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Discussion Starter · #1 ·
Tickets popped a front brake line last weekend so I bought her a whole set of new Speiglers. I installed them on Saturday, but I have air in the system that I can't seem to fix. Here are the symptoms:
1. No power to the ABS - rear brake works fine and stops 1/2 way through travel against the calipers. Front brake can be fully retracted and will not stop against the calipers.
2. Power to the ABS - rear brakes appear to be completely normal. Front brake is 1/2 second slow to engage the calipers as the ABS unit builds up the pressure....and if I grab the brake hard, I feel a kickback from the ABS as it builds back pressure into the system.

I've tried to clear the ABS with multiple passes of the different circuits in the order of port 1, 2, 3, 1.

One thing to note, I've found pictures of the ABS unit in previous posts, but mine is different from the pictures that I've found. My port 2 is not between the port 3 pegs. It is on the top right side of the ABS unit with the battery blocking access to it, so I've removed the battery until I can get the calipers to actuate without the ABS.

Have any of you run into this before and recovered without going to the dealership for service? I have not tried back filling through the ports, I've only been filling the handlebar reservoir and squeezing brake fluid out through the ABS.
Any helpful suggestions will be appreciated. I really don't want to bring her to BMW. Thus far, she's never been to the doctor because you guys have always helped me nurse her back to health. I'm afraid that I might need some expensive specialized equipment to recover this time....
 

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Wrencher Extraordinaire
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The 1,2,3,and 1 again is only for the control input side. You need to fill the reservoirs and bleed the air out at the calipers as well. You can let the ABS pump do the work here just keep the reservoirs full. Here is the ports on your ABS.

On the reservoir the rear half is for the front wheel circuit while the front half is shared between the rear control and rear wheel circuit.
 

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Like John said . . . (of course!). To keep the reservoirs full as you pump the ABS servos a neat trick I learned here is to replace the two reservoir cap overflow tubes with tubes dipped into a can of clean brake fluid. Start with reservoirs full and caps replaced and as you pump, fresh fluid is sucked in to keep the reservoirs full.
 
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Discussion Starter · #4 ·
Thanks guys, I will give this another try and let you know how I make out.
 

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+1 for doing it at the calibers
 

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Discussion Starter · #6 ·
Thank you all for your wonderful recommendations. I figured out what I was doing wrong. It's only slightly embarrassing so I thought I would share it, so others can avoid the same.

I had done the calipers prior to my posting, but I was concentrating on the ABS bleed because I had read that it is difficult to get the air out of the ABS unit once it is in there. I use a 5 foot long piece of 3/16" tubing to run from the front calipers to the rear reservoir when I bleed the front brakes. I attach the hose to the caliper and then run it up to the reservoir and hold it with a zip tie near the reservoir. Before I turn things on and run the ABS, I fill the tubing with brake fluid so that I don't need to worry about draining the reservoir. That's my setup.

The first attempt at bleeding the calipers went like this: I loosened the bleed screen and ran the ABS. Many bubbles came out and eventually they became smaller and I remember that the bubbles stopped moving and settled at the top of a bend in the tubing. I didn't think much of it while I continued to run the ABS and concentrated on the amount of air coming out of the caliper. When the bubbles stopped coming out, I thought I had flushed out all the air and I tightened up the bleed screw.

So this time, I did the same thing and, of course, more bubbles came out of the caliper. I continued to run the ABS until the bubbles stopped coming out and then I closed up the bleed screw. As I was removing the tubing, I noticed that the same bubble was present in the high portion of the tubing that was there the first time. Again, it just didn't click in my mind....

But, while I had everything hooked up. I thought that I should run it a third time to be sure. I loosened up the bleed screw and ran the ABS. More bubbles came out and I noticed that the big bubble in the loop had been pushed into the reservoir. That's when it dawned on me that I had a flow problem.

What I determined is that the pressure from the ABS is such that it is powerful enough to turn the bleed screw slightly and close the flow (or it shakes the tubing enough that the tubing tries to return to its original orientation by turning the screw closed)....so when you think you're done because no more bubbles are coming out, in reality there may be nothing coming out because the screw rotated shut.

I ran it again and watched as all the bubbles were pushed all the way through the tubing to the reservoir and then some. Closed the bleed screw and tested the brakes. All is good again. Thank you for the help.
 

