Spongy brakes after bleeding?

Discussion in '80-Series Tech' started by Pete483, Oct 25, 2005.

  1. Pete483

    Pete483

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    I finally got all the stuff I needed to finish my brakes. During this project I put on SS lines, new front calipers, I rebuilt the rears, and new pads all around. I bled the master cylinder, then did about five iterations with my motive bleeder until there were no bubbles and the fluid was new and clean. I also let the car sit about a half hour halfway through.

    Upon turning on the car, I had a spongy pedal so I did another couple iterations with the motive and then a couple the old fashioned two-man way. Turned on the car and the pedal is still mushy.

    All I can think that may have caused this is that I screwed up bleeding the master cylinder. I followed the FSM, but had never done this before since I have never had the reservior completely empty. Could that be my problem, or something else?? :confused:
     
  2. offroadkid

    offroadkid

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    Not at all trying to saying you don't know what you're doing, but did you go start at the right rear, then left rear, then right front, then left front when bleeding the lines?
     
  3. -Spike-

    -Spike-

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    Same problem with mine, I'll keep an eye out here, if you find a solution elsewhere post it up.

    -Spike
     
  4. Pete483

    Pete483

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    I did the order as per FSM, plus did the LSPV a few extra times as well.
     
  5. flintknapper

    flintknapper

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    When I bled mine, I started with the LSPV, then the right rear. Revisited the LSPV several more times and found more air collecting there.

    Finally got a hard pedal, but in my experience the brake system on an 80 does not bleed easily.

    Naturally, when replacing a Master Cylinder (or if it runs dry), you'll want to start there first and make double darn sure its bubble free.
     
  6. hkimsoft

    hkimsoft

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    I have exact same problem... if you find solution, please post 'em.
     
  7. Cobra Jet

    Cobra Jet

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    has there been any updates to this thread (or has anyone who originally posted in this thread come to a solution)? If there was a solution or the mushy pedal syndrome was fixed - what was the fix or procedure?

    :idea:
     
  8. use4low

    use4low

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    please:confused:
     
  9. Bear80

    Bear80

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    I've been fighting the same issue with my mini truck. The bottom line is that there is air in the system and it is a bitch to get out. Even with a power bleeder at 40 psi I still have air and a soft pedal. I'm loosing friends because I wear out their legs having them pump for me. Neither method has worked. I would like to know how they bleed the system at the factory.
     
  10. Pete483

    Pete483

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    I'm not sure if I've gotten used to them, or if they've firmed up a bit somehow, but they aren't too bad now. I've been meaning to bleed them a little more some weekend, but haven't gotten around to it. Either way, they are way way better than they were before I changed pads and put in the stainless braided lines, so I am happy.
     
  11. rockclmbr

    rockclmbr

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    All, please have a look at this:

    https://forum.ih8mud.com/showthread.php?t=78824

    It must be air in the lines as I've replaced almost everything brake related. One thought came across my head yesterday was the vacuum booster. If this isn't working properly will the brakes appear spongy or just firm like when the vehicle isn't running? I'd hate to take it to a shop and pay for bleeding when I know they don't have any special technique or experience this board can't offer.
     
  12. MH_Stevens

    MH_Stevens

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    The vacuum boster tests are simple and done in a minuet. See the FSM. Mine has similar spongy and I have replaced back pads and will bleed again but this time i will do the master first.
     
  13. Bruneti

    Bruneti

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    Read all of this referenced thread carefully, and you'll find mention of bleeding the brakes with the engine running. The vacuum booster can't maintain vaccum without the engine runnning. It will be depleted quickly. Try this method and see if that helps.
     
  14. robjam

    robjam

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    I used SpeedBleeders on my '92. It was quite effortless and I did not have any air issues. It was great for flushing out all the old fluid as well.
    Hoping you find a fix, but it sure sounds like air.

    I was able to push so much fluid through with the speedbleeders that any air must have been forced out quickly and not left lingering.

    Good luck !
     
  15. fzj80kidpen

    fzj80kidpen

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    Unfortunately mine peedle will slowly compress all the way to the floor with the truck off. This means ?
     
  16. Darwood

    Darwood

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    your master cylinder most likely has bad seals.
     
  17. MH_Stevens

    MH_Stevens

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    I just put on new back pads and re-bled but this time I bleed the FSM way, which is different from the single pump down, hold, open, close release method. Also I opened the bleed nipple on each break assembly so when I compressed the calipers the old oil escaped onto the floor and was not forced back into the master or reservoir. I really believe this gave a much more effective bleed and my breaks are now fine.
     
  18. Bryan E.

    Bryan E.

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    Speed Bleeders


    That's good to hear that the speed bleeders work. After bleeding my brakes last time, I bought a set but haven't installed them yet. One of the old bleeders was defective, but I got it done and decided these would be a nice upgrade.
     
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