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Does My Master Cylinder Need This Washer??

Discussion in 'Early CJ5 and CJ6 Tech' started by Roseand, May 11, 2017.

  1. May 11, 2017
    Roseand

    Roseand New Member

    Wisconsin
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    OK, so I finally got my brakes 100% done. They were working perfectly, used them probably 30 times. Then all of a sudden master cylinder piston gets jammed. Take it apart, find this. My push rod bent this washer and jammed it. I was looking at OEM schematics and they don't show a washer or retainer there... Just a snap ring. My push rod also looks a little different than the schematics I've seen.. It has a big flange on it already, so I don't understand the need for a washer anyways!
    I called dorman and the guy literally just said he can't tell me anything other than his diagrams show it uses a washer and retainer(which I can only assume is to keep the push rod straight)
    Anyone seen something like this? Pretty frustrating!
     
  2. May 11, 2017
    Roseand

    Roseand New Member

    Wisconsin
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    Can't figure out how to upload pics from my phone, shows they're too large. But anyways, it's the washer between the piston and snap ring.
     
  3. May 11, 2017
    Walt Couch

    Walt Couch sidehill Cordele, Ga. 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    The brake pedal has a return spring which will pull back the push-rod faster than the piston will return and that causes the rod to flop around if you don't have the guide washer. It is very important the push-rod travels in a flat plain to the Master cylinder both vertical and horiz.
     
  4. May 11, 2017
    Roseand

    Roseand New Member

    Wisconsin
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    I'm so confused. My push rod does not go into the piston hole far in like other ones. It has a flange on it so it just rests in the first 1/4 inch. When I bled my brakes there was little to no play between the push rod and master. Though my push rod has a flange on it and doesn't really go into the piston like others I've seen, I still need the washer??
    If that's the case, all this would have been avoided if I had a return spring? Because there's no spring on mine..
     
  5. May 11, 2017
    Focker

    Focker That's a terrible idea...What time? Staff Member

    WA
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    Look in the Help section for tips.
     
  6. May 11, 2017
    Roseand

    Roseand New Member

    Wisconsin
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    Doesn't look like I need to upload anything anyways. Looks like me screwing up was the problem! Oh well, guess sometimes you gotta learn the hard way
     
  7. May 11, 2017
    Focker

    Focker That's a terrible idea...What time? Staff Member

    WA
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    We like pics of broken things too. ;)
     
    Roseand likes this.
  8. May 11, 2017
    Roseand

    Roseand New Member

    Wisconsin
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    I'll upload it later. It was my first time working with a master cylinder... Previous experience is limited to replacing calipers and pads/rotors on my truck. Nothing This in depth. I guess I was bound to make a mistake!
     
  9. May 11, 2017
    Roseand

    Roseand New Member

    Wisconsin
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    Wait. What good is the washer doing if the push-rod flange is behind the snap ring and the washer is in between the snap ring and piston? With a spring, the push-rod would just fly back, the washer would stay in the bore and only be pushed back by the piston, not affected by the push rod in any way.
    What am I missing here?
     
  10. May 11, 2017
    Roseand

    Roseand New Member

    Wisconsin
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    Took apart my master and removed my push rod from the pedal and took a closer look and got it all figured out. With this master I got, there's a retainer that is supposed to grip onto the push rod, and the washer is there to prevent the retainer and push rod from pulling through. Just turns out that the retainer this company used, you have to remove the snap ring to remove and install it on the head of the push rod via hammer and a socket/bushing the correct ID.
     
  11. May 11, 2017
    Walt Couch

    Walt Couch sidehill Cordele, Ga. 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    That rod should never have to be driven onto the stop plate (washer). You remove the clevis and lock nut from the rod and slide the washer (stop plate) over it then re-install rubber dust shield lock nut and clevis and put it into the master cylinder then the lock ring.
     
  12. May 11, 2017
    Roseand

    Roseand New Member

    Wisconsin
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    Yeah, since I had no retainer the push rod must have popped out and hit the stop plate.
    My rod has no lock nut or clevis. Just a solid rod that pivots on the pedal. That's why most the advise I've been getting hasn't made sense.
    Looks like I'll have to get some pics after all!
     
  13. May 12, 2017
    Roseand

    Roseand New Member

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    [​IMG]
    Push rod pic
     
  14. May 12, 2017
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Looks all wrong to me. I never saw one with the flange that is by your thumb.

    But maybe it is a variant. Question I have is, is it compatible with your master cylinder piston?
     
  15. May 12, 2017
    Focker

    Focker That's a terrible idea...What time? Staff Member

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    Looks like the one that came out of my 71's dual MC.
     
  16. May 12, 2017
    Roseand

    Roseand New Member

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    The master cylinder I have looks identical to the one that was on there originally. To take the old master off I honestly didn't pay much attention.. All I did is take the rubber boot off and pull and it all came out, including the snap ring that was holding the piston in. So I honestly do not know exactly how the original was held on.
     
  17. May 12, 2017
    Walt Couch

    Walt Couch sidehill Cordele, Ga. 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Do you have swinging pedals by chance?
     
  18. May 12, 2017
    Roseand

    Roseand New Member

    Wisconsin
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    Good news! I figured out how my original master was attached. The reason it pulled out so easy is because the snap ring surface is so rusty it doesn't fit right. I do recall taking this little clip off of the push rod a while ago and it was hard to take off. Looks like my original master had this behind the snap ring, while the new one comes with just this push on retainer. I think I'm gonna use the OEM retainer..
    Thoughts?
    I have through the floor pedals.
    Old master cylinder hardware
    [​IMG]
    [​IMG]
    Old master mock up
    New master retainer
    [​IMG]
     
  19. May 12, 2017
    Walt Couch

    Walt Couch sidehill Cordele, Ga. 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Sounds like your getting there...
     
  20. May 12, 2017
    Roseand

    Roseand New Member

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    Yeah! Is the push rod supposed to be able to move up and down/side to side a little bit so it sort of centers itself when you push the pedal down? Because this one does have a little play but so did the original. It looks like some of the pushrods go into the hole of the piston making it so the rod travels perfectly straight. The end of my push rod has that flange which ends up touching the outside of the piston hole so it's able to move a bit. If it doesn't matter I'll leave it, otherwise I'm sure I can find a way to tighten it up.
     
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