Brakes Wheels 1st Gen Tires Mushy brake pedal

Discussion in '1st Generation: 2002–06 R50, R53 & 2004–08 R52' started by mini_racer, Jul 13, 2009.

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  1. mini_racer

    mini_racer Well-Known Member

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    I only have 20K miles on my car with just a few track events and JCW BBK, not that it matters, and my pedal is decidedly mushy.

    I noticed it back in March at a DE, and then again this past weekend at a DE. I did flush the fluid right before the DE. And then went ahead and bled them after the DE just to make sure, but the fluid looked fine and there was no aire bubbles.

    The pedal is still mushy. I am thinking the master cylinder is internally leaking, but it seems unlikely with this low mileage.

    I am thinking this will not be cheap or easy to replace. I have not consulted my Bentley yet, and not sure if I can even do it if there is some complicated procedure required to get all of the air out of the ABS system.

    Any experience out there?

    I did have the dealership check for a mushy pedal at least once during the warranty period so I might get lucky with coverage.
     
  2. mini_racer

    mini_racer Well-Known Member

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    #2 mini_racer, Jul 13, 2009
    Last edited: Jul 14, 2009
    BTW, for possible warranty coverage should I put the OEM pads and wheels back on? Oh, and I have aftermarket stainless brake lines, should I put the OEM ones back on? I guess every dealership is different, but can they be that anal about coverage?

    You know, I also have ATE Super Blue fluid in there now, and I bet they will not like that either.
     
  3. old81

    old81 Club Coordinator
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    Might be Master, could be a bubble in the lines and the bleed is not complete.

    More experience brake people should reply.

    If you put it all back to stock for possible warranty repair and the issue goes away, then it is something in the parts. Obvious, huh!

    I have seen posting about Super Blue not being liked at some dealerships, not sure if that is a myth or not.

    If it is a quality rated dot 4, brand should not matter. I would hope it a full bleed and your not mixing brands. Shudder! :shocked:

    Let us know what develops. I'm curious.
     
  4. mini_racer

    mini_racer Well-Known Member

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    Yes, I did see your posts elsewhere on the SB complaints by the dealership.

    To further implicate the Master Cylinder. Just sitting at a standstill, with the engine running, meaning poper vacuum:
    1. First pump mushy pedal.
    2. After about 5 pumps I get a pretty good pedal
    3. Hold the pedal down and after about 1 sec it starts to bleed down again.

    I can't think of anything else but the master.

    Replacing the Brake Master Cylinder does not seem too difficult, but I expect will cost around $250 for the part. And as mentioned above I do not have the means to get air properly bled through the ABS.

    Oh, and yes when I switched to SB it was a 100% switch, all SB in all of the lines.

    Just called the dealership and it seemed likely that they would cover for me. So, it looks like I will be returning everything to stock and hope for the best.

    I really could use one of those Motive pressure bleeders about now. Might as well order today.
     
  5. BThayer23

    BThayer23 Well-Known Member

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    Correct me if I'm wrong, but isn't a falling pedal at idle the classic symptom of a leaking master? If the brakes have air in the lines, it'll feel mushy when you apply pressure, but it's still a closed system and the pedal will stay hard after a few pumps. Falling pedal means open system.
     
  6. mini_racer

    mini_racer Well-Known Member

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    That is my understanding, if the pedal bleeds down while you are stopped then the seals inside the master are leaking.

    So, I am ready to go to the dealership and see if I can sweet-talk my way into warranty coverage on my stock brake system. Or maybe stock again, might be more accurate.

    Wish me luck.
     
  7. old81

    old81 Club Coordinator
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    Adding fuel to the discussion, I believe SB was implicated in eating seals. But this is not fact as I know it but BB commentary.

    Let us know what they (dealership) do for a fix.

    Good luck...
     
  8. Nathan

    Nathan Founder

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  9. mini_racer

    mini_racer Well-Known Member

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    Wow Nathan, that was very helpful. Maybe I should share those special recipes with the dealership, it might soften them up a little. :lol:
     
  10. Nathan

    Nathan Founder

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    Yeah, I know...a bit off topic but I saw that "eating seals" bit and could not resist.
     
  11. BlimeyCabrio

    BlimeyCabrio Oscar Goldman of MINIs
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  12. old81

    old81 Club Coordinator
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    Thanks Nate, I deserved that one. :D :mad5: Not really. :mad5:
     
  13. mini_racer

    mini_racer Well-Known Member

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    Some may have seen basically this update elsewhere, but here goes just to be complete.

    Ok, I had a visit to the dealership today and had some extended discussions with the tech on my mushy pedal and extended pedal travel with the bleed down after pumping a good pedal.
    He informed that it is is normal and we checked a few other MINIs on the lot for my satisfaction. The story is that some bleed down is normal and an artifact of the ABS. Specifically on the the pedal feel, it does stop some distance from the floor, if however, the pedal keeps going all the way to the floor....then it is the classic internally leaking master, but it has to go all the way to the floor.

    So, I did not get a new master cylinder today, and I am stuck with a pedal that in my view, is mushy. Grrrr! I want that good high and hard pedal too, damnit!

    So, I guess it is time to put the SST lines and the Hawk pads back on.
     
  14. scott@txwerks

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    What fluid are you using, or did I miss that discussion earlier? OEM MINI fluid isn't all that great for track work, and we've found many DOT4's that aren't as good as some other offerings, too.

    The ultimate, IMHO, is still Castrol SRF. We've used just about everything, though, including Wilwood, Ate Blue (aka Typ 200), Ate Gold, Motul RBF 600, etc. With OEM brakes, we've cooked 'em all here in the Texas summer heat on the track, though, especially at Eagles Canyon (several very hard braking zones from 100+ to ~50 MPH). Some seem to have more 'give' than others as far as pedal travel goes (e.g. in our experience, Ate fluids provide a bit squishier pedal than Wilwood or Motul, for instance).

    Our general recommendation for track junkies is that they flush at least every 6 months, more often if you do a lot of track days (and we have a few local clients that do 3-4 DE weekend EVERY month - ah, what a life!). Most tech inspections require a complete flush at least within the past 6 months.
     
  15. mini_racer

    mini_racer Well-Known Member

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    #15 mini_racer, Jul 24, 2009
    Last edited: Jul 24, 2009
    Hi Scott, thanks for chiming in here. Ok, I will have to look for Castrol SRF.
    Edit: I just did a little shopping and oh man ~$75 per liter. I might have to live with my pedal as is. :frown5:

    I had freshly flushed ATE Blue in there with my JCW brakes and SST lines.

    While I do not think I have ever really cooked/boiled the fluid, or even discolored it significantly, my nice and pretty red JCW calipers just keep getting darker and darker.
     
  16. Aeromax

    Aeromax New Member

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    I just put Valvoline Synthetic in my car yesterday. It's nothing special as brake fluid goes, only 480F dry, but it was the best thing I could find on short notice around here. The stupid crap is CLEAR! Makes for easy bleeding as you can see the change from dirty to clear, but it's impossible to fill the expansion tank and see where the level is. :lol:
     
  17. mini_racer

    mini_racer Well-Known Member

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    Yeah I know, the local auto parts stores only carry 'normal' (i.e. relatively cheap) fluid. Clear does make it very difficult to check the level even with shining a light in the side of the reservoir. The blue ATE was great in this regard.
     

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