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Discussion Starter · #1 ·
The current problem is that the "Brake Failure" and "Hazard" (Wig Wag lights) are flashing very fast (about 10 times per second) - this is not just a low brake fluid warning. I have a 2003 K1200LT.

I'm planning to take the bike to my regular BMW mechanic (Chris is not a BMW dealer but specialises in BMW bikes) who has a computer that can read the error code. However I'm not sure if it was Chris who might have been responsible for the sticky rear wheel brake I experienced last time. So I thought getting some feedback from this forum before going to Chris might give us some ideas on how to proceed.

Let me provide a bit of background information...

Last year, I got my rear brakes changed by Chris (non BMW dealer but specialises in servicing/ fixing BMW bikes), but then I started to experience 'sticky' rear wheel brakes. This means when I used my foot brake, the rear brakes would grip the rear disk but when I released my foot brake pedal, the rear brakes would not release the rear disc brake completely. (I posted my last problem about a sticky rear wheel brake - http://www.bmwlt.com/forums/showthread.php?p=682634#post682634).

I told Chris about the suggestions from this forum was to clean the brake calipers and he said he used the regular BMW brake piston tool to push/ reset the rear brake pistons. He said he was booked up till Jan 2014 and he was not keen on working on the LT because it's too heavy for him (he's in his 60s). So I went to another mechanic (Mike who was recommended by the group I ride with but is not a BMW specialist and does not have a computer that can read the BMW error codes but can hire on but will pass the costs to me). He looked at the issue and immediately said it was caused by dirt/ grit getting into the brake calipers.

Mike cleaned the brake calipers and brakes were not sticky any more and the rear wheel free-wheeled easily. When riding back from Mike's workshop (late Nov 2013), the wig wag lights (flashing alternating between the "brake failure" and "hazard" lights at about 1 or 2 per second) appeared about 15 minutes into the ride. I thought it was just low brake fluid and I thought nothing of it, although the foot brake did feel soft (I needed to press harder to get the same braking force).

However while riding to work the next morning (after picking the bike up from Mike who had just cleaned the brake calipers) the wig wag lights rate of flashing went from 1 or 2 per second to about 10 per second (I had never seen this before). The foot brake felt soft still and then as I was riding, I experienced total brake failure (which scared the heck outta me).

I got to work safely (thank God) turned off the bike with the key, called Mike and arranged to have the LT towed to his workshop. I noticed when moving the bike for the tow truck that when I re-started the engine (after having turned off everything while waiting for the tow truck) that all the brake warning lights had gone off and the brakes seemed to work again - which got me thinking it might be an electric/ brake pump issue.

Mike checked for brake fluid around the nipples but didn't find any brake fluid. He topped up the brake fluid to both front and rear brake fluid reserviors and all the warning/ wig wag lights went off.

I picked up the bike in late Nov and all was well. I did a ride up the mountains near Brisbane Australia in early December 2013 (the day before I went on a month long holiday) and all was well.

However when I got back from holidays two days ago (early Jan 2014), and the wig wag lights (alternating flashing at 1 -2 per second) came back on as I was riding to work. I just thought it was a case of slightly lower brake fluid. However as I was riding, the flashing rate increased to 10 per second. This made me worried that I might experience brake failure again, so when I stopped at a stop light, turnned off the engine and battery (using my key) and turned it all on again. The slow (1-2 per second) wig wag lights came on but the brakes still felt normal (brakes engaged with the level of force I was expecting/ used to).

Then after riding for a while, I saw a new warning light sequence I have never seen before - the "brake failure" light was flashing at between 2-3 times per second BUT the hazard light stayed lit the whole time. After some riding (about 5 mins), the warning light sequence went back to the rapid wig wag (10 per second) and again the brakes started to feel 'soft' (ie not stopping me as quickly/ forcefully as I'm used to). So at the next stop lights, I used the key to turn off the engine and electrics and fired up the bike again. When applied the brakes seemed to 'bite' like they're supposed to. I managed to get to work safely (the rapid wig wag was happening again but brakes performed like normal) and I powered down the bike.

Riding home, I noticed the same 'new' warning light sequence of the "brake failure" light flashing but the "hazard" warning light staying on constantly. Again after about 5 mins of the 'new' warning light sequence, it went to the rapid wig wag.

Thank God I got home safely.

