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Thread: Value of replacing most of the brake fluid in a 2004 RT?

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    Value of replacing most of the brake fluid in a 2004 RT?

    I like to use the local motorcycle shop for routine service work. They have done a routine motorcycle brake fluid change, which changes out most of the fluid in the front and rear brake lines. I did this before I realized you need to remove the gas tank to access all 3 circuits since it has power brakes. It is time consuming and expensive ( I would need to go to a dealer) for me to properly change the brake fluid.

    My question; how much value is there in a "routine motorcycle" brake fluid change as compared to changing out 100% of the fluid? I am not a mechanic, but I am assuming all 3 circuits have to communicate and by removing the fluid in both the front and rear reservoirs, front and rear brake lines and calipers, you are removing most of the old brake fluid?

    I am guessing people have been either intentionally or unintentionally doing this for years. And I realize it is not the ideal solution, but it is a compromise, and a lot better than not changing out the brake fluid at all.

    Thanks for any opinions.

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    . AntonLargiader's Avatar
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    Your shop doesn't know how these brakes work, and that is dangerous. They have not 'changed out most of the fluid' at all, and they have possibly left you with a system that might shut down.

    I assume that they changed the fluid in the external reservoirs and then bled a bit of fluid from the calipers. Those two circuits are totally separate. The fresh fluid in the external reservoirs will never go beyond those reservoirs, and the fluid that they bled from the caliper has not been replaced, meaning that the internal reservoirs are now low. You need to get this fixed by someone who knows the system (doesn't have to be a dealership, and it could be you if you are willing to learn about it and do the work).
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    Quote Originally Posted by AntonLargiader View Post
    Your shop doesn't know how these brakes work, and that is dangerous. They have not 'changed out most of the fluid' at all, and they have possibly left you with a system that might shut down.

    I assume that they changed the fluid in the external reservoirs and then bled a bit of fluid from the calipers. Those two circuits are totally separate. The fresh fluid in the external reservoirs will never go beyond those reservoirs, and the fluid that they bled from the caliper has not been replaced, meaning that the internal reservoirs are now low. You need to get this fixed by someone who knows the system (doesn't have to be a dealership, and it could be you if you are willing to learn about it and do the work).
    +1000. You now have a dangerous situation.

    the bleeding instructions are found here

    http://advwisdom.hogranch.com/Wisdom/service_abs3.pdf

    or on a CD that Jim sells. It is really fairly easy. I did a braided brake line upgrade and it was the easiest bleeding job I ever did. I really like the system and with the cost of the replacement, you really want clean fluid with good corrosion inhibitors in it.

    Rod

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    Quote Originally Posted by ragtoplvr View Post
    +1000. You now have a dangerous situation.

    the bleeding instructions are found here

    http://advwisdom.hogranch.com/Wisdom/service_abs3.pdf

    or on a CD that Jim sells. It is really fairly easy. I did a braided brake line upgrade and it was the easiest bleeding job I ever did. I really like the system and with the cost of the replacement, you really want clean fluid with good corrosion inhibitors in it.

    Rod
    Thanks for responding. I have viewed the instructions several years ago and decided this was a bit more than I was willing to get into. I will review them again. When I inadvertently had the incorrect procedure done, the brakes performed well, but maybe I just got lucky for 2 years. And I have since had the correct procedure performed. So the 3 circuits don't communicate with each other as was written earlier? And the majority of the brake fluid volume is in the center circuit?

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    Deleted my original reply - even with a disclaimer it might be a disaster.

    I could not believe the reply from AntonLargiader so I tried to find more information.

    I found a diagram:
    bmw_integral_abs_p0034934-b.jpg

    ...and changed my opinion.

    My opinion now is that's a really stupid design and if it were on my bike I would find a way to get rid of it.

    The circuits appear to be isolated hydraulically from each other.
    The circuits that actually do the braking use two separate reservoirs which are hidden under the tank.
    If you bleed fluid from the caliper you deplete that reservoir.
    Furthermore (I haven't read the procedure yet) it appears that in order to bleed the air out of the control side of the system, that has to be done under the tank as well.

