Abs Brake Fluid Change

Discussion in 'Speed Triple' started by Alan Gilbert, Dec 3, 2021.

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  1. Alan Gilbert

    Alan Gilbert Senior Member

    Nov 22, 2018
    276
    113
    Lincolnshire, UK
    #21 Alan Gilbert, Dec 7, 2021
    Last edited: Dec 10, 2021
    Front brakes finished . . . a check of all cover bolts now to ensure they're good . . .working from front to back and so rear brakes to do a little later.

    DealerTool had me a little confused as there is a tab labeled ABS - when opened, everything is greyed out except the option to "Connect To ABS" - clicking on "connect" automatically gives some basic data on the ABS including any error codes, of which there were none. Two more tabs now become highlighted - clear codes and bleed ABS.
    I clicked on bleed ABS and after about 5 seconds of so, the solenoid fired off. There was no tab to stop it and so a momentary panic set in. It seems that DealerTool runs the ABS for 20 seconds and then turns it off. Initially, I thought it cycled repeatedly because I pressed the “bleed ABS tab” more than once in an attempt to stop the procedure and it paused before repeating. The process seemed to work well enough if a little confusing to start with.
    I've had a rethink on the leak . . . . it's possible the bleed nipple might not be leaking . . . if you look at the design of these things, it's likely that after bleeding, there's a residual reservoir above the nipple seat where fluid could continue to wick up the threads and this is likely to happen for a while, even after the inside of the nipple has been blotted dry. I will keep an eye on it for now as it will be a few days at least before I reinstall the pads and front wheel. One thing that seems likely . . . if the seat of the nipple is leaking and I squeeze the front brake with any amount of force, any fluid released past the seat should work it's way through the bleed hole and up inside the nipple as an easier path than going up the threads - maybe I will check by applying a decent force to the front brake but with a stem of tissue stuffed down the nipple and see if it picks up any fluid.

    Capture2.JPG

    Anyway . . all done for now - only two things I failed to mention were . . . .

    1. Bike was as dead as a dodo again when I attempted to power up - a new CR2032 solved the issue and so for now at least, I am storing the key "sans" battery and I guess it's a case of contacting the dealer for a possible goodwill gesture on the fob or forking out for a new one - watch this space and

    2. I checked the manual I have for the 2011-2016 Speed Triple R. (although this manual also covers the Speed Triple for the same period) The manual describes bleeding the brakes and specifies torques of
    front bleed nipple 6nm
    Master Cylinder Nipple 6nm
    for both models.
    The 11-16 Speed Triple has different calipers to the 11-16 R which uses the same as on the RS but the bleed procedure is described only once to cover both bikes.
    Both bikes use the same master cylinder bleed nipple as the RS - part number T2025916 and specify 6nm for the torque setting.
    Now I'm a little concerned but I suspect the 11-16 Speed Triple and R should require 6nm for the caliper and the 6nm for the master cylinder nipple is an error. My gut feeling is still that the RS manual is correct at 8nm/14nm simply because the thread size of T2025916 is significantly more than the caliper nipples and so surely calls for a higher torque. It seems likely that Triumph have upped the torque for the front caliper nipple but left the typos in the specifications and exploded view. It's a guess but the difference between 6nm and 14nm is a worrying dilemma.
     
  2. Hubaxe

    Hubaxe Good moaning! aka Mr Wordsalad :)
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    Mar 25, 2020
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    Aix Les bains - French Alps
    The best improvement I found to bleed brakes is the installation of Stahlbus bleeders on the caliper.
    About the ABS, the best maintenance tip is to use the ABS time to time intentionally, just to have the fluid circulate in the system.

    Nice thread! Thanks Alan!
     
  3. Alan Gilbert

    Alan Gilbert Senior Member

    Nov 22, 2018
    276
    113
    Lincolnshire, UK
    #23 Alan Gilbert, Dec 20, 2021
    Last edited: Dec 20, 2021
    It seems leaky nipples is a common problem on Brembo calipers - I spent hours reading through posts from various different forums . . . especially Ducati forums.
    Much of the advice and guidance given to the OPs in each case does appear to be misinformed - the most common of which is to use PTFE tape on the nipple threads. This would appear to be totally pointless because if the seat is truly leaking but the threads blocked by PTFE tape, any leaking fluid will merely rise up through the centre of the nipple and out of the bleed hole, as it would without the PTFE tape. Despite this, many folks appear to confirm this action worked and did indeed cure their problem and this caused me to conclude what is actually going on here (as confirmed by a previous poster on this thread) . . . . . . .

