Disc vs. Drum Master Cylinder Bore Size?

Discussion in 'General Maverick/Comet' started by silver70, Jan 27, 2020.

  1. mojo

    mojo "Everett"- Senior Citizen Supporting Member

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    This is what experts from "Master Power Brakes" say about cylinder bore size! What bore size do you need for manual brakes? I would be inclined to take their statement as fact!

    Usually a bore size of 1" or smaller is recommended. This is due to the the fact that a smaller bore master cylinder will provide more travel in the pedal than a larger bore master cylinder. Therefore, more effort will be required if too large a bore master cylinder is used. The smaller bore master cylinder will provide the same line pressure at a lower pedal effort.
     
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  2. silver70

    silver70 Eric

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    I think the effort required is high by comparison to power brakes, yes. That's obvious; otherwise brake boosters would not exist. However, I want it to be as reduced as possible given the fact that I have chosen to run manual discs. Basically, I want my elected scenario to be as good as it can be given the constraints of the factory parts that Ford opted to utilize. I'm not expecting a miracle; only better performance. I have become very reasonable in the 12 years I have not been able to drive my Maverick. LOL!
     
  3. TeeEl

    TeeEl Member

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    It's still gonna be high effort either way without power assist.
    Use the master cylinder that is designed for your application...
     
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  4. Maverocket

    Maverocket Bob Williams

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    I have discs from a 75 Mav on my 71 with a 74 manual disc brake master. The pedal feel is very close to the stock drum setup but it stops waaay better.
     
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  5. bmcdaniel

    bmcdaniel Senile Member

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    Last edited: Feb 2, 2020
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  6. m in sc

    m in sc Member

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    yeah, my maverick is a stock disc brake car, no power, but has very good pedal feel, not hard to stop at all. But my galaxie is a factory power drum brake car, and im pretty sure leeds had the pedal ratio wrong for the 66 since the new 4 pot calipers on that kit have a harder pedal feel than the stock drum setup, which initially makes no sense. its different earlier than that witht he pedal ratios on the galaxies, i think. even THEY said to try it and report back.

    On the military vehicles we were building, we had requirements to have 'x' amount of pedal force to stop a vehicle with NO power assist on a 30 degree incline. this was a 6000 lb vehicle built from scratch. It was all doen with pedal ratio and MC sizing. Point being, you can get good pedal feel w/out power brakes, it just depends on the pedal ratio and hydraulic ratio, basic physics really.
     
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  7. silver70

    silver70 Eric

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    I poked around on my parts shelves and found a 15/16" bore MC. Took it apart and found a gelatin-like, somewhat gritty, residue on the seals. Kind of like Vaseline with little particulates of gravel. The seals appear to be in good shape though and there's no scoring on the bore or piston. I'm going to go through it really well, clean it up, paint it, and try it. I believe I may have picked this up at a salvage yard, years ago, with the intention of swapping it in, but never got around to it. Still gotta track down an auto pedal pivot bracket though...
     
  8. 71gold

    71gold Frank Cooper Supporting Member

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    most of the time the pic is just pic, not representing the part at all.
     
  9. Krazy Comet

    Krazy Comet Tom

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  10. m in sc

    m in sc Member

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    the pic is accurate. I linked a different one with ports on the correct side.
     

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