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Brake fluid replacement

Discussion in 'Technical Q&A' started by solly, Jun 21, 2004.

  1. solly

    solly Formula 3

    Jun 2, 2001
    1,148
    Westchester NY
    Full Name:
    Dr. Steven S.
    I recently posted about brake bleeding on a 360 Challenge and I'm now reasonably confident that I can bleed the brakes without an SD-2 unit. Thanks to all who answered.

    However, after 12-16 hours track time the fluid needs to be totaly replaced. Now even using the pressure bleeder I ordered can the fluid be totally drained and replaced without the SD-2? If so, how would the ABS system fluid get replaced? I'm still a bit unclear on turning the key one notch to get the ABS pump up and running. If it's running while I do a pressurized replacement will ABS fluid get replaced also? Since the master cylinder also serves the clutch is there anything I need to know to stay out of trouble?

    Which brake fluid is best liked for racing applications?
     
  2. ferrarifixer

    ferrarifixer F1 Veteran
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    Jul 22, 2003
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    just keep using the pressure bleeder.

    The team fleet has had all sorts of brake works done, including swapping abs units on occasion and have never needed the sd-2 once. Have never had a fluid problem of any kind.

    The 360c does not have ebd though, although I have replaced fluid on several modenas' now, without problems.
     
  3. parkerfe

    parkerfe F1 World Champ

    Sep 4, 2001
    12,887
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    Franklin E. Parker
    I like ATE SuperBlue. It has a high boiling point and the blue color makes it esay to identify any leak that may turn up.
     
  4. don_xvi

    don_xvi F1 Rookie

    Nov 1, 2003
    2,920
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    Don the 16th
    Agreed: you didn't boil any fluid in the ABS valves, so that really doesn't need to be changed.
    Also, Ford brake fluid is excellent stuff. It enjoys a good reputation among many in the amateur racing/open track community. It's what Performance Friction modelled THEIR brake fluid after! Oh, and it's cheap and readily available at your nearest Ford/Lincoln-Mercury dealer!
     
  5. Hubert

    Hubert F1 Rookie

    Jan 3, 2002
    2,642
    The Left Coast
    Something I didn't mention in the previous thread, Solly, is that some ABS systems are sealed. So, even if you wanted to, you couldn't bleed the ABS module. That said, the 1st time activate ABS, and it pulses, that will allow for fresh fluid to cycle through the module.
    I doubt you have anything to worry about.

    This question is usually one answered by cost, and frequency of replacememnt; i.e., if you want the top shelf stuff only, then Castrol SRF is the fluid, but it's ~ 60/liter and needs to be replaced often. On the cheap end, you've got Ford heavy duty, which is good, and cheap, but needs frequent replacmemnt. In my experimentation, I've found that ATE superblu and gold is the best all around fluid; namely, it's got a high WET bp (which is of paramount importance), it's readily available, it's cheap (~$10/liter) and the fact that it comes in gold and blue makes bleeding much easier; i.e., when I'm bleeding the blue, I refill with gold and I know when I've got fresh fluid in the caliper, because the color change provides a visual que.

    Hubert
     
  6. solly

    solly Formula 3

    Jun 2, 2001
    1,148
    Westchester NY
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    Dr. Steven S.
    Thanks all. i'll let you know how it turns out.
     
  7. Gary(SF)

    Gary(SF) F1 Rookie

    Oct 13, 2003
    3,637
    Los Altos Hills, CA
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    Gary B.
    Like the others who have mentioned it, I like the Ate Super Blue/Gold. Flushed the entire system in my '04 360 for track work without SD2, no problems at all.

    Gary
     
  8. brian.s

    brian.s F1 Rookie
    Professional Ferrari Technician

    Nov 3, 2003
    3,758
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    Brian
    Pentosin racing 570, a DOT 4 fluid with higher boiling point wet/dry than Ford or ATE and cheap too.
     
  9. ferrarifixer

    ferrarifixer F1 Veteran
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    Jul 22, 2003
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    Brembo racing 600. The highest boiling points of any, and Good for 6 months too.
     
  10. jeffdavison

    jeffdavison Formula 3
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    Jul 29, 2002
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    Jeffrey Davison
  11. 4i2fly

    4i2fly Formula 3

    Apr 16, 2004
    1,330
    SF, Bay Area
    Does the 360C have ABS? Is there a way to disconnect the ABS for track day on the 360? Last Sunday at the track (sears point/infinion) coming to turn 11 under heavy breaking and downshifting my pedal kept pushing up as if the ABS was being engaged even though there was no locking? Can you tell what was happening and if I disconnect the ABS does it interfere with ASR?
     
