Flushing ABS Brakes / Stopping Fluid Boil

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by ciedema, Aug 23, 2013.

  1. ciedema

    ciedema мотоциклист

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    I routinely find myself boiling brake fluid, I did this on my 950 and now my 990. I really need pump some fresh fluid through the system as it happened often enough the fluid is well past it. So it flushing the ABS brakes the same as doing non ABS ones? (ie keeping adding fluid to the master cylinder while pumping it through the slave).

    So on to my other question, I tend to trail brake a lot, especially when riding off road and can boil the brakes pretty quickly if I am not careful. I doubt that I am the only one who experiences this. So have other come up with a solution to stop this from happening?
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  2. folknride

    folknride Old Adventurer

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    I think I noticed that Slavens is selling a brake fluid radiator/cooler thingy.

    BTW I just bled the rear in the normal way and it worked, but I was really careful not to let the level fall to low - if you got air in the ABS circuit - who knows?
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  3. tkent02

    tkent02 Long timer

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    I replace the fluid and bleed them normally, then go out and skid all over the place the get the anti skid moving fluid around inside and bleed it again.

    Don't know if it gets it all but it's fun.
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  4. Dusty

    Dusty Long timer

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    Yep you can bleed normally, its nice to have a big jug of fluid, as you know its a long push, master to the pump then the caliper. I always did the caliper furthest from the master first. I don't think i could do it alone, my arms not long enough.

    I have been using a good vacuum that hooks to the compressor to do it the the last few years, and i can do it on my own.

    As for the rear its just seems like a small reservoir and heats up fast.
    On the rear i took off the abs line to it and plugged the pump and got a hose from an S model. I like the abs on the front only, works well for me.
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  5. ciedema

    ciedema мотоциклист

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  6. Orangecicle

    Orangecicle On a "Quest"

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    A KTM mechanic I trust had me remove the rear caliper and flip it upside to start the bleed process. Oil floats on water, so water will sink to the bottom of the upside-down caliper, and you get all of the water out that way.

    I lost my rear coming down off of Mt. Evans in Colorado a couple years ago. I was trailing a slow Range Rover, and engine braking wasn't cutting it. I was on pavement, so I could use the front. After the back brake started coming back a little, I started alternating back, front, back, front, etc. Doesn't really work very well on the loose stuff. :lol3 There, it would be back, front, {faceplant}. :muutt

    My sis on the top of Mt. Evans:

    [​IMG]
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  7. raceu2

    raceu2 Adventurer

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    I had this problem in Mexico and it has persisted ever since. I have noticed that the rear master get hot from the exhaust
    with out using the brake. I think this may have something to do with it surly it doesn't help. Have 2 to one exhaust maybe generates more heat? Talked to a guy who had his pipes ceramic coated I know from my car this helps the pipe run cooler. Some kind of heat shield would be cheaper. I did flush the system when I got back..
    #7
  8. Yascher

    Yascher Been here awhile

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    Probably need to look into hetting rear brakes from the 1190? as it is bigger and will work more efficiently without overcooking itself
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  9. przjohn

    przjohn Been here awhile

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    Boiling the brakes is pretty common on Dirt bikes. The fix is a solid rear rotor, not sure if anyone makes one for the 990, Motul RBF 600 fluid, and the most important one, adjust the brake lever. The solid rear rotor helps disipate heat better, the fluid boils at a higher temp, and you need to stop riding the rear brake. You would be surprised at how much difference a little adjustment makes. You may not realize it but you can just be putting a little pressure on the pedal causing excess heat.
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  10. ciedema

    ciedema мотоциклист

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    Its not from unintentionally dragging the rear brake, rather doing so deliberately. :D I tend drag through loose stuff and washboard, when I ride hard on the pavement I also trail brake a lot. Its to the point that it is almost predictable. I find myself checking pedal pressure before going into a corner.
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  11. what car??

    what car?? down the road

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    Soo, that's the culprit when we were coming down a series of long steep hills in Guatemala. The misses didn't like it either, but it doesn't help when I'm cursing, f~k f~k sh!t damn out loud:rofl. I wasn't sure what that was I got accustomed to pumping the brakes before corners and when finally down and on the flats it went away. I knew the brake fluid could be changed so I thought that could be the culprit. Thus a brake fluid change once back in Xela. Good to know! Does the front ever do the same? I have a tendency to use the fronts when approaching corners on pavement. When I did bleed the system, filled, pumped, bled, filled, pumped, bled, repeat. I did this until the fluid was coming out clean.
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  12. Ozi

    Ozi Been here awhile

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    @cledema - FYI - I had a 1190 R for 2 years and regularly notice that my 1190 R rear brake fluid is in-effective after a long decent or other situation where i have been trail braking a lot ( i also own 2 x Ninjas and ride the same roads and never have this fade) - the KTM design seems unable to dissipate rear brake heat correctly, possible because of airflow issues around the exhaust air flow. In a recent group ride with more than 15 1190s present many riders including the instructor mentioned they regularly boil their KTM 1190 rear fluid and change it regularly. or bleed it regularly to remove bubbles from boiling fluid.

