Monster MotorsportChris Nott
Results 1 to 21 of 21
  1. #1
    Whoever does not try, does not learn.

    Status
    Offline
    Join Date
    Feb 2004
    Location
    Surrey
    Posts
    191

    Brake Fluid Suggestion?

    During this weekend I’m planning on flushing the old brake fluid with new fluid as I’ve seem to have boiled the fluid again – it feels quite spongy. I’m looking for a high temp brake fluid but I don’t know what to go for and was wondering whether you guys could recommend anything? I have Black Diamond (combi range) disc with EBC Red Stuff (and it’s not a good combination!) on a standard S3 (225bhp)
    Audi S3 (52) 265bhp Revo Stage 1

  2. # ADS
    ADS
    Join Date
    Always
    Location
    Global
    Posts
    Many
     
  3. #2
    4th Gear

    Status
    Offline
    Join Date
    Oct 2006
    Location
    Manchester
    Posts
    724
    Hi Mate
    Usually just a good dot4 brake fluid is good
    You can get a dot5.1 but IIRC it needs flushing before you can use it
    Sarah

  4. #3
    Whoever does not try, does not learn.

    Status
    Offline
    Join Date
    Feb 2004
    Location
    Surrey
    Posts
    191
    What about Motul DOT 4 Racing Fluid? or is that just the same as any other DOT 4 fluid but with a fancy name?
    Audi S3 (52) 265bhp Revo Stage 1

  5. #4
    4th Gear

    Status
    Offline
    Join Date
    Oct 2006
    Location
    Manchester
    Posts
    724
    That is true
    Sarah

  6. #5
    Slipping at 3.5Krpm

    Status
    Offline
    Join Date
    Sep 2006
    Location
    Berkshire
    Posts
    1,951
    Dot 5.1 does NOT need flushing before use, DOT5 does, as DOT5 is a different type of brake fluid using different chemicals.

    However you can happily mix DOT5.1 and DOT4, and they will mix and make a fluid in the middle of the two composition wise.

    I have DOT5.1 AP racing fluid, and I also use DOT4 VW fluid, even considering track days, there is not an awful lot of difference between the two, It seems like the qualities of DOT5.1 are only displayed in harsher use and hotter atmospheric conditions than the UK temperate climate and road driving/track days.

    I found the biggest difference to be slinging EBC red and green and replacing with Ferrodo DS2500.
    <Insert meaningless geeky specs here>

  7. #6
    scib4's Avatar
    Beep-Beep!

    Status
    Offline
    Join Date
    Dec 2006
    Location
    East Kilbride
    Posts
    269
    I asked a similar question on anther forum,

    "The DOT standard includes boiling point, but also includes other factors, hence some of the best fluids don't meet DOT5.1 standard despite being much better brake fluids... And just to confuse everyone, DOT5 is completely different again for silicone based fluids

    The most important factors are dry (i.e. when the fluid is brand new) and wet (when the fluid is older and has absorbed moisture) boiling points - Castrol SRF is much better, but Motul isn't too bad either - with smaller brakes on a heavier car, your fluid temperature is going to be pretty high on track...

    All brake fluids are hugely hygroscopic (absorb water), but you could add milk and two sugars to SRF and it would still out perform all the others:

    Fluid ............................DRY....... WET
    Castrol LMA DOT 3/4......446 .......311
    Ford Heavy Duty DOT 3..550....... 290
    ATE Super Blue Racing...536........392
    ATE TYP 200 .................536........392
    Motul Racing 600 ...........585........421
    Castrol SRF ...................590........518
    Performance Friction .......550...... 284 "


    The Castrol SRF is the best as you can see from the table, but is also about twice the price of Motul Racing 600!

    I use MBF 600, and never had any problems, and that includes track days!

    Mike
    Mike




  8. #7
    4th Gear

    Status
    Offline
    Join Date
    Oct 2006
    Location
    Manchester
    Posts
    724
    Quote Originally Posted by Dave_Bayern
    Dot 5.1 does NOT need flushing before use, DOT5 does, as DOT5 is a different type of brake fluid using different chemicals.

    However you can happily mix DOT5.1 and DOT4, and they will mix and make a fluid in the middle of the two composition wise.

    I have DOT5.1 AP racing fluid, and I also use DOT4 VW fluid, even considering track days, there is not an awful lot of difference between the two, It seems like the qualities of DOT5.1 are only displayed in harsher use and hotter atmospheric conditions than the UK temperate climate and road driving/track days.

    I found the biggest difference to be slinging EBC red and green and replacing with Ferrodo DS2500.
    Hi
    Thank you for that
    I did a bit of research on this a while back , but with my old age I have forgotten which way round it was
    I must admit , I have never really liked the EBC pads
    Sarah

  9. #8
    Whoever does not try, does not learn.

    Status
    Offline
    Join Date
    Feb 2004
    Location
    Surrey
    Posts
    191
    Castrol SRF, I’ll look into that, thanks – I take it that’s DOT 4?

