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Technical Brake question/theory

Discussion in 'The Hokey Ass Message Board' started by samdjr74, Jun 8, 2020.

  1. rusty valley
    Joined: Oct 25, 2014
    Posts: 3,883

    rusty valley
    Member

    i know, i am a jerk, but i always wonder why anyone thinks they need disk brakes in the first place. by 58 the OEM brakes were more than adequate. ever drive a model T ?
     
    bobss396 likes this.
  2. deucemac
    Joined: Aug 31, 2008
    Posts: 1,483

    deucemac
    Member

    the return springs move the shoes back from the drum into a running clearance position. The residual pressure valve is usually a 10 pound unit. It holds enough pressure to ensure that the lips on the rubber cups in the wheel cylinders stay tight against the wheel cylinder bore to prevent leakage. Rum brake shoes should NEVER ride on the drum face when not applied.
     
    57 Fargo likes this.
  3. I like discs up front so my car stops as well as new cars I share the road with. Discs in the rear complicate matters and can be hard to sort out.
     
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  4. samdjr74
    Joined: Feb 8, 2016
    Posts: 170

    samdjr74

    And I do agree with this, however, the condition of my rear drums became a safety issue. Because of the hub/drum assembly getting replacement drums was costly if they could be found. There's one dealer on line who sells used assemblies for $500 each. That doesn't include shoes, springs, wheel cylinders, etc. I know those parts aren't expensive but it needs to be factored in. If parts were readily available at a decent price, then I would have gone with a stock drum set up in the rear.
     
  5. Yeah, what he said! The car companies only went to disc to be able to charge more money! :mad::mad::mad::mad:


    Ben
     
  6. jimmy six
    Joined: Mar 21, 2006
    Posts: 14,798

    jimmy six
    ALLIANCE MEMBER

    It’s possible that a complete rear end change would have been easier eliminating the tapered hub drums and dual wheel cylinders. Your into it a lot now but it’s always a consideration.
     
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  7. squirrel
    Joined: Sep 23, 2004
    Posts: 55,934

    squirrel
    Member

    And we still have not actually checked pedal free play.
     
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  8. samdjr74
    Joined: Feb 8, 2016
    Posts: 170

    samdjr74

    I will check it this week or this weekend, work is a little crazy right now
     
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  9. squirrel
    Joined: Sep 23, 2004
    Posts: 55,934

    squirrel
    Member

    No problem...I just think it's interesting that we keep going off on these tangents about your brake system, yet we still don't know if the easiest thing there is to fix, and most likely cause of the problem, is what's really wrong with it.
     
  10. samdjr74
    Joined: Feb 8, 2016
    Posts: 170

    samdjr74

    Exactly and I'm on board with looking at the free play. I just need time now, which is in short supply until the weekend. I work in an industry that is overly busy because of the current health crisis. But this weekend I should have enough time to check everything out.
     
  11. gimpyshotrods
    Joined: May 20, 2009
    Posts: 23,264

    gimpyshotrods
    ALLIANCE MEMBER

    Uh, no. Disc brakes are actually cheaper to manufacture (in addition to working WAY better).

    I work for GM. As the kids say, I have the receipts.
     
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  12. squirrel
    Joined: Sep 23, 2004
    Posts: 55,934

    squirrel
    Member

    I wonder why they switched back to drums on the full size trucks in the mid 2000s? :)
     
    Flat Six Fix likes this.
  13. gimpyshotrods
    Joined: May 20, 2009
    Posts: 23,264

    gimpyshotrods
    ALLIANCE MEMBER

    [Citation needed]
     
  14. squirrel
    Joined: Sep 23, 2004
    Posts: 55,934

    squirrel
    Member

    wife's 99 silverado with rear disk, and her 2008 and 2012 silverados with rear drums.

    They have to include a drum brake inside the disk brake for a parking brake, so I'd think the cost is close. But pickups really don't need rear disk brakes....maybe they figured it out....
     