    I believe there are several possibilities with regard to the design inadequacy for these bigger 1190 rear brakes fitted to KTMS - riders please take a look at
    a) the colour of the fluid in your rear reservoir - is it black(boiled)?
    b) Take a look at your rear disc - is it blued? and finally
    c) take a good look at your rear KTM Brembo caliper is it perfect silver or does it show signs of heat damage that the anodising has browned off? - especially on the inside where the 3 tongues resist the slave opposite?

    The other issue is that the KTM 1190 rear brake return spring is too weak - i.e. when i removed the rear wheel and pads - i can pump the 1190 rear brake level with the tip of my little finger - ie the return spring is so weak that a rider would never notice he even has the brake applied when wearing decent protective gear - Sidi ADV boots.

    On the same day a sanctioned KTM instructor told me to raise my brake pedal - i subsequently had a major rear "heat" event on my 1190R rear brake that afternoon - without any notification from the ABS system that it was or had occurred or that the entire rear system was totally "failed/burnt" - no warning light - as its only really a hall effect sensor and itself oblivious of heat/hydraulic parameters ( this occured on a short 20km return trip on the sealed road) - i can only assume i had my foot resting on the raised pedal ( but could not feel it) and the entire rear caliper was destroyed with heat within a few km's without me even knowing (presumably people behind saw smoke and flames?) until the first attempt to apply rear brake the next morning

    I replaced the pads and temporarily used some metal-putty to rebuild the caliper to get me going - but the seals were burnt out in the slave.

    This event got me focused on the rear brake heat issue in 1190 KTMs and i now noticed on my wife's 1190 that her rear caliper is heat dis-coloured as well (from previous owner). She tells me she cannot tell if her foot is resting on or off the pedal it's so light a spring and often looks down to see.

    Edit - Have now fitted a stronger return spring to my 1190R rear brake to add more tactile "feel" to the pedal force (its a std Ninja spring) - doing some heat analysis with a thermal gun - On a short ride in 32°C where i deliberately did not apply any rear brake the rear disk/caliper is approx 30°C above ambient (65°C) compared to the front assembly which i did use aggressively and it remained cool ~rear disc heated just from being downstream of the engine/exhaust heat.
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  13. baloneyskin daddy

    baloneyskin daddy bikaholic

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    try the carbon brake pads.
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  14. Ozi

    Ozi Been here awhile

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    Did you have a personal benefit with carbon on your 1190?
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  15. DesertSurfer

    DesertSurfer Tail sprayin

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    I cavitated my rear brake on a steep decent during a hot afternoon. I was traveling down a ridge line with a sheer cliff as a shoulder. If I'd have had the extra weight of a passenger we both would have perished. My brake fluid was only 9 months old. Has anyone installed the Galfers rear wave rotor and report if it reduces brake overheating?
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  16. Ozi

    Ozi Been here awhile

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    @DesertSurfer so your fluid black boiled? Do you trail brake? was it a 950/990/1190? - different rotor idea is interesting option - my wife also has a RC390 with the KTM Wave rotor fitted on the front and its always running cool but so is her RC390 rear which never faded - then again on both our 1190 and 1190R the front are cool and never overheat even on the steepest roads ; hence reason to suspect exhaust heat-related on rear on larger KTM bikes we own - or if its TC related? - Springs, on her RC390 (with no TC) she also said she has difficulty knowing if she has the brake pressed or not pressed based on tactile feel, and has to often look down at her foot (apart from deceleration) - KTM rear brake springs seem to be extreme on the "lite" side
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  17. DesertSurfer

    DesertSurfer Tail sprayin

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    I believe as mentioned the proximity between single TI exhaust and rear brake master may have contributed, plus steep down hill rear braking over a long distance.

    I've since changed midpipe, went with cooler running carbon exhaust and just bought rear Galfer wave rotor to hopefully eliminate that scary issue.
    #17
  18. Ozi

    Ozi Been here awhile

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    Where did you source golfer wave disc from?

    I also have the factory bash plate (designed to heat air between the engine case and the thick solid boat shaped aluminum plates - kinda like heating elements between 2 metal surfaces with almost no airflow thru it) which "may" be generating super heated air and releasing it onto the right side rear brake system -in a IR gun test - got 30 degree increase reading from ambient on the rear caliper and rear disc just cruising around with no rear used for the rest run - fronts where ambient even with solid go stop , go stop, on same run (so when cooled the std brembo is work just fine up front) - I already have a wings carbon muffler - but my CAT is still fitted mid way in the rear of the KTM bash plate oven - so in my case heat iscoming from the KTM oven - bashPlate/headers/cat system - then spilling back to heat the rear brake system really well
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  19. Boatman

    Boatman Membership has it's privileges ;-)

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    I never had a rear brake problem on my 950 Adventure until I moved to western NC and started getting comfortable in the twisties. Once it happened it boiled every time I went out for a ride. Finally flushed the system and filled with DOT 5.1,,,,, haven't had a problem since.
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  20. DesertSurfer

    DesertSurfer Tail sprayin

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