  12. ferrarifixer

    ferrarifixer F1 Veteran
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    The abs cannot be disengaged officially, but unofficially you can disable it by simply diconnecting a wheel speed sensor.

    this will display abs error on the 360C Marelli dash, but the brakes will work otherwise conventionally, albeit with a rather heavy pedal effort.

    You will be about 1 to 2 seconds per 60 slower with the abs disconnected. Trust me.

    The best laptimes in a 360C come when the driver drives "through" the ABS. Just because it starts pumping, don't stop pushing. It's only pumping to unlock the unloaded wheel, you've still got 2 or 3 wheels that can do some braking, so try to ignore the feel and just keep trusting the brakes, they won't let you down if prepped properly....360C only of course. 360M has about 3 good laps then it's toast.
     
  13. BigHead

    BigHead Formula Junior

    Oct 31, 2003
    992
    Outside of Boston
    Full Name:
    Dennis
    I wrote the following previously - remember, ABS does not require that you lock a wheel first before it engages; it senses IMMINENT lock-up and then goes to work. And I believe that ASR uses ABS wheel sensors to operate (but I could be wrong).
    ______________
    From:
    http://ferrarichat.com/forum/showthread.php?t=20398&highlight=abs

    OK, the following is just my $.02, and no disrespect is intended toward anyone. A few random points about ABS.

    First off, ABS *is* worse than locked up tires ONLY in heavy snow and gravel. Why? Because a locked up tire will cause a pile of snow or gravel to build up in front of it, thereby shortening braking distance. But if you're on ice or just packed snow, forget it. As always, the coefficient of friction for a rolling tire is greater than that of a locked tire. In other words, you'll stop in a shorter distance if your tire is not locked up. If the driver is good enough to threshold brake the car while driving on ice, god bless him/her. Me, I'll take the computers any day. In the winter, I try very hard not to trigger the ABS, because, if I'm successful, I'll have slightly shorter braking distances. But if I'm hitting the brakes hard enough to trigger ABS, then I do want the system in place, especially if I'm trying to steer as well (a locked tire cannot steer). Keep in mind that modern ABS works a lot better than older systems; with more powerful computers, cycles get much faster and the "pulses" get to be much quicker. So the effectiveness of ABS on, say, a 1989 328 will not be the same as on, say, a Challenge Stradale.

    Second, modern, four channel ABS works by calculating incipient wheel lockup, but NOT just by sensing when a wheel IS locked up, then releasing it. Common misconception. Rather, it senses the wheel rotation, compares tiny tiny tiny differences in the rate of rotation at different wheels (three channel looks at each front wheel and both back wheels as one, four channel looks at all four individually), looks at its algorithms and calculates the ideal slip angle for braking, then dances back and forth around it. ABS, when engaged, NEVER allows a wheel to lock. Rather, the wheel is question will be rotating SLOWER than the other wheels; when the difference in the rate of rotation reaches a certain point - the slip angle has increased beyond a permitted parameter - then the ABS intervenes. That intervention occurs before the slip angle reaches 100% (a locked wheel).

    So, yes, a theoretically perfect driver can brake the car at 100% of the tires combined braking force, at the maximum effective slip angle. Whereas a good ABS system will be slightly below that, because it's never at the max, but rather always just below and then just above it (not locking the wheel, BTW). But I know *I'M* not that good!

    The magic of modern ABS is that it can MODULATE EACH WHEEL INDIVIDUALLY. The driver can, at best, reduce pressure at all four wheels. As one example, at New Hampshire International Speedway, turn 9, there is a dip as I enter it. I always lock up my left rear wheel. The ABS fixes that. If I didn't have ABS, I'd either have to live with that one locked wheel (and decreased braking ability), or else reduce pressure overall to get that wheel rotating again (decreased braking ability too).

    Third, for those who believe that ABS makes cars slower on the racetrack, let me ask you a question. If ABS does make the car slower, then why has almost every sanctioning body banned ABS? Is it because they want cars to go faster? For example, ABS was in F1, but the FIA banned it because it made the cars too easy to drive - as well as faster. Teams didn't adopt ABS because they wanted to turn in SLOWER lap times, right? If the world's best and highest paid drivers run faster lap times with ABS installed in their cars, do you think you'd benefit from it too?

