Suspension Brakes Brake System WTF Moment at Gingerman Raceway

Discussion in 'Tuning and Performance' started by countryboyshane, Jun 27, 2012.

  1. countryboyshane

    countryboyshane New Member

    Jul 23, 2009
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    Hello fellow track rats,

    This past Saturday at Gingerman Raceway I had a "WTF moment" when my brake pedal suddenly got very soft during a HPDE weekend. It go so bad to the point the pedal hit the floor. I've had quite a few track days to put in the books, but this was certainly a new experience.

    Background: I have a DT BBK with huge-ass 12.8" diameter rotors. I was running Hawk DTC60 pads. My instructor said my threshold braking technique was very good and I was not dragging the brakes. The last time I flushed the brake fluid was November 2011 with ATE Super Blue. Pedal had very firm feel first two 20 minutes sessions. Third session was the doozie. Flushed system again with ATE TYP 200 at the track and problem is gone.

    Is it possible that the brake fluid absorbed that much moisture to drop the boiling point this quickly? For half the time the MINI was in storage so it wasn't exposed to rain and snow. Can humidity really sap the system so quick? I have always been told that if you've changed the fluid within a year before a track event that you're good to go. Any thoughts on this? I'm thinking I'll be flushing the system before every event now with how much of a beating the front brakes take on a MINI.

    The other angle I'm looking at is the god dang ABS unit. I think it's well known that it can trap bubbles even when a power bleeder is used. I've been told locking up the wheels while going straight, and also while doing a left & right turn can help. Is there anything else I should know? I know the BMW technician's tool can activate it via the computer but I do not have money to blow on special tools.

    Sorry if this was a little long, but I'm just looking for some advice from people that have a lot more experience than me. Once you have something like this happen at 100+ MPH you don't easily forget it.
     
  2. BlimeyCabrio

    BlimeyCabrio Oscar Goldman of MINIs
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    Symptoms you're describing = boiled fluid.

    In my experience, it's ENTIRELY possible to boil fresher Super Blue than what was in your car. I've done it on the street. :eek6:

    (OK... on a mountain road that shall go unnamed, kinda the street, kinda not). :devil:

    Air in the ABS will usually manifest as generally squishy pedal at all temps, not with the symptoms you're describing. Only way I know of that happens is if you let the reservoir run dry to the outlet point while bleeding - I did that once... and it's the original reason I bought the AutoEnginuity scan tool to fix it, instead of paying the dealer to fix it. And now I have a very nice scan tool that does just about everything...

    I ALWAYS do a full bleed with fresh fluid immediately before every track day or mountain weekend. Even the time I boiled my fluid. Now I periodically use the scan tool to ensure I get fresh fluid all the way through the ABS system too, as I suspect that may have exacerbated my boiling incident. I don't do that every single bleed, perhaps every-other. I alternate between Super Blue and Type 200 (amber) to make it easier to ensure that I've gotten a full bleed. The Type 200 will still be blue when it comes out the bleeder... just not as blue as Super Blue.

    You have very good front brakes. I have a friend who is murder on what should be awesome front brakes... and has overheated them numerous times. I think I've overheated my rears... the OEM rears (even with good pads) leave something to be desired if you're pushing excellent front brakes to the limit. As I understand it, your car has less rear pad area than my first gen car... but some folks will tell me I'm crazy and that it's unpossible to get the rears that hot on a MINI. Fine. Whatever. :eek:ut:
     
  3. minimark

    minimark Well-Known Member

    Jun 24, 2009
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    Motul for the win.

    Have not boiled the fluid whilst using it.
     
  4. Crashton

    Crashton Club Coordinator

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    Yes it is possible to have brake fluid absorb moisture in that short of time. Most high performance fluids absorb moisture readily. Castol LMA is very good at not absorbing moisture, but its boiling point is not high enough. As you know the only work around is fresh fluid before each & every track weekend.

    Glad your experience did not end badly. Boiled fluid is a very scary.... :eek6:
     
  5. BThayer23

    BThayer23 Well-Known Member

    Jun 12, 2009
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    You boiled your fluid. Get rid of your Super Blue and switch to a real brake fluid. Look for something with a 600 or 660 in the name, and buy whatever you can get locally or from your favorite online distributor. I use Tilton TSR-1. Also, flush your racing brake fluid every 6 months and bleed it before every track event (flush every 2 years if you're running stock fluid on the street). Running old fluid on the track is asking for trouble.

