had the entire suspension bushings for the front and rear completely redone about 3 years ago, so all that is in good condition. If its easy to add power steering, that may be something I add anyways.

          Thanks for the advice, keep it coming!

          I also will be at La Palma end of May, so I may arrange to get parts at that time depending on which direction this goes....

          Comment


          • #6
            Update from my mechanic:

            - He has not been able to find a hydrovac or hydroboost system that will work, everyone here has been advising against that anyways, so thats fine.
            - He has found parts from a company in Florida (didnt tell me the name) that will provide a new front SPINDLE and new front discs, calipers, bearings, etc, along with a dual master cylinder and proportioning valve and new lines. I would keep the rear brakes as drums, no need to upgrade to discs back there.

            Total for parts and labor would be $3155

            I dont see the need for new spindles. That seems like overkill.

            The Turner system is about $1000 in parts, between the deluxe front brakes system, dual M/C and M/C bracket, and allowing for some extra cost for shipping, new lines and other odds and ends.

            I live in Los Angeles; most things are pretty expensive here- but I dont know that these new brakes are $2100-in-labor expensive. Considering that is more than the purchase price of the car when I bought it, I think Im going to have to see if I can find another shop. But rest assured Im upgrading as the single master cylinder is on my mind every time I drive it.

            Im sure I could do 90% of the work myself: its that last 10% and more important: the TIME to do this myself, that give me pause.

            Comments and recommendations are welcomed.

            Comment


            • #7
              Originally posted by creegster View Post
              Update from my mechanic:

              - He has not been able to find a hydrovac or hydroboost system that will work, everyone here has been advising against that anyways, so thats fine.
              - He has found parts from a company in Florida (didnt tell me the name) that will provide a new front SPINDLE and new front discs, calipers, bearings, etc, along with a dual master cylinder and proportioning valve and new lines. I would keep the rear brakes as drums, no need to upgrade to discs back there.

              Total for parts and labor would be $3155

              I dont see the need for new spindles. That seems like overkill.

              The Turner system is about $1000 in parts, between the deluxe front brakes system, dual M/C and M/C bracket, and allowing for some extra cost for shipping, new lines and other odds and ends.

              I live in Los Angeles; most things are pretty expensive here- but I dont know that these new brakes are $2100-in-labor expensive. Considering that is more than the purchase price of the car when I bought it, I think Im going to have to see if I can find another shop. But rest assured Im upgrading as the single master cylinder is on my mind every time I drive it.

              Im sure I could do 90% of the work myself: its that last 10% and more important: the TIME to do this myself, that give me pause.

              Comments and recommendations are welcomed.
              I just put the Turner front disc brakes set up on my 60 Lark wagon. You can do it. Good instructions and Jim will help via phone calls. Will start on the dual master next.
              I also have a large area to work on the car so I could tear off the old stuff and spread out the new to figure it all out. This kept my frustration level low.
              John

              Comment


              • #8
                Originally posted by creegster View Post
                Well, lots of opinions- thanks for the options! Although it would be better if there was one single consensus on what is best, I like options too. :-)

                So far Im hearing:

                1) Since its just a street car, no need for rear discs (I dont plan on driving like a crazy person, so drums in back sounds better and will keep my cost down)
                2) There already exists a hyrdovac or hydroboost system for Studes- would like more info on this if possible please
                3) If I get the right pistons and calipers, I may not need power added to the brakes- that also sounds like a great plan, and will save on cost
                4) Regarding power steering: not really needed if I get the right tires. However, Id like my wife to be able to drive the car sometimes, so power steering would be mostly for her benefit. Im 6'2", 200 lbs so I can muscle the wheel around. I had the entire suspension bushings for the front and rear completely redone about 3 years ago, so all that is in good condition. If its easy to add power steering, that may be something I add anyways.

                Thanks for the advice, keep it coming!

                I also will be at La Palma end of May, so I may arrange to get parts at that time depending on which direction this goes....
                My neighbor has a 350 SBC powered 60 Lark 2 dr. We put Turner front discs on it with EBC Greenstuff pads. It has a turner dual master kit on it with a 1" bore dual master. It too has a Chevy 10 bolt rear end with drums. It stops fine. No power steering with 70 series radial tires. It drives ans steers fine. The key to good steering was using a 63 style Saginaw steering box and having well lubed functional king pin thrust bearings. Sizing the master is important. For street driving rear discs are expensive overkill that do nothing but spend money.
                james r pepper

                Comment


                • #9
                  Thanks everyone-

                  It looks like my mechanic is overthinking this, and heck- I can do the job. The only thing I am hesitant about is heating and properly seating the bearing spacers. But Im sure I can figure that out as well.

                  Thanks everyone for all the advice, Ill let you all know how it goes. I dont think Ill have this setup for La Palma, but we'll see.

