Yoiks !.... No Brakes !!!

Discussion in 'Troubleshooting & Diagnosis' started by Kasey74, Mar 1, 2008.

  1. Kasey74

    Kasey74 Veteran Member Lifetime Gold Member

    Last night i was driving home in my 1983 Chev work van, and the brake problem finally got "bad'... no brakes. For about a week, the brakes had been getting a little mushy, and brake fluid was dripping down the the booster, where the master cyl bolts on. I was hoping the brakes would last til the weekend, so i would have time to fix them. It got to the point yesterday, where i had to pump the brakes to get them to work, even with the fluid topped up in the master cyl. Anybody had this problem before ? I took apart the master cyl, honed it out with a brake cyl hone, and put new seals in it. I also found that the booster had been drawing in some of the brake fluid that had been dripping out the back of the master cyl, due to a bit of rust between the rubber seal and the booster where the rod sticks out... did the brake fluid wreck the booster ? I bench bled the master cyl, bolted it back on, and then pushed the brake caliper pistons back all the way, to try and force any air in the brake lines up to the master cyl resevoir. The brakes still are'nt working very good, though. I'll try bleeding them all the way through the calipers, and and see if that helps, but has anybody had a booster go bad before ? Right now, the pedal just sink's to the floor on the first pump on the brake pedal, and after pumping it a a couple times, it feels like the the pedal has some resistance behind it... but then after waiting a few seconds and pushing the pedal again, it sinks right back to the floor ! The front calipers, rear brakes, and lines are'nt leaking. Is the booster shot, or do i need to buy a new master cyl ?
  2. spoonLT1355

    spoonLT1355 Veteran Member Lifetime Gold Member

    Mar 1, 2003
    Rockledge Pa
    sounds like air in the system, if the booster went bad, the pedal would be VERY hard to push down.

    open all the bleeders and keep the master topped off. let them go for a few minutes, then close them off. See what you have then.

    If you still have no pedal, consider getting a new master. They are cheap enough.
  3. RacingRob

    RacingRob Veteran Member

    Aug 14, 2001
    Yorktown Heights, NY
    When you remove the master cylinder you have to bleed all 4 wheels.

  4. mnz28

    mnz28 Veteran Member

    Apr 3, 2004
    Yes bleed all the brakes. Do yourself a favor and start spraying down the bleeders with liquid wrench or your fav product.
  5. 79camaro2001

    79camaro2001 Veteran Member Lifetime Gold Member

    May 4, 2003
    Monroeville, PA
    sounds like air in the system to me. Do you hear air rushing anywhere? Usually if you hear a air rushing sound when you push the pedal that means the fluid is getting by the seal and it is a bad master cylinder.
  6. Kasey74

    Kasey74 Veteran Member Lifetime Gold Member

    It ended up being the rear seal on the master cyl that started leaking, so the MC got replaced. The brake booster actually started to draw brake fluid into it when the pedal was released, and it was about 1/4 full of brake fluid, so i replaced that as well. Bled all 4 corners, and the brakes work great now. Thanks for the help... :bowtie:

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