    I am that guy that murders his brakes. VIR Full course in the summer, 95*F heat, 45mph corners, and 120mph straightaways are brutal on brakes. Out-braking the stupid Corvettes that blow by on the straights and then never let you pass - that's even harder on the brakes. Ducts, 12.2" BBK, quality rotors, and Tilton TSR-1 fluid made the difference. I'm on a 13" TCE Plus 3 kit now.
     
  6. countryboyshane

    countryboyshane New Member

    Jul 23, 2009
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    Thanks guys. I'll make sure to squiggle on my garage floor and do a bleed before a track weekend now.

    I think I'm going to switch to Motul RBF 600 based off this experience. This stuff is available locally at Detroit Tuned. Good thing he's literally down the street from me. The only thing I don't like about it is that it's sold by the 1/2L bottle and doesn't come in different colors like ATE fluid.

    Does anybody know the brake system fluid capacity for MINIs? I know I have an R56, but it can't be that different between the cars. I just want to be sure I buy enough fluid before committing to a flush.
     
  7. Nathan

    Nathan Founder

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    Two bottles is more than enough, 1 bottle is not quite enough.

    The first time you will need two bottles to do a full flush. After that if you flush often you can use 1 bottle at a time.
     
  8. BThayer23

    BThayer23 Well-Known Member

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    I used ~600 mL to flush the brakes and clutch with Dan, and ~400 mL to flush the brakes by myself. Your mileage may vary.
     
  9. agranger

    agranger MINI of the Month June 2009
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    I've had that same problem at a DE weekend... not to the extent that the pedal went to the floor, but it was quite close to that. I too was runing ATE Superblue (or Typ200 which is the same without the color). Basically, as my skill, confidence or stupidity increased, I was braking deeper and deeper, putting more and more stress on the brake system. Once I hit solo in the yellow run group or my 5-6th DE weekend, I was at the limit of my ATE fluids on my Wilwood setup.

    I upgraded to Motul for my last weekend on the track, but unfortunately I spent the entire weekend driving in the rain and my track tires never even made it onto the car so I can't report on the difference.
     
  10. agranger

    agranger MINI of the Month June 2009
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    :yesnod:
     
  11. Minidave

    Minidave Well-Known Member
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    A friend of mine who runs a Corvette in NASA events puts fresh fluid in his car before every event weekend. Period. Not just bled - replaced. He figures his life is worth more than a few bottles of brake fluid.

    You have to be able to trust your brakes, so don't cheap out - use new, race rated fluid
     
  12. countryboyshane

    countryboyshane New Member

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    Thanks for the info!
     
  13. Onramp

    Onramp Enjoy the Hiways of Life!
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    I have had really poor experience with Blue. I've used Motul 600 and flush each year in the spring, and rebuild calipers every couple of years. I couldn't find Motul this year and used Brembo 600 and had a "blue" experience. I do 10 to 12 HPDEs a season, and bleed the brakes mid season just to make sure, but Motul is the only brake fluid that works consistently for me. I usually have a student in the car as instructors usually are required to "demonstrate" during our sessions as we pay no fees here in the NW. Some of those students can be BIG folk (I'm good sized myself), and I routinely do the "6-10!-10!-10!-9-8-7- etc threshold braking to keep the brakes as cool as possible, but still - those puppies get HOT. I am switching to Motul 660, and expect the same or better performance as with the 600. Just go to Motul fluid.

    Pat
     
  14. Jan

    Jan Well-Known Member
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    The BrakeMan Fluid is even better than the Motul............
     
  15. ScottinBend

    ScottinBend Space Cowboy
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    Hi Pat!
     
  16. Minidave

    Minidave Well-Known Member
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    Maybe you need some additional cooling ducts?
     
  17. Onramp

    Onramp Enjoy the Hiways of Life!
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    Hiya, Scott!

    Dave - I'd be interested to know what you have. I tried the Mini Mania ones and rubbed the hoses off (I run 235s on the track). One of the local instructor/coach guys has a shop and we will be playing with NACA ducting and try to blow air at a better backing plate to distribute toward the hub for the rotor vents. Also may try totally different routing of the hoses, but there sure is a lot of stuff in the way...
     
  18. Onramp

    Onramp Enjoy the Hiways of Life!
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    Jan - help a dummy out! Where do you find Brake Man Fluid? Pat
     
  19. Minidave

    Minidave Well-Known Member
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  20. countryboyshane

    countryboyshane New Member

    Jul 23, 2009
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    UPDATE!

    Six month old fluid was definitely the issue. It's amazing how fast brake fluid can take in water. I was at Grattan Raceway a couple of weeks ago on a beautiful sunny Saturday. ZERO brake issues since I flushed the fluid the day before. Grattan is tougher on brakes than Gingerman and it was good to have my braking confidence back. Lesson learned!
     

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