    As with the brake pads, there crap, although they do work great in the wet! Even the oem brakes were better!!
    Audi S3 (52) 265bhp Revo Stage 1

  10. #9
    PaulS3's Avatar
    5th Gear

    Status
    Offline
    Join Date
    Jan 2003
    Location
    UK
    Posts
    988
    ATE Dot 5.1 in mine

    have run Dot 5.1 since the Porsche brakes.
    Audi S3 Quattro Black Edition.

  11. #10
    dultanur's Avatar
    all promises, no action :)

    Status
    Offline
    Join Date
    Sep 2006
    Location
    Istanbul,Turkey
    Posts
    407
    ATE racing blue 5.1 here also...
    2000 Black S3 (Sold, then totalled) - 2008 A3 1.4T Sport

  12. #11
    Whoever does not try, does not learn.

    Status
    Offline
    Join Date
    Feb 2004
    Location
    Surrey
    Posts
    191
    Finally replaced the brake fluid with DOT 5.1, i had quite a lot of air in the system as I saw bubbles appearing while bleeding. Got one slight issue now, in order to stop the car I have to push the brake pedal all the way down. How can I adjust this, so that I can tap the brakes and the car will stop? I had replaced the brake fluid while the engine was running.
    Audi S3 (52) 265bhp Revo Stage 1

  13. #12
    dultanur's Avatar
    all promises, no action :)

    Status
    Offline
    Join Date
    Sep 2006
    Location
    Istanbul,Turkey
    Posts
    407
    i've also had this problem. i bled the brakes with the engine running, starting with the corner farthest from me working in. although its a lot better now, it's a lot softer then it was.

    i don't think i've left any air in the system as the brakes work properly without bottoming out, maybe 5.1 fluids give this softer feeling? or maybe its because of the new pads? i dont know.
    2000 Black S3 (Sold, then totalled) - 2008 A3 1.4T Sport

  14. #13
    Whoever does not try, does not learn.

    Status
    Offline
    Join Date
    Feb 2004
    Location
    Surrey
    Posts
    191
    I'm quite sure all the air has been removed from all four corners, I'll try it again with the engine off this time.
    Audi S3 (52) 265bhp Revo Stage 1

  15. #14
    dultanur's Avatar
    all promises, no action :)

    Status
    Offline
    Join Date
    Sep 2006
    Location
    Istanbul,Turkey
    Posts
    407
    someone here also suggested that the master cylinder may need to be bled, but i'm not sure how.
    2000 Black S3 (Sold, then totalled) - 2008 A3 1.4T Sport

  16. #15
    Whoever does not try, does not learn.

    Status
    Offline
    Join Date
    Feb 2004
    Location
    Surrey
    Posts
    191
    I did bleed the master cylinder as well, bit of a tight squeeze to get to though!
    I'm going to attempt bleeding the brakes via following StopTech instructions, and then see how it goes from there.
    Audi S3 (52) 265bhp Revo Stage 1

  17. #16
    PaulS3's Avatar
    5th Gear

    Status
    Offline
    Join Date
    Jan 2003
    Location
    UK
    Posts
    988
    there is also a procedure with vag-com iirc to put the abs pump in the correct state for bleeding.

    For this reason, i dont mess about with brake fluid. I pay vag specialists to do it.
    Audi S3 Quattro Black Edition.

  18. #17
    dultanur's Avatar
    all promises, no action :)

    Status
    Offline
    Join Date
    Sep 2006
    Location
    Istanbul,Turkey
    Posts
    407
    thats very wise, but over here i'm sure even the specialist won't know how to do it

    if i were in the UK, seeing how much trouble this is, and the importance of brakes (!) i would have gotten a specialist to do it.
    2000 Black S3 (Sold, then totalled) - 2008 A3 1.4T Sport

  19. #18
    Mo-S3's Avatar
    4th Gear

    Status
    Offline
    Join Date
    Jan 2003
    Location
    North West
    Posts
    703
    you shouldnt ever let the system run dry which can create air pockets in the abs system.
    Suck out the old fluid from reservoir and then fill with new stuff until you have enough in and bleed it through whilst constantly adding new fluid.
    Pumping the brake pedal is crap. Best to use a vacuum system.
    Looks like you have air in your system somewhere which needs to be removed asap. Have you bled the valve on the clutch cylinder?

  20. #19
    Mo-S3's Avatar
    4th Gear

    Status
    Offline
    Join Date
    Jan 2003
    Location
    North West
    Posts
    703
    Oh and your not meant to mix mineral and synthetic (IIRC) fluids as it can eat through the seals.

  21. #20
    Whoever does not try, does not learn.

    Status
    Offline
    Join Date
    Feb 2004
    Location
    Surrey
    Posts
    191
    I'm quite sure all air has been removed from the system, old fluid has been replaced with DOT 5.1
    Audi S3 (52) 265bhp Revo Stage 1

  22. #21
    Whoever does not try, does not learn.

    Status
    Offline
    Join Date
    Feb 2004
    Location
    Surrey
    Posts
    191
    Finally got some feel to the brakes now , I used Eezibleed Kit that i purchased from Halfords. Spent bleeding each corner about 5 times, didn't have to pump the brakes or require any assistance. It's worth buying a compression tool to do the brake bleeding
    Audi S3 (52) 265bhp Revo Stage 1

 

 

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Single Sign On provided by vBSSO

Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

Content Relevant URLs by vBSEO