Does anyone have any idea what's going on? Is this a brake pump issue, a problem with my brake lines or am I having issues with my brake fluid reserviors (although there aren't any brake fluid patches on the floor at home or work)?

I called up the BMW dealership in Brisbane and talked through the issue. He said that he'd need to check the computer/ diagnostics (and their labour rate of $127/ hr and about 2+ hours, I could be up for about $250-$300 just to work out what's wrong. If it ends up being a faulty ABS unit this could end up costing me about $4000 ($3400 for a new ABS unit and $600 for labour).

Please help. What should I do/ what would you do? Has anyone had a similar experience?
 

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Wrencher Extraordinaire
2005 K1200LT
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Sounds like your ABS unit is on the way out mate. The slow wig wag is fluid levels and the only reservoir that is monitored on your bike is the 2 chambered unit under the pillion seat near the front of the side bag. Some times a weak battery can cause weird failure modes as these units do draw a large amount of current. But I don't suspect that in your case. There may be a mate near you with a GS-911 and it can read the failure codes. But again I do suspect the unit is having a failure internal.

See post #74 here not sure how far away he is from you.
 

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Hi Joseph... afarid I can't help you with brake light warnings info, but I'd trust JZ's observations...
One comment from your pic (knowing how scary it is to get an LT onto the back of a towie, especially when its raining & slippery!) is that the handlebars aren't good tie down points, can cause damage... they should always use the front forks. There's tie-down instructions on the site somewhere (here).

John, the other GS911 owner (alfred02) is probably at least 300 km's away to the south.
 

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Wrencher Extraordinaire
2005 K1200LT
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One other item is flushing the fluid regularly. I did not see mention of that. While I don't want to get your hopes up a flush with fresh fluid could not hurt anything but your wallet at this point and may be money well spent. It has fixed issues on a few occasions but is not a fix all. The requirement is wheel circuits every year and control circuits every two years.
 

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Discussion Starter · #5 ·
Thanks so much for your replies and ideas. After reading another thread, I think I might have omited what could potentially be another important piece to the puzzle.

Well, after owning my LT for about 6 years and proud that I never dropped her, it finally happened. My wife and I went over to the cabela's store in Owattona MN. Waiting for a car to leave a parking spot, I 0was virtually stopped, having the handle bar a little far to the left - I new she was going down. I slowly laid it down on the left side. Another couple who just parked their Goldwing ran over to help pick it up. No damage except abs lights flashing. Plugged the GS911 in when I got home and reset them.
After reading this I was unpleasantly reminded that when I went for my ride in the mountains (on the day prior to leaving for my month-long holiday). I had stopped and gotten off my bike to take a photograph. However because of the gradient of the slope, the wind and *stupid me* for leaving the bike in neutral and not putting it in 1st gear, it moved forward off the side stand and went down.

No major damage because it landed on the wings. But I'm wondering if this could somehow be related because I think it was after that point that the slow wig wag started and I just thought some brake fluid had come out somehow.

So after reading the other post, perhaps all that needs to happen is reseting the computer.

On a slightly unrelated note - The guy how helped me get it back upright happened to be a BMW rider and he noticed some final drive oil where the final drive seal is. I've never had any final drive leaks before, even when I've had to lie the bike down in the past, but that said, the three previous instances were all flat ground (and which never triggered the brake warning lights) and this instance it was a slight inclinde, so I just thought it was the incline (front lower than back) that caused the final drive fluid to seep out. I've been checking since and there hasn't been any more final drive oil loss (or brake fluid loss for that matter).

Do I have anything to worry about with the final drive?

Sounds like the next step is to hook the bike up to the GS911 computer and see what the machine says and reset the warning lights if they were triggered by the bike going down on its side.
 

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One other item is flushing the fluid regularly. I did not see mention of that. While I don't want to get your hopes up a flush with fresh fluid could not hurt anything but your wallet at this point and may be money well spent. It has fixed issues on a few occasions but is not a fix all. The requirement is wheel circuits every year and control circuits every two years.
OK, this is a silly idea, but in addition to what John suggested.

Following a complete SS brake line install, on my 00 LT the wig-wag kept coming on while riding. The machine had sat for some time because of maintenance projects, etc.