                  Craig

                  Comment


                  • #10
                    Here is another question for everybody. I have the front Turner system/stock rear drums/adjustable
                    proportioning vavle/stock hydrovac power brakes on my 62GT. System has worked great for ten+ years. I want to add a dual master cylinder for safety. Some have suggested to plumb the front discs through the stock hydrovac and the rears with no power assist [then I can use my existing power brake pedal]. Is this acceptable? Or should I search out a manual brake pedal for a C/K and go with the 1 inch bore MC [mentioned earlier] and remove the hydrovac unit? Getting older and seem to care about safety more and more...

                    Comment


                    • #11
                      I would throw that stock power brake pedal as far away from the car as possible. They have NO mechanical advantage when there's a loss of assist from the booster.
                      64 GT Hawk (K7)
                      1970 Avanti (R3)

                      Comment


                      • #12
                        Originally posted by calntvs View Post
                        Here is another question for everybody. I have the front Turner system/stock rear drums/adjustable
                        proportioning vavle/stock hydrovac power brakes on my 62GT. System has worked great for ten+ years. I want to add a dual master cylinder for safety. Some have suggested to plumb the front discs through the stock hydrovac and the rears with no power assist [then I can use my existing power brake pedal]. Is this acceptable? Or should I search out a manual brake pedal for a C/K and go with the 1 inch bore MC [mentioned earlier] and remove the hydrovac unit? Getting older and seem to care about safety more and more...
                        I would suggest that you start your own thread about your specific brake system so as to not cause confusion.

                        Comment


                        • #13
                          A hydroboost system would be very expensive to retrofit to your car. I am not even sure how you would do it on a frame mounted MC. I am sure it has been done, but at what cost?
                          The hydrovac would probably not be practical, as the ones I have seen are just one brake line in one brake line out with one vac hose. Even the one I took off of a 1972 Chevy grain truck had a single circuit MC.
                          That means it would not work with a dual chamber master cylinder. The advanage to the old hydrovac set up was that the unit could be mounted remote from the MC, as Jack pointed out. Guessing you would need two remote mounted hydrovacs to make it work on a split system. I think I would just try and get the MC sized properly to work without boost.

                          Jack gave you some outstanding advice regarding disc drum set up. Four wheel disc brakes are not needed on a street car. I modified a 68 El Camino to enable it to competently pull a 9000 pound load. I opted for 12 inch Corvette rotors in front with truck calipers and brake pads, but used 11 inch drums in the rear. I have had no issues stopping that car, even when my trailer brakes malfuncitioned on one trip. Once the brakes are good enough to lock up, you can't get any better for the one time panic stop. Yes, I realize the four wheel brakes will not fade as badly during repeated high speed stops. How often are you going to be doing that? You can use an adjustable proportioning valve to dial in the balance front to rear.

                          Comment


                          • #14
                            Originally posted by Lynn View Post
                            A hydroboost system would be very expensive to retrofit to your car. I am not even sure how you would do it on a frame mounted MC. I am sure it has been done, but at what cost?
                            The hydrovac would probably not be practical, as the ones I have seen are just one brake line in one brake line out with one vac hose. Even the one I took off of a 1972 Chevy grain truck had a single circuit MC.
                            That means it would not work with a dual chamber master cylinder. The advanage to the old hydrovac set up was that the unit could be mounted remote from the MC, as Jack pointed out. Guessing you would need two remote mounted hydrovacs to make it work on a split system. I think I would just try and get the MC sized properly to work without boost.

                            Jack gave you some outstanding advice regarding disc drum set up. Four wheel disc brakes are not needed on a street car. I modified a 68 El Camino to enable it to competently pull a 9000 pound load. I opted for 12 inch Corvette rotors in front with truck calipers and brake pads, but used 11 inch drums in the rear. I have had no issues stopping that car, even when my trailer brakes malfuncitioned on one trip. Once the brakes are good enough to lock up, you can't get any better for the one time panic stop. Yes, I realize the four wheel brakes will not fade as badly during repeated high speed stops. How often are you going to be doing that? You can use an adjustable proportioning valve to dial in the balance front to rear.
                            Thanks Lynn

                            That all aligns with the direction Im heading:

                            - No Hydroboost
                            - No power brakes
                            - Discs in front only
                            - The Master Cylinder Im looking at is a dual with a 1" bore, so it should be plenty strong enough
                            - Ive talked on the phone with Mike Van Veghten, who has give me some GREAT advice, and also confirmed that I can do the upgrade myself, no need to pay over $2K to my mechanic to do this.

                            Comment


                            • #15
                              I think you are on teh right track now (I just saw this post) The only thing I would caution is heating of the bearing spacers. TI thought I could get it hot enough with two propane torches and ended up with them seizing about 1/8" away from being fully seated. And it was no joy trying to cut and break them loose to install new ones. I ended up buying one of those small Oxy/ acetiline torches for about $50, and it did the trick. Point is, don't try it without enough heat.
                              Ron Dame
                              '63 Champ

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