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Technical Model A hydraulic brake conversion

Discussion in 'Traditional Hot Rods' started by Matthew Davis, Feb 19, 2023.

  1. Matthew Davis
    Joined: Nov 9, 2022
    Posts: 25

    Matthew Davis

    I have torn down and cleaned everything. The intention is to rebuild the mechanical brakes and run them with a mild banger for now. Almost everything has wear and needs to be replaced from the rods to the linings. I think I can just get the drums turned as they look pretty good and Ok by measurement. The parts list got fairly expensive and it got me thinking about the cost of a hydraulic conversion. I've seen the boling broskits for about $3500 and all new and clean parts sounds like fun but is out of range. Can anyone give me a realistic cost estimate for a hydraulic set up or am I for sure in that $3000 range? Also the rear drums had a little oil in them, from what I've found online it should just be a result of over filling the rear end. I read on the ford barn that the rear end seals are to keep grease out not to keep oil in. I would love to not tear down the rear end at the moment but definitely don't want any oil getting in to freshly rebuilt brakes, if anyone has any thoughts on this as well I'd love to hear them. Thanks
  2. panhead_pete
    Joined: Feb 22, 2006
    Posts: 3,487


    Reach out to @RICH B he sells complete sets of loaded Bendix brakes and you will be able to peice together the rest much cheaper than the ones you mentioned.

    @IronTrap Garage on Youtube plus many others go through fitting these and the mastercylinder etc.

    Old Yankee sell brackets etc if you need them.
  3. If you can find good used drums, you're miles ahead...."if" is the big thing. I can generally get brakes on a car in the 1000-1500 range depending on what master cylinder kit is used and drum condition.
    sko_ford and gimpyshotrods like this.
  4. AccurateMike
    Joined: Sep 14, 2020
    Posts: 641


    I saw this on FB Flathead Era Engines & Parts
    "1939-948 Ford Hydraulic brakes backing plates and drums. If you need one backing plate, a pair, or complete set with everything on then- I have what you need. Call 303-293-3673 or email [email protected]"

    I don't know if this helps. Sure looks like it.

  5. If you intend to run wire wheels; you are pretty much limited to early Ford Lockheed or repop Lincoln brakes. Unless you like thick spacers and odd looks.

    While there is more work and expense involved it would be a good move to go with later model spindles at this time.
  6. 1946caddy
    Joined: Dec 18, 2013
    Posts: 2,078

    from washington

    I'm doing about the same thing as you in putting hydraulic brakes on a stock Model A.
    A neighbor gave me a 40 Ford rear end with the brakes on it and I bought a 46-48 front end for $100.00 off of craigslist. Using the squareback spindles and brakes up front and 40 brakes off the rear end. Also using Posie reversed springs in the front and back along with an Okie Joe 4" dropped axle.The easiest for the brake pedal is to buy the Boling Bros. battery box which bolts in and comes with a master cylinder and uses the stock brake pedal.
    550x16 & 700x16 Firestones on 16" wires.
    Going to look like a hotrod and sound like a lawn mower with the stock engine.
  7. Hey lawn mower is way meaner than my banger
    Texas Webb and winduptoy like this.
  8. 1946caddy
    Joined: Dec 18, 2013
    Posts: 2,078

    from washington

    Hitchhiker likes this.
  9. el Scotto
    Joined: Mar 3, 2004
    Posts: 4,699

    el Scotto
    from Tracy, CA

    I don't know how fast you're trying to get it done but @1946caddy hit the nail on the head.

    Cruise your local classifieds for whole components, they're usually cheaper than doing it piecemeal. A lot of time people just want to "clear the heavy stuff out".
    Texas Webb likes this.
  10. '29 Gizmo
    Joined: Nov 6, 2022
    Posts: 802

    '29 Gizmo
    from UK

    Went through the same thought process and ended up sticking with the mechanical brakes. Refurbished what was needed and i am happy with the performance. I also like the quirkyness of the stock system.
    El Mirage Garage and winduptoy like this.
  11. Illustrious Hector
    Joined: Jun 15, 2020
    Posts: 471

    Illustrious Hector

    Does anyone know if Richard Lacy still sells the conversion kits? We did a '37 years ago,(He also did Model A versions) it had everything ya need, and fit perfectly.
    Last edited: Feb 22, 2023
  12. Matthew Davis
    Joined: Nov 9, 2022
    Posts: 25

