Need brake help; soft pedal

Discussion in 'General Chevy & GM Tech Questions' started by kk wilson4, May 1, 2013.

  1. kk wilson4

    kk wilson4 New Member

    need help put in a new master to fix soft brake pedal no good keep going to the floor bleed them 1/2 of gallon
    of fulid all 4 no good can u help,

  2. mfleetwood

    mfleetwood Moderator

    Welcome to the Club!!!

    I moved your thread to the correct section and modified your title to fit your topic. This will help you in getting more response/opinions.

    Good Luck!
  3. Pikey

    Pikey Moderator Staff Member

    did you bench bleed it before you installed it? if not then that is most likely your issue.
  4. dsfloyd

    dsfloyd New Member

    this was my thought. The master needs to be bench bled first.
  5. K15 Blazer Guy

    K15 Blazer Guy New Member

    same issue on my truck, though i paid someone to do it... so you can imagine my frustration.

    i had 3 different shops bleed the truck, including the chevy dealership before we find a wheel clynder was cracked!
    after changing it and trying again the pedal seemed to be fixed........ now im back to square one with a mushy as hell pedal... new master, new rubber lines for the calipers and axle, and new wheel clynder...

    its obvious there is air in the system but how its creeping in perplexing... pisses me off... any ideas?
  6. dsfloyd

    dsfloyd New Member

    After this I might think that there is possible a soft spot in a brake line. so when you step on the brake the rubber hose bulges/expands. Not sure the easiest way to inspect this other than having someone put pressure on the lines and then visually inspect. Also maybe physically squeeze the lines to check for softness (similar to a radiator hose). I would think if there was somewhere that was allowing air in it would also leak fluid out.
  7. TimTom64b

    TimTom64b New Member

    What year is the truck? I'm not an expert with master cylinders but many are vacuum assisted. Be sure the all hoses are good and do not have any vacuum leaks.
  8. K15 Blazer Guy

    K15 Blazer Guy New Member

    found the problem.... rear brake line end was cracked where it plugged into the wheel cylinder
    replaced both, now it seems to be ok....... but the ABS light is now on...

    found it because there was a never ending supply of air coming out of the bleed screw while the other side was solid fluid
  9. dsfloyd

    dsfloyd New Member

    glad you found the problem as well [MENTION=54658]K15 Blazer Guy[/MENTION]. May try resetting the ABS light and see if it comes back on now that you have fixed an issue in the braking system.
  10. K15 Blazer Guy

    K15 Blazer Guy New Member

    i may just put a piece of electrical tape over the warning light lol XD
    i hate the ABS
    trucks today hardly let you control anything yourself. drive by wire. on star engine control. ABS. traction control.... all government mandated crap for people who dont know how to drive
  11. Conlan Rose

    Conlan Rose Super Moderator

    Likely its just a dirty speed sensor or one that failed which is very common on 90's GM trucks. Mine has a dead left side speed sensor so my ABS doesn't work. I'm happy I've only needed it a few times and those were times where I had done all in my power to stop safely and the ABS kicked in and did its job.

    I agree traction control(depending on what it help you do), on star dead switches, and drive by wire and dumb in many ways, but I find ABS very safe and important to modern vehicles. I don't have drive by wire I have a throttle cable that goes from the petal to the throttle plate.
  12. K15 Blazer Guy

    K15 Blazer Guy New Member

    well, i did unplug the large guage connection on the ABS pump with the truck running, but only for a few moments... i though there was air in the pump, but the dudes at the shopt, who double checked my work and bled the system, said they could not find any codes in the computer for the ABS. it just decided to come on.
    so ill reset the computer again and see, but... idk... abs only helps you in 2 senarios

    1. wet/snowy/slick roads on a down hill.... which is a ****ty senario with any braking... (my first accident actually lol)
    2. realizing you cant stop, ABS lets you steer the vehicle into a ditch rather than into someones rear bumper, cause the wheels are still rolling forward.

    overall ABS should keep your vehicle tracking straight, so the back end wont come around on you
    usually when i turn the wheel with locked brakes, it just turns into a power slide....
  13. K15 Blazer Guy

    K15 Blazer Guy New Member

    well, suddenly my ABS went out.
    this is great! the brakes feel much more responcive.
    im gonna save and accumulate a whole new line kit to delete the pump from the hydrolic system, cause its obvious the junction and distribution blocks work great to split the pressure.
    this way i can lock and slow how *I* want and not how the computor wants =)

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