    After bleeding the brakes, residual fluid remains in the hollow centre of the nipple and this simply passes through the hole in the bottom of the nipple and wicks up the threads. This is what caused my first overnight leak and resulted in a couple of drops of fluid on the floor under the caliper.
    After this, I dried out the inner core of the nipple by blotting it but subsequently, I still experienced another small "leak" down the side of the caliper which was insufficient to drip onto the floor.
    I then placed a collar of tissue paper around the nipple and squashed it down using the rubber nipple cap so that any leakage would be blotted up by the tissue. I had the smallest of damp patches on the tissue which recurred 2-3 times and I concluded this was due to residual fluid within the threads simply wicking its way up by capilliary action. This was confirmed by strapping a bunjee to the front brake lever and leaving the thing under pressure all day whilst I worked on other parts of the bike . . . . . no fluid expressed, despite the pressure in the caliper being massively high - nothing leaked out.
    I have never had this problem before on Nissin calipers but of course, the issue could be down to the quality of thread used and/or type of nipple. If the nipple used a tapered thread, it would more likely be self-sealing and not allow any subsequent creep of fluid. The fact remains, leaky Brembo nipples appear in the forums all too regularly and although I suspect many of them aren't truly leaking, owners often resort to PTFE tape, new nipples, replacement calipers and heaven forbid, tightening the nipple well beyond spec, only to report the problem persists. Needless to say, never tighten the nipple beyond spec and be sure to check your issue is a real leak and not merely caused by the seepage of residual fluid up the parallel threads of the nipple.
    I would suggest that following a fluid change, blot any residual fluid from the centre of the nipple, before then drying the exposed threads and very carefully where they connect with the caliper. After all "leaks" have stopped, place a "collar" of tissue around the nipple, held down with the rubber cap and then use a bungee to squeeze the brake lever for a couple of hours to check for leaks. Do bear in mind that mine continued to produce very small spots of fluid on a tissue collar for at least 2-3 days before finally stopping and so perhaps conduct the pressure test after this has stopped so that you don't confuse any such deposits as being due to a leak caused by squeezing the brake lever.

    Finally, I remain unhappy about the contradictions in the manual and have today written an email to Triumph to verify the correct torque settings for the front brake bleed nipple and master cylinder . . . . see below -

    Dear Sirs,


    I am intending to change the brake fluid on my Speed Triple RS and would like your guidance on a "safety critical" error which appears in your online service manual for my model.. . . .


    Under the Section titled Brakes> Exploded view> Front Brake Master Cylinder, the drawing clearly shows the master cylinder bleed nipple torque as 6nm

    Under the Section titeld Torque Wrench Settings> Front Brakes, the table of torque settings clearly shows the Front brake calliper bleed screw torque as 6nm


    In contradiction of the above, there is a description for bleeding the front brakes within the service manual and this procedure documents completely different torque settings . . . .


    Under the Section titled Brakes> Braking System Maintenance and Safety> Bleeding the Front Brakes, Renewing Brake Fluid, the service manual calls for the front brake calliper bleed nipple to be tightened to 8nm but even more worryingly, a torque of 14nm for the master cylinder nipple - a full 8nm more than shown on the Exploded View.


    Clearly the above is safety critical because either setting could result in an improperly secured bleed nipple or the possibility of stripping the thread in the master cylinder.


    For reference purposes, I referenced the above against the same task for the 2011-2016 Speed Triple S which has the identical front Brembo brakes, master cylinder and bleed nipples and all of which have the same part numbers as my bike as shown on the World Of Triumph Website. This manual shows ALL the above torque settings as 6nm, both in the "Exploded View", torque settings tables and procedural description in the text.


    I would be very grateful if you could confirm the correct torque settings for my bike for the front brake caliper and Front master cylinder caliper so that I may carry out the required maintenance correctly and safely.


    Many thanks in advance for your help with this


    Kind Regards


    Alan Gilbert
     
  4. Col_C

    Col_C I can't re...Member
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    Aug 5, 2015
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    Cornwall
    A very thorough review Alan :)
    I'll add my 2d
    Firstly a fundamental of bleed nipples is that it is a metal to metal seal formed by the cone seating on the edge created by the port drilling (as can be seen in the picture you posted earlier). For a good seal there must be (very) slight material deformation of one or both parts to create that perfect seal. So if you inspect a used nipple cone you should see a slight witness mark all around where it has sealed.
    So reasons for bad sealing could be -
    1. debris contamination
    2. cone and bore not concentric or damaged
    3. insufficient axial load to generate that deformation
    BTW your suggestion of incorporating a taper thread would not work as both the cone seal and taper thread by design require set depths on assembly, manufacturing tolerances would never coincide and one would always prevent the other from sealing properly.
    As regards why Brembo are more troublesome (if indeed they are) I doubt whether (2) is likely with their revered reputation, (3) is more likely, possibly due to materials of a higher yield strength being used and/or incorrect torque settings being used.
    The torque setting is a means to generate the axial force required to provide that slight deformation and perfect seal, and there in lies the clue as to why some have said PTFE tape has solved their problem. Brake fluid is not a great lubricant, PTFE is, so for the same torque the axial load will likely be higher if the nipple is wrapped in PTFE tape. Greasing the thread would have a similar effect.
    Personally I've always gone by "feel", never had a leak and never stripped a thread (in that context), although not recommended for the inexperienced or heavy handed. May be next time I flush the brakes I'll get the torque wrench out and check what I'm actually generating. :)
     
