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My installation of hydroboost and hydraulic clutch

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by Yukon Jack, Feb 6, 2007.

  1. Yukon Jack

    Yukon Jack 1/2 ton status

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    Thought I would do a detailed post about the install of a hydroboost system and hydraulic clutch from a donor 1989 Chevy 1 ton (old body style) on to my 1969 Chevy K20. I installed these two items as I was swapping in the 89's 454 into my 69 K20.

    I really like the hydroboost brake system but, of course, I was used to manual brakes so any assist was welcome.

    The hydraulic clutch is also nice. I would have had a major problem using the stock z-bar setup with the headers and the swapped in bbc.

    When I started contemplating this project, it was mentioned that it might be wise to reinforce the firewall due to the weight of the hydroboost and fact that I was adding the hydraulic clutch. I had a buddy cut me this reinforcement for my firewall with his plasma cutter.

    [​IMG]

    Another buddy made me the metal shim you see that positions the hydraulic cylinder correctly so the push rod will attach to the clutch pedal.

    [​IMG]

    The 1989 old body style 1 ton hydraulic clutch master is angled requiring the shim. I later found out that the new body style hydraulic clutch master would not have required that shim. Regarding the shim for the hydraulic clutch cylinder, the way I have it made, it attaches right next to the hydroboost bracket. The template is angled so the bottom is 5/8" thick and the top of the shim angles down to 1/16" thick. The shim is 2 5/8" wide x 2 5/8" tall.

    I got the cylinder mounted on the firewall, threaded the push rod and am using a 5/16" threaded clevis rod end to attach the rod to the clutch pedal. Cycles freely and the rod will push in as far as needed. Might have to make a
    stop to limit the clutch pedal.

    [​IMG]

    I am using the 1989's engine and bellhousing so the slave cylinder was already attached to the bellhousing.

    Next I got the hydroboost brake cylinder hung on the firewall. I had to knock the two lower stud bolts off the pedal assembly and drill a couple holes but no biggie. Because of how this is mounted, I have to modify how the steering column attaches to the firewall as the brake booster bracket covers one of the attachment holes.

    [​IMG]

    Mounted the rod to the brake pedal same as with the clutch. The brake booster rod is 3/8" while the hydraulic clutch rod is 5/16". I cut off the end of the brake booster push rod, threaded it and got it connected to the brake pedal using another clevis rod end.

    [​IMG]

    [​IMG]

    I did have to have the high pressure line modified. I took the 1989 1 ton's high pressure line along with the stock high pressure line and had them combined - this allowed the metric end to be at the hydroboost master cylinder and the flare end to fit the stock steering box.

    Here are some finished pics.

    [​IMG]

    [​IMG]
     
    Last edited: Apr 25, 2009
  2. CDA 455

    CDA 455 3/4 ton status

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    Nice, nice, nice :bow: :bow: !!

    I read on another thread that I have to change my brake pedal because my pedal is different than a hydroboost brake pedal. Is this true or what :dunno: ?
     
  3. Yukon Jack

    Yukon Jack 1/2 ton status

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    I used my stock pedal assembly - just had to figure out the proper location to attach the brake rod to the pedal.
     
  4. CDA 455

    CDA 455 3/4 ton status

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    Am I on drugs or did you post this thread twice :eek1: :D :haha:?



    In regards to the pedal: Like you showed in the pics?
     
  5. makovai

    makovai 1/2 ton status

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    VERY VERY NICE. I wish had the guts to do that. I already have all the parts i just cant convince myself to do it.

    Nice work though
     
  6. Yukon Jack

    Yukon Jack 1/2 ton status

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    Got it posted here and over in the garage. Initially posted here but figured alot of people don't go to this section and would miss it if not posted in the garage.

    You lost me on the second part of the quote above - course it's late in the work day so my mind is a bit mushy at this point. :doah:
     
  7. vtblazer

    vtblazer 1/2 ton status GMOTM Winner

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    How about the pump?

    Was it and easy addition? Did you keep the serp belt set up?

    Any pics of it?

    Nice job. :bow:
     
  8. Yukon Jack

    Yukon Jack 1/2 ton status

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    Everything except for the power steering gear box was from the donor vehicle (engine, bellhousing, power steering pump, pulley's) so I didn't have to worry about anything except for adapting the high pressure metric line to the stock flare type power steering box.

    It was funny cause when I first got the donor truck and posted pics of it here - people were asking me if I was using the hydroboost and if I would sell it or the hydraulic clutch. I literally had to reseach to figure out what the hydroboost was. Didn't take me long to decide to use it all on the 69. Having a complete donor vehicle sure made it easy.

    This year truck doesn't use a true serpentine belt system. I'll dig around and see if I have a pic of the belt system. I got rid of the a/c and smog pump so I had to find some shorter belts.
     
  9. OLD DAWG

    OLD DAWG 1/2 ton status

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    Some of us had to give up on a manual swap. I'm going with a TH 400 and doubler setup due to nerve problems in my left leg. Nothing like getting a garage full of parts including a 465/203 setup for it and not using it. Oh well. Nice clean work Y.J.
     
  10. bp71k5

    bp71k5 3/4 ton status Premium Member

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    Yukon Jack, when you say the later version clutch master cylinder would not require the angled shim, how much later? I'm loooking at a '95 master and slave combo kit with hoses included.
     
  11. Yukon Jack

    Yukon Jack 1/2 ton status

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    The year 1989 had a new body style and old body style truck available. The new body style had the master that would not have required the shim. So to be safe I think anything 1990 and after wouldn't need it. When you go to the parts store and look at one you will be able to visibly see if one will be needed. The mounting surface for the one for the old body style was visibly angled.
     

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