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Thank you all for your wonderful recommendations. I figured out what I was doing wrong. It's only slightly embarrassing so I thought I would share it, so others can avoid the same.

I had done the calipers prior to my posting, but I was concentrating on the ABS bleed because I had read that it is difficult to get the air out of the ABS unit once it is in there. I use a 5 foot long piece of 3/16" tubing to run from the front calipers to the rear reservoir when I bleed the front brakes. I attach the hose to the caliper and then run it up to the reservoir and hold it with a zip tie near the reservoir. Before I turn things on and run the ABS, I fill the tubing with brake fluid so that I don't need to worry about draining the reservoir. That's my setup.

The first attempt at bleeding the calipers went like this: I loosened the bleed screen and ran the ABS. Many bubbles came out and eventually they became smaller and I remember that the bubbles stopped moving and settled at the top of a bend in the tubing. I didn't think much of it while I continued to run the ABS and concentrated on the amount of air coming out of the caliper. When the bubbles stopped coming out, I thought I had flushed out all the air and I tightened up the bleed screw.

So this time, I did the same thing and, of course, more bubbles came out of the caliper. I continued to run the ABS until the bubbles stopped coming out and then I closed up the bleed screw. As I was removing the tubing, I noticed that the same bubble was present in the high portion of the tubing that was there the first time. Again, it just didn't click in my mind....

But, while I had everything hooked up. I thought that I should run it a third time to be sure. I loosened up the bleed screw and ran the ABS. More bubbles came out and I noticed that the big bubble in the loop had been pushed into the reservoir. That's when it dawned on me that I had a flow problem.

What I determined is that the pressure from the ABS is such that it is powerful enough to turn the bleed screw slightly and close the flow (or it shakes the tubing enough that the tubing tries to return to its original orientation by turning the screw closed)....so when you think you're done because no more bubbles are coming out, in reality there may be nothing coming out because the screw rotated shut.

I ran it again and watched as all the bubbles were pushed all the way through the tubing to the reservoir and then some. Closed the bleed screw and tested the brakes. All is good again. Thank you for the help.

Nothing like the thrill of victory. :smile:
 

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2002 K1200LT; Rear brake line busted; ordered spieglers; supposed to be here by this weekend so plan on replacing the lines on Saturday; the brake bleeding /ABS has me a bit uneasy; am 32 miles/$300.00 and two-three weeks if I take it to BMW; thus far I have changed air/oil/fuel filters; oil/transmission/rear drive fluid changed; had the wig wags so topped off the brake fluid; went for test drive (just purchased the bike and had not ridden it yet again); pressed rear brake and fluid everywhere; can see where the brake line has tear in it;

Have read and read and watched the Illinois bike club videos to get me this far; Illionis bike club prez shows how to change the lines but separate video on bleeding; but don't think that one applies if changing lines due to air;

Any pointing me in the right direction would be appreciated..
Ron
 

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Discussion Starter · #9 ·
2002 K1200LT; Rear brake line busted; ordered spieglers;

Have read and read and watched the Illinois bike club videos to get me this far; Illionis bike club prez shows how to change the lines but separate video on bleeding; but don't think that one applies if changing lines due to air;

Any pointing me in the right direction would be appreciated..
Ron
Well, how did it go? As mentioned, I use a long clear tube to circulate the brake fluid during the bleed. Otherwise, I find that it's more of a two person job. Replacing the brake lines is very easy, clearing the air from the system is only 'minor difficulty' with the right setup/tools.
 

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I had been a bit scared of bleeding / flushing the brake system (Integral ABS) but now that I have had a calliper seize and given the amount the dealer was going to charge me I had to have a go at doing it myself. Figuring I had nothing to lose but some brake fluid.
The previous poster mentioned a tube from calliper to reservoir and that is exactly what I did, just top up the reservoir using a small syringe and then run the system until no more bubbles come out.
Hope the pictures make it clear.
It was so easy I am afraid I have missed something, surely it is meant to be harder than this !
 

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Works just fine didn't it. Looks like you did everything right. That only works on the wheel circuits. Control circuits a just a little bit harder.
 

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Discussion Starter · #12 ·
That looks like my setup. Just watch out that the tube doesn't untwist and cause the bleed screw to close, thereby making you think that you've bled out all the air. I should have taken pictures to post, but digging out my camera while my hands were dirty and getting DOT 3-4 on it was not an option at the time. The forum will appreciate the pictures. Great job!
 
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