Register now to get rid of these ads!

Hot Rods Drum brake question

Discussion in 'The Hokey Ass Message Board' started by XtechX, Oct 18, 2019.

  1. XtechX
    Joined: Jul 22, 2014
    Posts: 70

    XtechX
    Member
    from Edmore, MI

    I have built a 29 Ford model A coupe and I have 58 Buick drums with 48 Ford backing plates and hardware on the front. The rear brakes are a stock style drums from a 76 maverick. The MC and pedal is the one sold by Speedway motors for a model A/T set up/ for under the floor, it comes with a MC from a 65 mustang I believe. 6:1 pedal ratio, I think. I have the proper residual valves inline for both the front and rear.
    The problem is that the brakes are harder than a rock and don't provide much for stopping power, anyone have any thoughts on why this is?
     
  2. Torana68
    Joined: Jan 28, 2008
    Posts: 1,081

    Torana68
    ALLIANCE MEMBER
    from Australia

    Size of the m/c bore?
     
  3. XtechX
    Joined: Jul 22, 2014
    Posts: 70

    XtechX
    Member
    from Edmore, MI

  4. I'm assuming this is a new set-up and you have made sure everything is working mechanically and hydraulic wise; pull a front and rear drum and see what the shoe contact looks like.
    Maybe the shoes need to be arced.
     
    Register now to get rid of these ads!

  5. VANDENPLAS
    Joined: Dec 14, 2009
    Posts: 1,900

    VANDENPLAS
    Member

    Is your push rod adjusted correctly
    If it’s tight it won’t let the fluid return and you get a hard pedal.

    if the drums are used and heavily glazed you get the same thing.

    pull the drums and get someone to step on the pedal and see if everything is moving and returning correctly.

    see if you can see how and where the shoes are contacting the drums.
     
  6. alchemy
    Joined: Sep 27, 2002
    Posts: 14,263

    alchemy
    ALLIANCE MEMBER

    Isn't a 65 Mustang master a single reservoir? Are you sure of what you have?
     
  7. BJR
    Joined: Mar 11, 2005
    Posts: 5,823

    BJR
    Member

    Are the residual valves you added put in pointing in the correct direction? With drum drum brakes you may not need to ad residual pressure valves, the master cylinder may have them installed in the ports of the master cylinder from the factory.
     
    Model A Vette and Elcohaulic like this.
  8. Elcohaulic
    Joined: Dec 27, 2017
    Posts: 518

    Elcohaulic
    Member

    Sounds like you have pedal but its not stopping. The issue might be in the new linings not being worn in to the curve of the drums.

    A 1"bore is kind of big for manual but not unheard of.. Can you make the pedal longer to give more leverage..
     
  9. Boneyard51
    Joined: Dec 10, 2017
    Posts: 2,703

    Boneyard51
    Member

    Make sure you have the primary and secondary shoes in the right spot. That is the long shoe to the back.






    Bones
     
  10. The '48 Ford Lockheed brakes he has on the front have the long shoe in the front and the short one to the rear; unless he has some of the new repops where they made both shoes the same length. I also hear that some of those repops have hard linings.
     
    Boneyard51 likes this.
  11. Boneyard51
    Joined: Dec 10, 2017
    Posts: 2,703

    Boneyard51
    Member

    Then that may be the problem! He may have assembled like I would have! Do you know why they did that? Most of my experience was in later model drum brakes and every one I ever ran into had the long on the rear or were of equal size.





    Bones
     
    Last edited: Oct 18, 2019
  12. jimmy six
    Joined: Mar 21, 2006
    Posts: 4,648

    jimmy six
    ALLIANCE MEMBER

    MC's bore is too big. With a 6-1 pedal and a 3/4" or 7/8", it should feel like power brakes in a light car like what you have
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2020 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.