    Matthew Davis

    Well the drums looked ok by the ID but I put a caliper on them today and they are at best .09 thick so i guess that seals the deal on hydraulic. Time for me to get learnin'.
  13. Matthew Davis
    Joined: Nov 9, 2022
    Posts: 25

    Matthew Davis

    I'd prefer to not buy new but buying 83 year old drums online seems like a sketchy prospect.
  14. chiro
    Joined: Jun 23, 2008
    Posts: 1,187


    Original '40-'48 brakes easily adapt to a Model A. Get the Vern Tardel "Let Me Help You" booklet on Ford brakes. Lots of good information there. Not sure about the rears but the front backing plates easily adapt to the original spindles with a common adapter kit (widely available) that is a spacer for the spindle and a piston ring for the backing plate. The front backing plates will need to have the holes in the backing plate elongated to fit or better to weld them up and re-drill to fit. Use the Model A grease shields as the '40-'48 grease shields will not fit. Good original drums are hard to come by. Swap meets are your friend on this. I looked a long time for mine. If they measure out within specs try NOT to cut them if you can get away with it, unless they are out of round or deeply scored. They will often clean up with a little sandpaper and elbow grease. Cling's Aftermarket makes a really nifty setup/conversion for the master cylinder/pedal setup that uses your existing Model A pedals. Definitely use that. Important to "arc" the shoes to match the drums before install. Nobody really does this anymore, but relatively easy to do by yourself with a belt sander mounted firmly upside down on your bench. Time consuming process but matching each set of shoes to each individual drum by arcing them correctly will make your brakes work MUCH better. Use new shoes, not old NOS shoes and wear a mask.
    Last edited: Feb 24, 2023
    Papas32 likes this.
  15. murf 32
    Joined: May 30, 2013
    Posts: 71

    murf 32

    I converted my model B drums that are in my A chassis with a T body. I used off topic vw beetle wheel cylinders and master cylinder. I flipped the backing plates upside down and fitted the wheel cylinders a little bit of filing gets them to fit. You have to add a piece of metal to the back of the break shoes to get them to reach the wheel cylinder. It cost me about 100euros. I'll see if I can find a photo. Unfortunately I can't test them because the babbitts are gone in my engine. But have a great brake pedal and they grab the wheels. Tried to send ya a P.M but was unable to
  16. patterg2003
    Joined: Sep 21, 2014
    Posts: 865


  17. BlacktopScraper
    Joined: Sep 10, 2005
    Posts: 149


    Thanks Matthew for starting this post. I'm also about to start this same conversion.
  18. 29ron
    Joined: Feb 18, 2009
    Posts: 260


    I pieced my together for about $1000.
    Back Plates $200
    Wheel Cylinders $200
    Master cylinder $150
    Shoes Shoes $200
    Brake line and fittings $200
    H.A.M.B. Help
    I already had pedals.
    Time spent doing this with my son.... Priceless!

  19. Remember the '28-'35 wire wheels were designed to be supported at two levels and you need an adapter if running the '40-'48 drums. See:

    Charlie Stephens
  20. Matthew Davis
    Joined: Nov 9, 2022
    Posts: 25

    Matthew Davis

    We were intending on mechanical brakes so we picked up a nice set of '35 wires, now that we're going to juice it we may have to find a set of steel wheels instead.
  21. 31Apickup
    Joined: Nov 8, 2005
    Posts: 3,379


    Just get the support rings and you can run those wires
  22. brading
    Joined: Sep 9, 2019
    Posts: 704


    Here's an article 30's wires on 40's drums

    Attached Files:

  23. Matthew Davis
    Joined: Nov 9, 2022
    Posts: 25

    Matthew Davis

    Thanks for the article,there's been a lot of good info in this thread. I came across the spacers in my research when we were going to run mech brakes because we really wanted steel wheels, my dad especially but couldn't. We found a good deal on the wires and snagged them up. But now the debate is back on the table.
  24. El Mirage Garage
    Joined: May 26, 2021
    Posts: 135

    El Mirage Garage

    Just don’t forget that the original mechanical brakes work amazingly well if in good condition and properly adjusted. More than adequate for your typical banger, I think. Just my 2 cents…
    '29 Gizmo likes this.
  25. Matthew Davis
    Joined: Nov 9, 2022
    Posts: 25

    Matthew Davis

    Mechanical brakes were the original plan until the cost got out of hand. We were going to wait on juice brakes until we were ready to put flathead in it.

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