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  5. Alan Gilbert

    Alan Gilbert Senior Member

    Nov 22, 2018
    276
    113
    Lincolnshire, UK
    #25 Alan Gilbert, Dec 20, 2021
    Last edited: Dec 24, 2021
    Good point about the tapered nipple - I hadn’t thought that through properly.
    Just done the rear brake and the “leaky”threads were really obvious. . . . I was using clear silicone tubing and had just finished bleeding but with the tubing still attached and full of brake fluid. I noticed bubbles forming within the top of the nipple and then breaking free and rising up the tube. There is only one place the air was coming from and despite the nipple being torqued down, the column of brake fluid in the bleed tube was drawing air in via the threads and was doing so very easily!

    Have had a totally useless reply from Triumph re my email. They confirmed the caliper nipple torque to be 6nm and attached a copy of the torque tables from the manual. . . . duh!! I already had that.
    They ignored my query re the master cylinder nipple and so I threw it all back at them and gave them a second chance and so essentially, still waiting to hear . . . .
     
  6. Alan Gilbert

    Alan Gilbert Senior Member

    Nov 22, 2018
    276
    113
    Lincolnshire, UK
    OK . . . this will be my last post to conclude this subject and there are several comments
    1. Triumph came back to me but this time confirmed they had involved their Technical services team and the correct torque figures for the front brakes are 8nm for the front caliper (not 6nm as I was previously told) but more importantly - 14nm for the master cylinder. The thread on the latter is clearly much bigger (I suspect 10mm as opposed to 7-8mm for the caliper) and so not surprising . Most master cylinders don't use a different thread size but on the Speed Triple it is quite obvious. I have edited my first post to remove this ambiguity for anyone who reads this thread in future
    2. I had a Eureka moment and placed my "high pressure" bicycle pump over the caliper nipples and it was a perfect fit. (Not the screw on Schrader type but the push on jobbies that most racing cycles have)
    I held it down on the nipple and pumped away - the air hissing out of the threads of the nipple was very obvious, along with various sputterings from the brake fluid contained therein and which then soaked into the tissue which I had around the neck of the nipple and pressed into place with the attaching ring of the nipples rubber cap.
    I was really rather surprised at how the air could so easily make its way up the tightened threads of the nipple. Anyway . . . . my procedure moving forwards for bleeding brakes will be
    1. Bleed the brakes in the normal way as per the manual.
    2. Tighten bleed nipple to recommended torque.
    3. Twist up a length of tissue paper and insert several times into the core of the nipple in order to soak up any residual fluid present
    4. Remove the nipple cover - place a tissue collar around the nipple and hold it down with the rubber nipple cover back in place.
    5. Give enough pumps onto the nipple to blow any fluid out of the threads and continue until no further brake fluid is expelled.
    6. Clamp the brake lever with a bungee for a couple of hours and repeat 5. If more brake fluid is expelled, there is a leak and so remove the nipple, clean/inspect the seat for damage and replace if necessary.
    7. Having carried out the above and finding a leak still remains, Increase the tightening torque by no more than 1-2 nm max.
    8. If leak persists . . . . PANIC!!

    It is interesting to note that the rear brake is Nissin and yet I had the same issue with fluid retention in the threads of the nipple and the quantity which was expelled using the bicycle pump was surprising.
    There was no need to remove the caliper for simple bleeding, however, as it was part of winter maintenance, I wanted to clean it up, clean and grease the pistons with red rubber grease and also push the pistons fully in and block them whilst bleeding to ensure that I achieved a total bleed and didn't leave stagnant old fluid behind the pistons.
    It is interesting to note that my front pads are brand new EBCs and removing the pads and pushing the pistons fully back with "made to measure" blocks of wood, expels an amount of fluid not much less than the contents of the master cylinder reservoir. As mentioned earlier, no mention is made of this technique in the Triumph Service manual but my BMW S1000RR manuals specifically demands it (Brembos but not the same caliper) in order to prevent the new fluid from coming straight down the lines and out of the nipples, whilst leaving the old stuff behind the pistons. I will continue to do this because in truth, it isn't much hassle and necessary or not, I will know for sure the job's been done as best as it can

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