    Frankly I wouldn't trust ANYONE to work on these for me unless I was standing there watching them.

    If you lose electrical power to the system the brakes should still work with manual pressure.
    However if you allow the power side of the system to get too low on fluid you'll have no brakes.
    Surely there is a sensor or something to warn you ??? of your impending death ???

    Hidden reservoirs? Requiring the tank be removed? With no visible level indication? Evil.
    Since manual pressure can be passed through - I would think you could re-plumb around the Evil directly to the calipers.

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    . AntonLargiader's Avatar
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    Quote Originally Posted by scott.lambert View Post
    I could not believe the reply from AntonLargiader so I tried to find more information
    ....
    Frankly I wouldn't trust ANYONE to work on these for me unless I was standing there watching them.
    Scott,

    I just have to wonder about this. If you knew nothing about the system before, how is it that you are going to supervise and check the work of someone who is professionally trained on it?

    This system has been around since the turn of this century. It's nothing new to trained mechanics.
    Anton Largiader 72724
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    Quote Originally Posted by AntonLargiader View Post
    Scott,

    I just have to wonder about this. If you knew nothing about the system before, how is it that you are going to supervise and check the work of someone who is professionally trained on it?

    This system has been around since the turn of this century. It's nothing new to trained mechanics.
    Welcome to the internet Anton, it's full of experts.
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    Ufda happens..........

    It's all about the details.

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    MOA #24991 Pauls1150's Avatar
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    Ex and spurts... yeah....

    Thomsen, allow me to add from personal experience: It is easy to get an air bubble trapped somewhere and not show itself for a day or two or three... Then you're up on the freeway and you grab some brake, and the lever comes back to the bars...

    While the procedure can indeed be successfully carried out by anybody who understands what they're doing, unless you have the BMW Computer to verify the hydraulic pressures in the system, you're still taking a chance.

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    Air bubbles are compressible. They always show themselves as increased travel. I just replaced all my lines. Basically I started with a MOAB. Mother of all air bubbles. I could easily feel the air, and when I was finished I reduced the travel on the front brake lever. It was the easiest bleed job ever, thanks to the pump in the ABS. I did buy the ministan from beemer boneyard, it was worth it to me. I do not know what you did, but an air bubble in the lines is easy to feel. It is a good system, and really easy to bleed, if your fuel lines and quick disconnects have not been changed the tank needs to come off anyway. There is a abrupt behavior at low speeds issue, takes a lot of getting used to, other than that it is a good system, no need to take it off until it fails.

    I think I would get mine fixed or replaced.

    Rod

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    Quote Originally Posted by AntonLargiader View Post
    Scott,

    I just have to wonder about this. If you knew nothing about the system before, how is it that you are going to supervise and check the work of someone who is professionally trained on it?

    This system has been around since the turn of this century. It's nothing new to trained mechanics.
    I'll have you know I have been full of crap for much longer than that. Since at least 1982.

    I think what I meant to say was that the system is intrinsically dangerous and that knowing what little I have learned about it in the past 20 hours, I would not trust anyone but myself to work on my servo brakes. I would learn all there is to know about it and I would work on it myself.
    I know that's not fair and not reasonable for normal people.

    The OP took his ride to a "local motorcycle shop" - maybe not trained on BMWs.

    The design really bothers me. If you remove fluid from the powered side, fluid leaves the visible reservoirs on the control side.
    Without specialized training, even if you traced the lines under the tank, you'd be within your rights to assume that this fluid came from that circuit.
    There's nothing under there that looks like a reservoir.
    How many of these are out there getting the "routine" service from shops like this?

    I'm not all up in arms about it, I have an 1100 with the Brembo system and I like it just fine.
    It will loft the back tire if I mash on it - I think you can't really stop harder than that without retro rockets.
    I feel like the servo system is an answer looking for a question. A horribly complex answer.

    Godspeed with your whizzy brakes. I'll have none of it.

