Spongy Brake Pedel Help

Discussion in 'Fox 5.0 Mustang Tech' started by Slo5Oh89, Jun 17, 2013.

  1. Are these stock brakes?? Replaced Pads, Rotors, Drums, Shoes + Hardware. Around 4 years ago, It is not a daily driver so tons of life left in the pads and shoes. Had fluid flushed in 2009. Zero Issues.

    And the only change was to add MM SS hoses? Yes. But I had to do some emergency travel after I took the passenger side hose off and it was 3 weeks before I was able to install the MM passenger side hose.

    How were the brakes before the change? Were they good? Pedal was good but never really paid attention to it.

    What banjo bolts did you use? The ones supplied in the kit? Any leaks? I used the MM Banjo Bolts in the kit. Zero fluid leaks anywhere.

    If you double pump the brakes, does the pedal feel improve? Yes In other words, find a good long straight road and get up to speed and then get on the brakes. After a few seconds, do a quick release and reapply of the brakes....basically a double pump. Does the pedal feel firmer? Yes.
  2. Double pumping to get a firmer pedal usually means a few things...

    #1...air still in the lines

    #2...faulty MC

    #3...frozen caliper slide pin.

    Seeing as the problem arose after changing the hoses, I think it's #1. How quickly did you do the swap? When you removed the hoses, were the brake lines left open for a while? It's possible that air made it's way into the MC and now you need to bench bleed the MC.
  3. Yes passinger side line was off 3-4 weeks due to emergency travel.

    Does the mc have to come off for bench bleed? If so I will just get it replaced also due to age.
  4. That would probably be enough to allow air into the MC. You'll need to remove it from the car to properly bench bleed it.
  5. Ok thank you for the advice. I will move forward wit getting mc replaced.

  6. thought he said he had a shop bleed the system after he did. They should have used a power bleeder that would have pushed all the air out of the lines.

    You don't have to remove the MC from the car to bench bleed it. On the MC crack open one of the lines coming out of it, while a helper pushes the pedal down. Close the line before the helper let's the pedal come back up- just like when you do a wheel cylinder or caliper. Do this a few times until all the air is out, then repeat with the other line. Then bleed the entire system under pressure, furthest wheel cylinder/caliper from the master cylinder first.
  7. Guys thanks for all the advice I am just going to eliminate the questions and get the MC replaced and get everything bled again. I have had zero luck with the brake system so I am not going to attempt to bleed the MC myself.

    I really do want to thank everyone who has posted and helped. As always Stangnet.com has been amazing help for projects and issues.!
  8. Good, because if the MC is old, you have to make sure not to stroke the pedal any farther than it ever gets moved in its day to day life, or there's a great chance you'll gouge the seals on old untraveled bore and end up needing a new one anyway.

  9. Sorry if this is repeating, but IMO do not get a reman MC. Spend the money and get a new one from Rock Auto or one of the vendors on this site. If you were doing this yourself it wouldn't matter as much as you have a warranty, but you are paying also for the labor. No sense paying for the labor twice. Here's a list of new ones. The Dorman and Cardone's have lifetime warranties.

    CENTRIC Part # 13161001 More Info C-TEK Standard Brake Master Cylinder; C-Tek Standard
    View attachment 127627 View attachment 127628
    [​IMG] $38.79 $0.00 $38.79
    DORMAN Part # M39637 More Info {#E7SZ2140A, E9ZZ2140A, F0ZZ2140A}
    [​IMG] [​IMG] Bore: 21mm
    [​IMG] $38.79 $0.00 $38.79
    CARDONE SELECT Part # 134005 More Info New Master Cylinder
    [​IMG] [​IMG] Supplied w/Reservoir
    [​IMG] $42.79 $0.00 $42.79
    RAYBESTOS Part # MC39637 More Info Professional Grade; Bore Size=21 & 30.2mm
    [​IMG] [​IMG]
    * Stocked in outlying warehouse--shipping delayed up to 2 business days
    [​IMG] $47.79 $0.00 $47.79
    CENTRIC Part # 13061001 More Info Centric Premium
    [​IMG] [​IMG]
    [​IMG] $50.79 $0.00 $50.79
    BENDIX Part # 12196 More Info New [​IMG]
    [​IMG] [​IMG] HO engine
    [​IMG] $61.79 $0.00 $61.79
    WAGNER Part # MC117583 More Info {#F117583}
    [​IMG] [​IMG] 53/64" Bore
  10. Who knows how they did it. What the should have done is different than what they did do or if they did it properly.

    Either way, if he claims double pumping creates a firmer pedal, than that's a pretty strong indicator he still has air in the system.

    MC's are tough to bleed on the car due to the angle....sometimes if you jack the rear way up to level the MC out, you can get them to bleed on the car. I tried this once and you really have to get the rear way up to get the MC level. Pulling wheels off like this can get tricky.
  11. Guys here is the pic I said I would post. Sorry for the delay.
  12. Let me know if the caliper looks like its on the wrong side. Nothing I can do. I have had the MC replaced turned out it was failing. Then had issues with the rear brake cylinders had both replaced still spongy pedal.

    Attached Files:

  13. They're upside down. The line shouldn't be stretched to come in the bottom like that. See pics and vid for reference.

    Flip the calipers. Whaddya got to lose? 15 minutes of wrenching? Try to cap the brake line when you take it off so you don't drain the fluid out of it and the MC.


    View: http://www.youtube.com/watch?v=7zywHnpQO88
  14. Ok will do. Thanks im a idiot! haha. Thanks again
  15. well ill say this whom ever did the bleeding at the shop is a idiot to not catch the calipers being upside down or on the wrong side and i would not take them any other vehicles.
    Mustang5L5 likes this.