The GS911 showed a piston failure on the ABS unit (this is the older unit, remember 00 LT). The fluid levels were good and NO air in the system (I bleed it multiple times). Out of desperation, I took the machine out on a "hard pack" road, and purposely caused the ABS to work multiple times (remember this is a desperate and possible dangerous move on an LT). I'm sure some of the experts will debunk this but, forcing the pistons and pumps to work may have forced a piece of trash out of my system. Don't know if it is fixed as yet and still may be facing a pump replacement/rebuild, BUT have well over 2,000 miles since the work and no wig-wag as yet.

Just something to think about. :bmw:
 

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Wrencher Extraordinaire
2005 K1200LT
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Sounds like the next step is to hook the bike up to the GS911 computer and see what the machine says and reset the warning lights if they were triggered by the bike going down on its side.
The 2003 has a different ABS unit and it will self reset when what ever was causing the fault has been corrected. The GS-911 will tell you what any of the stored and current fault codes are though, but until they are corrected you will not get a reset.

Oil at the seal alone on the final drive is not a good indication of an impending failure unless the rear wheel wobbles real bad. When a bearing failure causes a leak it almost not ride able (There will be no doubt...). Seal replacement may be in order, but first clean it really well as the oil could have come from the breather on top of the drive. Then keep an eye on it.
 

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Discussion Starter · #8 ·
I think I might have gotten to the bottom of this mystery.

I found out that my fast wig-wag was due to this fault code -
17419 Rear ABS motor defective.

There was another code that had since been cleared
17162 Internal control module error - front pressure too high (>5.5 bar)

I spoke with someone who worked at BMW in Germany (who now lives in Brisbane and will be working on my bike from now on) and he said the first generation of these ABS brakes have seals in the ABS units and potentially what might have happened is when the brake callipers were worked on (to be cleaned - by ****), the pressure in the line was not released first and this cause the ABS seals to be compromised which then caused the brake failure (and the brakes felt soft because there was no pressure in the brake lines).

When the mechanic bled the brakes to solve the brake failure problem (after the bike was towed to his workshop), this put pressure on the seals and sucked or pushed them back into place. However some fluid got into the ABS unit and damaged the electronics connected to the rear pump.

The only thing that's still a bit unclear to me is that **** is saying that when the engine is off, the brake lines equalise to atmospheric pressure and thus could not have blown the ABS seals (because the brake fluid is not connected to the ABS seals). Is this true? **** said when he were working on the brake callipers (he said he followed the manual and all he did was expose the pistons, clean the pistons and reset the calliper pistons - and there was no need to release pressure in the brake lines because it equalised to atmospheric pressure).

Can anyone validate if pushing the pistons back can to blow the seals in the ABS unit (especially if the brake pads have worn down a lot)?

If this is true, the implications are huge for anyone working on their brakes to release pressure in the ABS unit / brake lines when working on your brakes/ brake pistons/ callipers so you don't blow the seals in your ABS unit and eventually destroy your ABS unit - which will cost me A$5200+ (about US$5000) to fix (labour included).

This version of events could possibly explain the sticky brake issue I was facing (http://www.bmwlt.com/forums/showthread.php?t=76338) when the first mechanic (Chris) changed my rear brake pads and used the BMW brake piston tool to push the pistons back. If the pressure was too high, this was causing the brake pistons to push back against the brakes which is why they brakes were semi engaged.

It'll be good to get to the bottom of this.

The alternative to getting a new ABS unit and installing it appears to be capping off the ABS so that I do not have any more ABS or servo assist.

I'm happy to hear anyone's thoughts about that too.
 

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I'm not sure about the later '01s to '04s, but '05s and newer have a vent tube attached to the tops of the ABS reservoirs. Pushing the caliper pistons back will push the fluid back, but if there's too much, it'll run out the vent tubing. If there weren't any vents, pushing the pistons back would increase pressure. I've no idea if it would be enough to cause internal seal damage.
 

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Lee my 03 has a vent tube on also I think you are right I do not think you could build any pressure up to hurt your ABS unit.I have had it come out of that tube if I filled it way up it would work a little out it until it got down where it was suppose to
 

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2005 K1200LT
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Pushing the pistons back to eliminate fluid in the calipers for a flush is specified in the BMW manual. This will not compromise any "seals" in the ABS unit. There is no "pressure" in the lines except when applying the brakes and if this was not released then the brakes would not release. Common issues with the 17419 fault is just the motor itself and usually brushes. Occasionally the pump can corrode if not flushed regularly and stall the motor. There is a body seal on the electronics housing on the ABS. Here are a few shots of a unit apart.
 

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