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K5 Diesel to Vac booster pedal spring?

Discussion in 'Suspension, Steering & Brakes' started by Tja1161, Oct 17, 2020 at 1:58 AM.

  1. Tja1161

    Tja1161 Junior Member

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    Tom
    Truck Year:
    1983
    Truck Model:
    GMC JIMMY K5
    Engine Size:
    350
    I converted my K5 6.2 to a gas engine and swap in a power booster set up. I had to buy a diesel pedal and assumed the spring originally had to go on the power brake pedal. I have a lot of travel with spring on and am wondering if I need the spring? Thanks in advance for the help
     
  2. RoryH19

    RoryH19 Full Access Member

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    350 TBI
    If I recall, diesels come with hydroboost not vacuum assist. Did you convert the hydroboost when you swapped the engine? Brake pedal setup will be different between gas and diesel too. I have a gas powered k5 if you need a pic.
     
  3. Craig 85

    Craig 85 Full Access Member

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    To add to RoryH19's comment, I believe the hole for the push rod on the brake pedal shaft is in a different location than the hydro-boost. I recall seeing a thread on here a while back when someone converted from vacuum to hydro.
     
  4. Tja1161

    Tja1161 Junior Member

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    Truck Model:
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    350
    Sorry if my post was confusing. Yes, the pedals are different. My K5 was originally a diesel with hydro-boost. I bought a gas brake pedal from a member here when I converted to vac assist.
    My question is do the gas trucks have a brake pedal spring like the diesel? I only see a spring in the manual for JB8 diesel brakes. I put the spring on but I am wondering if I needed it as the brake pedal travel is huge before the brakes engage.

    Thanks
     
  5. bucket

    bucket Super Moderator Staff Member

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    I believe the spring is only for the hydroboost pedal. I don't recall a spring on any of my vacuum brake pedals.
     
  6. Tja1161

    Tja1161 Junior Member

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    Engine Size:
    350
    Thanks. Maybe i will take it off and see what it does. However, I seem to recall it was pain to install. Thanks
     

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