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Discussion Starter #1
Hi everybody.

I am changing the brake fluid of my 2006 LT (ABS3 intergral system).
The wheel circuits are done.
Now,the control circuits.
There are 6 bleeders on the unit, some are difficult to reach.
The official procedure says to bleed each bleeder.
I am asking to myself::confused:
when making a fluid change whith no air in the circuit, do I actually need to bleed the 6 bleeders.
Do you think that bleeding only the 2 long ones could be enough.
(Illinois riders on their video bleed only two, but it is ABS2)

Thanks in advance for your advice

Bruno
 

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Do you think that bleeding only the 2 long ones could be enough.
Depends on whether or not you want to flush all chambers. I believe BMW is not flushing all chambers on standard flushes (so I have been told). Introducing air into the ABS 2 & 3 is very hard to get out (my experience anyhow).
 

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Hi everybody.

I am changing the brake fluid of my 2006 LT (ABS3 intergral system).
The wheel circuits are done.
Now,the control circuits.
There are 6 bleeders on the unit, some are difficult to reach.
The official procedure says to bleed each bleeder.
I am asking to myself::confused:
when making a fluid change whith no air in the circuit, do I actually need to bleed the 6 bleeders.
Do you think that bleeding only the 2 long ones could be enough.
(Illinois riders on their video bleed only two, but it is ABS2)

Thanks in advance for your advice

Bruno
Bonjour Bruno,
I hope you guys can still ride on your side of the Atlantic. Here in Montreal, the season is finished :-(

The procedure for CONTROL-Circuits is NOT that long considering that you only need to do it every 2 to 4 years (see below). That part of the whole bleed takes me about 1 hour. I am assuming you have the documentation for correct sequence to do these 6 ports (3 front and 3 rear)

In 2006, BMW came out with Service-Bulletin # 34 002 06 (019) that allows extended brake fluid renewal intervals for the “Integral ABS” system of many motorcycle models.
What was initially 2 years (for control-circuits) has been extended to 4 years. For a K1200LT with factory rubber hoses, they suggest to keep the "Wheel-circuit" interval every 1 year (no extension compare to initial specs)

In same Service-Bulletin, the “Control-circuits” has been simplified to the bleeding of only 2 “control circuit” ports on the unit (#3 and #6 in picture). In the past, the technician had to bleed 6 ports on the ABS unit. For those who do their own maintenance, note that the old (and longer) method must still be used when servicing any major component like the replacement of a brake line or the complete ABS unit.

MY PERSONAL OPINION on this:
a) because the "WHEEL circuit" reservoirs are partially vented (to outside air), the fluid will absorb more moisture, so they choose not to extend this one.

b) out of my 12 years ownership of the K1200RS, I have tried the new schedule and simplified 2 ports method only once. Next time I bleed the brake, the fluid was darker than usual, so I will stick to the old more conservative schedule and ALWAYS bleed all ports.

Obviously, you can do what you want it is your bike after all. By the way, a new ABS modulator cost is $US 2300 plus installation time ;-)
 

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Discussion Starter #4
Thank you for the answers


I think I will flush only through bleeders 3 and 6.
I will look at the color of the fluid. If it is not that dark I will leave the others bleeders alone.;)

Thanks again:wave

Bruno
 

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Thank you for the answers


I think I will flush only through bleeders 3 and 6.
I will look at the color of the fluid. If it is not that dark I will leave the others bleeders alone.;)

Thanks again:wave
Bruno
Bruno,
Maybe I was not 100% clear about my test (once) to bleed only 2 control ports (as suggested in Service-Bulletin). When I did ALL bleeders the next 4 years, it was much darker also for 2 bleeder ports that had been skipped the previous times. A few other members on the K1200RS forums had the same experience, so I am not alone with that conclusion.

So if you do bleed only 2 control bleed points this time, you have no idea (no base reference) how bad the fluid is in the other sections of the ABS modulator.

Of course the type of riding / braking and the storage conditions may be contributing factors in some cases. I believe my bike storage conditions (in winter) are very good and I am not that hard on brakes based on brake pads mileage I can achieve.
 

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I have been doing this for 10 years now and I only use the 2 ports for the control circuit flush. I found the amount of fluid in the cross passages to be less than 1/8 inch in my flush tubing. Not worth the effort. Maybe every second time (4 years) you could do all three but BMW did issue a service change to just use the two. By the way all the ABS units from 2001 up to 2009 are iABS with two configurations that are essentially the same internally.
 

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Discussion Starter #7
Since it is the first time I do it, I will take the easy way (2 bleeders).
Next time I will do the complete business (all bleeders).

Thanks again for the help.

Bruno
 
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