    Third, to address your concerns specifically, FBB, it shouldn't matter which tires you're running on the car, as the 355 Challenge ABS system isn't any different (I'm reasonably sure of this, but could be wrong). Yes, it is possible that changing to slicks does cause some problems for your car's ABS, but why not just test it? Do some practice stops, and measure your distances - street tires v. slicks, then with ABS and without.

    As for the concern about "two feet in" when you spin, it's a question that's been discussed a lot. Generally, I'd much rather AVOID SPINNING IN THE FIRST PLACE. A lot of spins are caused by ineffective trail-braking or panic-braking while cornering, and ABS might help with that. So I'd just as soon not spin. But what happens if you do spin? Well, ABS doesn't help much if you're spinning. If the tires are rotating at a PERPENDICULAR to the car, it doesn't matter whether the tire is rotating or being locked by a brake - the car will continue to spin (albeit perhaps at a different rate). Also, keep in mind that "both feet in" is pretty much bending over and saying your prayers. After all, you could just as easily be spinning directly into the wall, where ABS might have helped you send the car off in a safer direction. There isn't an easy answer to this question, IMHO, other than to say that I'd rather have the ABS to help prevent the spin in the first place, rather than worry about the potential effects AFTER I've failed miserably and the car is out of control.

    Don't believe me? Check out:
    http://www.geocities.com/nosro/abs_...he%20advantages

    Have fun on the track!

    vty,

    --Dennis
     
  14. 4i2fly

    4i2fly Formula 3

    Apr 16, 2004
    1,330
    SF, Bay Area
    Thanks for the post and I can agree with the technical description you provided, especially since in my case there is no locked wheel but there must be a difference in rotational speed between the wheels while coming into the corner that ABS engages.

    As far as having ABS in F1, I would not compare my ABS with the one Schumi used in his Ferrari. I have to disagree with this statement; while ABS helps breaking distance in a straight line, it does not help the driver while trail braking. And, often we see the F1 drivers who use brakes to their advantage to take corners to change profile or bias entering a corner.

    As an occasional track fan, I feel I could experiment with trail braking and help rotate the car into the turn, and seem ABS and trail braking don't go together.

    But, since I am that experienced, maybe the comments here by Ferrarifixer is true and 360C laps about 2s faster w/ABS than w/o, I don't know. I don't have a point of reference.

    Matt

    I have to add this as a point of reference. I had driven Sears just about a month ago and did not experience the near lock up as I did last weekend. I can only attribute this to my near slick P0s in the rear, which I was about to replace. My mechanic looked at them and said I could squeeze one more track day. Although everyone though I should get better traction with those tires, I was not and felt the car didn’t handle as well as it should. I am not sure, but I think it had to do with the tires too.
     
  15. ferrarifixer

    ferrarifixer F1 Veteran
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    Jul 22, 2003
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    4i2fly

    The abs biggest advantage is in trail braking, quite the opposite of your assumption.

    With a 360C, in a race, you can take a position under brakes from the guy in front by simply climbing up the kerb with 3 wheels in the air, plucking downshifts and heaving on the brake pedal for all you're worth.....and then defend on the exit and you're laughing!!!

    You can also left foot brake through high speed tightening corners if you like, and trim the balance with the abs/throttle as you approach the slowest part of the bend...it is totally abusable and can get you out of all sorts of trouble and encourage all the best bad habits!!

    In the wet for example, it is worth it's weight in gold.

    I don't know if you follow our www.procar.com.au racing, but Allan Simonsen recently got 3rd outright in the wet in a 360C I prep, against the GT class 620 BHP Lambo Diablo GT-R and a 650 BHP/850Nm torque Holden Monaro....

    ABS is king. Use and abuse it if you want to win....
     
  16. 4i2fly

    4i2fly Formula 3

    Apr 16, 2004
    1,330
    SF, Bay Area
    I have to admit I am no expert and don't know exatly what I was doing wrong to get the pedal kicked up to me so hard at turn 11 at Sears during downshift while all the braking was being done at the straight line. Need more practice. But what you say here makes sense. I'll give it a shot next time on the track and see how it works.
     
  17. BigTex

    BigTex Seven Time F1 World Champ
    Rossa Subscribed Owner

    Dec 6, 2002
    73,135
    Houston, Texas
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    Bubba
    Rock on, in that bad Rosso Dino car!!! :)
     

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