  15. Arominus
    Joined: Feb 2, 2011
    Posts: 394

    Arominus
    Member

    the AAJ kit has a history of this issue over on the forward look. Good luck.
     
  16. samdjr74
    Joined: Feb 8, 2016
    Posts: 170

    samdjr74

    Never heard that before, nor have i ever had a problem with the AAJ front set up
     
  17. I could have gone with front drums with my car, but it was missing almost everything. A other option in your case would be using another complete drum rear, but that brings it's own complication.
     
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  18. Discs work better wet over drums. They are easier to work on, mechanics that can work on drums are a dying breed. Less moving parts as well.

    Like a stock car class, things escalate. If one maker goes to rear discs, others follow and consumers will want the better product.
     
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  19. 54vicky
    Joined: Dec 13, 2011
    Posts: 1,599

    54vicky
    Member

    I would think this is worth taking a few minutes to check.another thought when is NEW new meaning no flaws perfect out of the box= master fked yes trudy it does happen with asian products
     
  20. gimpyshotrods
    Joined: May 20, 2009
    Posts: 23,264

    gimpyshotrods
    ALLIANCE MEMBER

    Happens with US made products, too.

    We regularly have to reject entire shipments.
     
  21. samdjr74
    Joined: Feb 8, 2016
    Posts: 170

    samdjr74

    Just to close this up, the push rod needed to be adjusted, I think the heat related lock and firm pedal was confusing me as I had this once before and the brakes always dragged. Once I readjusted the pedal, gave it a little free play, the brakes work fine now.

    Thanks all.
     
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  22. squirrel
    Joined: Sep 23, 2004
    Posts: 55,934

    squirrel
    Member

    Seems hardly worth 82 posts
     
  23. brokedownbiker
    Joined: Jun 7, 2016
    Posts: 651

    brokedownbiker
    ALLIANCE MEMBER

    Especially since the correct diagnosis was given in the 2nd sentence of the first response. SMH
     
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  24. 54vicky
    Joined: Dec 13, 2011
    Posts: 1,599

    54vicky
    Member

    some people only learn by learning.ask for advice if it makes sense ignore it.
     
  25. And the first sentence of the second reply! ;)
     
  26. Happydaze
    Joined: Aug 21, 2009
    Posts: 1,903

    Happydaze
    ALLIANCE MEMBER

    What would be the fun in the answer to the problem being always found within the first few response? What would we do with the time saved? Rhetorical questions! :)

    Chris
     
  27. First post,

    Every single damn time (well 99%) that there is some mysterious problem here that defines all logic and borders on the realm of mysticism It is bad methods or false assumptions at the roots.
    I’m telling you guys, brake fluid is getting smarter and smarter.
     
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  28. scrappybunch
    Joined: Nov 16, 2011
    Posts: 412

    scrappybunch
    Member
    from nj

    Out smarted by brake fluid again
     
    Tman and 31Vicky with a hemi like this.
  29. GeneBob
    Joined: Apr 25, 2017
    Posts: 72

    GeneBob
    Member

    I skimmed this series of posts and wanted to suggest something that may have been stated but here goes: You may have too much clearance in your pedal to MC linkage. If your pedal returns to the top of travel and the pushrod for the MC goes off center in the MC piston, you have now created the condition that would keep the piston from returning all the way and result in what you are experiencing. You definitely MUST have a small amount of play when the pedal returns to its top of travel BUT if it is too much, the pushrod will go off center, then you adjust to this "off center" condition and the next time you press the pedal the pushrod slips back to the center and you lose half of your brake pedal travel. You may want to verify that this did not happen.
    Take Care.
     
    Tman likes this.
  30. Baumi
    Joined: Jan 28, 2003
    Posts: 3,043

    Baumi
    ALLIANCE MEMBER

    Hahahaa, my belly hurts from laughing!:D
    Maybe it´s the other way ´round! " Us" are getting uneducated´er ( nicest word I could come up with ):D
     
    Tman likes this.

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