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Chevy brake pedal soft

Discussion in 'Truck & Equipment Repair' started by WIPensFan, Dec 4, 2010.

  1. WIPensFan

    WIPensFan PlowSite Veteran
    Messages: 3,594

    98' Chevy 4x4 extended cab 454. Guy said he slammed brakes to avoid hitting someone who pulled out on him. Said the brakes were fine for a little while, then they went real soft. I drove it a little and the brakes do work, but the pedal almost goes to the floor. Checked fluid it's good. Any guesses or maybe a diagnosis? Thanks.:help:
  2. Rc2505

    Rc2505 PlowSite.com Addict
    Messages: 1,245

    Stay on top of the fluid levels. I had an older Chevy that happened as well, and I found about a week later I blew a wheel cylinder. Just leaked a little till all of a sudden there was no pedal left.
  3. CGM Inc.

    CGM Inc. PlowSite Veteran
    Messages: 3,598

    X2, check your lines, cylinders for any leaks
  4. WIPensFan

    WIPensFan PlowSite Veteran
    Messages: 3,594

    Thanks guys, I did look for leaks in the lines, but it was right after we had been plowing so I don't know if I would see anything. The brake light is on on the dash, does that mean something in particular, other than something is wrong with the brakes?
  5. coldcoffee

    coldcoffee Senior Member
    Messages: 776

    It's a leak. Have someone pump the brakes while you check everything over. Wheel cylinders, lines, junctions/connectors and master cylinder. Try parking on some fresh snow if you don't see it, sometimes you can see the drip.
  6. WIPensFan

    WIPensFan PlowSite Veteran
    Messages: 3,594

    Thanks, that's a good idea. I'll check it again tomorrow.
  7. hydro_37

    hydro_37 PlowSite Veteran
    from iowa
    Messages: 3,790

    light usually comes on when the fluid level is low
  8. WIPensFan

    WIPensFan PlowSite Veteran
    Messages: 3,594

    Yea, I thought that might be the case, but I checked and the level is within the right range. Maybe I'll put some in and see if it helps. Thanks.
  9. Clint S

    Clint S Senior Member
    Messages: 280

    If it is not a leak you probably blew the master. If you pump it does it firm up (any way I wanted to type this it sounds dirty). Does it slowly go to the floor or quick. Does it stay on the floor. I think some vehicles have sensors that trip the light if the pedal goes down too far too.
  10. snow7899

    snow7899 Senior Member
    Messages: 234

    With that year and model, the light is coming on because of a pressure difference between the front and rear lines. Keep checking for leaks. Good luck!
  11. woodchuck2

    woodchuck2 Senior Member
    Messages: 304

    You might better just buy new wheel cylinders, brake shoes and spring kits for the rear. I am willing to bet you blew a wheel cylinder too. Chances are if one is bad the other is not for off and i am sure the springs are all rusted. Check the condition of the brake lines on the rear axle too, they may blow off when bleeding out the new cylinders.
  12. WIPensFan

    WIPensFan PlowSite Veteran
    Messages: 3,594

    Leakage! I believe it's leaking from the parts behind the fluid reservoir. Running down the back of the engine compartment. Going to dealer tomorrow.payup I would never be able to fix this, not mechanically inclined. Thanks for all the assistance guys, I'll post up what they say.
  13. Pushinsnow

    Pushinsnow Junior Member
    Messages: 29

    You have a leaking master cylinder.
  14. WIPensFan

    WIPensFan PlowSite Veteran
    Messages: 3,594

    Evidently what I thought was the leak is normal.:confused: They said a line to the rear or in the rear had blown. Oh well, you make money to spend money.:mad:
  15. M & MD Lawn

    M & MD Lawn Senior Member
    Messages: 361

    I have a 97 sierra with the 454 and I saw you said it was leaking down the back of the firewall, mine did that also and it was the hydro boost, have them check that, I will say it wasnt a cheap fix either, but fixed the problem.
  16. WIPensFan

    WIPensFan PlowSite Veteran
    Messages: 3,594

    That was replaced last year. Maybe it's old fluid from before fix.