  11. #11
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    This brake system has been around a very long time.

    If you are old enough to remember, ABS was introduced back in the 60's. Didn't work great then but its still the same basic principals in 2013. Dual servo brakes have been around since WWII in FWD trucks, didn't work so great back then and integral braking, think back to the day when you blew a brake line on Gramp's truck and you went for a bit of "ride". There was even a time, 150,000 lbs of semi hurtled down the highway without front brakes. Then they got real smart and put front brake limiting on them. Imagine, front wheels locked and the drives and trailer have twice the brake pressure. Can you say, "Yee Haw, OH DAMN!" Shortly after that, you had a couple scenarios, a crash, needed new underwear or you and everyone in your path was just dead.

    The point I'm trying to make, and I keep trying to make on these forums, there a fart smellers or smart fellers out there. There is no way I'm smart enough to know everything but I am smart to know I don't know everything and I enjoy reading the "opinions" expressed here. There is more than one way to do a given task and certainly different ways to understand the same basic principals.

    After reading this post, I'm glad I have an R1100RT instead of the more complicated systems. I think that's mostly because I'm lazy and just want to ride.

    Last couple comments, BMW hasn't used an original system, ever. They are proud of introducing CAN BUS Multiplexing on the cars/bikes as "innovative". Your first Window's printer is more complex and It's been around since 1990 on machinery. Every technician/mechanic deserves respect. They ain't turning wrenches for a living because they are stooopid. Factory/dealership training aside, we are just like everybody else, dirtier at times though.

    Read, listen, learn and the power comes to your hands. If you believe everything on the internet, you will also believe that polar bears swim with penguins.
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    Registered User mpmarty's Avatar
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    Simply put the choice is yours:

    Either take it to an authorized BMW dealer and pay to have the job done properly or, wait until the unflushed circuit fails and pay $2500 or more for a repair that you could have avoided.

    I had an 04 RT and did my own flush following the directions posted earlier. I now have an 06 RT with the same or very similar system and every two years I do the flush service with nice new Dot 4.
    Marty - in the western Oregon mountains.'06RT, (gone '04RT, '86 Venture Royal, '81 Yamaha Virago920, '82Suzuki GS1100GK, '76 Suzuki GT750, Triumph 750 Bonneville, BSA Road Rocket 650, 61" Harley knucklehead)

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    Thanks to everyone who took the time to respond. There are a variety of opinions, but it is clear that you can't do an effective job without pulling the tank and getting to all the brake circuits. Thanks again.

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    Jammess jammess's Avatar
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    Quote Originally Posted by Thomsen View Post
    I like to use the local motorcycle shop for routine service work. They have done a routine motorcycle brake fluid change, which changes out most of the fluid in the front and rear brake lines. I did this before I realized you need to remove the gas tank to access all 3 circuits since it has power brakes. It is time consuming and expensive ( I would need to go to a dealer) for me to properly change the brake fluid.

    My question; how much value is there in a "routine motorcycle" brake fluid change as compared to changing out 100% of the fluid? I am not a mechanic, but I am assuming all 3 circuits have to communicate and by removing the fluid in both the front and rear reservoirs, front and rear brake lines and calipers, you are removing most of the old brake fluid?

    I am guessing people have been either intentionally or unintentionally doing this for years. And I realize it is not the ideal solution, but it is a compromise, and a lot better than not changing out the brake fluid at all.

    Thanks for any opinions.
    You know it sounds like maybe your shop is treating your 1150 like an older and simpler 1100 with ABS. On my '94 R1100RSL it is not necessary to remove the tank and directly bleed the ABS modulator just bleed and flush the brakes by using only the front and rear wheel bleeders. Needless to say I like the ABS on my '94 much more than the system that WAS on my '04 1150RT. Notice that I use the word "was" as a couple years ago the entire ABS system somehow just disappeared from my '04. Odds are I will regret having removed the ABS system from the '04 when I attempt to sell the big top heavy beast.
    Jammess

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