I have a 2003 K1200LT and I'm starting to experience the Brake Failure light and the Hazard warning light flash and alternate left and right (these two are side-by-side). I've found that turning off the ignition (turning the key and not just killing the engine) and restarting usually stops this, although of late, they come back on again and doing this one or two more times makes the Brake Failure and Hazard warning lights stop.

My mechanic told me that if there really was a problem with the brakes, they would not reset until the brake issue was addressed. That said I've got it booked in for a check (although he's backed up till Dec 2012 - 3 months away).

I first noticed this problem when I got a drip charger for the battery and usually after a charge, this brake failure warning light issue surfaces and then after a few days, it tends to subside. So this makes me think that the issue might be electrical/ electronics related.

The bike still brakes the same regardless of whether the brake failure and hazard warning lights are 'doing their dance'. The brakes are noisy but it's always been this way.

I'm looking to do a 1000km (3 day 2 night) ride in about 2 weeks and was wondering if I should call it off until I can get the bike looked at or just keep turning the engine off and on again until the brake failure light dance stops (which it always does... eventually) and the bike rides and feels normal.

I appreciate any advice, especially from people who've had a similar experience.

Cheers,
Joseph (Brisbane, Australia)

I just had this and if you search for wig-wag on the forum you will see a wealth of info.

FYI - Mine went away after refilling both rear reservoirs with brake fluid. Pad wear drops the fluid level and sensor is touchy it seems. Check the front too.

Hope this helps

Usually the "wig wag" flashing indicates a low fluid level in the rear , two chambered, reservoir. It can also come from a weak battery. If you get the lights after several hard stops then the battery is weak. But try adding a little DOT 4 fluid to both the chambers on the rear reservoir anyway.

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Thanks all for your valuable contributions. I think it's a battery issue because I have to reverse out of my driveway in the mornings and all morning on the way to work, the lights come on and do the wig-wag dance. However afterwork, on the ride home, the wig-wag hardly happens.

I'll top up the brake fluid anyway. I'm seeing Dot 4 and Super Dot 4 (which is only $2 more expensive for 500ml). Is it worth spending the extra, considering I'm already putting premium 98 octane fuel in the bike?

I'm starting to think my wig-wag (brake failure/ hazard warning light dance) might be due to the drip charge battery charger that I put the bike on.

I put the drip charge battery charger on last night when I got home from work (selected motorcycle mode not car) and this morning the charger showed that the battery was full.

After I reversed the LT out of the driveway (maybe 5m) the wig-wag dance began. I turned of the engine using the key and restarted and wig-wag stopped for a few minutes and then it started again..

Then it dawned on me that maybe the drip charger in motorcycle mode is made for smaller batteries (for smaller, non LT motorcycles) and might somehow be reducing the excessive charge of my battery - considering that I first noticed the wig-wag dance after putting the battery on the drip charger about two years ago, but it only came on initially after a charge and then stopped after about one day and usually after one key off/ engine off and restart. Now the wig-wag happens everyday.

Anyone have any thoughts.

Also I'm going to put some Dot 4 brake fluid (does anyone think it needs to be Super Dot 4 - $2 more expensive for 500ml from $10 to $12).

Finally, not being too mechanically minded, lifted the rider's seat but can't find the brake fluid reserviour similar to an earlier picture.

So I've taken a picture. Is the brake fluid reservior the single white bottle with the long neck (on the left if seated on the bike)?

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You don't need Super DOT 4, regular DOT 4 is fine. The difference is in the boiling point. Super DOT 4 was/is intended for racing applications. Filling the reservoirs as John Zeiler suggested will probably cure your wig-wag problem. I had exactly the same issue with my RS. In the mornings when cold or with the motorcycle facing downhill the light show would begin. After work when it is warmer and the bike is level the lights would stay off. The brake fluid level was at the critical point where temperature gradients and slight bike movement would cause the sensors to detect low level. Filling the reservoirs cured the problem.

The white bottle on the left with the long neck and the black cap is your coolant reservoir. The brake reservoir is on the right side of the bike. It has two black screw caps. You need to remove the passenger seat too. Read this thread:

http://www.bmwlt.com/forums/showthre...69517#poststop

for my 03 it was a sign the rear brake level was low. It would always go on at the bottom of the hill in cool mornings. Then restart on level it would go out for the rest of the commute. I've heard a low battery can trip it too but it never happened to me.

Dot 3 or 4 would do, so I would say no need for extra-super-duper fluid really for a street application.

The reservoir in your pictures is actually for the engine coolant. The brake reservoirs are on the right side of the bike.

Guys,
I have the same problem with the Wig-Wag thing. I checked my rear brake fluid reservoir and it was at minimum. I filled it up to max and I thought I was good. Unfortunately, on cooler mornings, I still get the wig-wag thing until the bike runs for a short time. I turn off the ignition and turn it back on and the wig-wag goes away and doesn't come back until the next morning. When I leave work in the afternoon (and it's warmer out) I start the bike and I don't experience the wig-wag lights.
Next cool morning, I repeat the same sequence.
You reference both chambers in the reservoir. Where is that? Here is a pic of the reservoir filler cap for my reservoir. I don't see anything on my bike like you are showing on your pictures.
See my attached picture.

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I had the same problem. Check your rear brake fluid. Its location under the seat. Mine was completelly emphty. Added fluid and all is well.

Thanks, but I did that already. My problem is that J's picture shows a two tank reservoir. On my 2005 LT I only see one fill cup, that I added Dot 4 fluid to. Does you rear brake fluid tank have one or two tanks.
Look at the pic I posted. (that is the cap for the reservoir under the back seat on the right hand side). Then look at J's pic.
Thanks

I had the same problem on cool mornings when the bike was new. I called the dealer and they said rear fluid was probably right on the edge. When it was cold it contracted just enough to set off the sensor. I kept checking and the reservoir looked full. When I went into the dealer they showed me there are two reservoirs back there. The back one that is almost impossible to see was low. They filled it up and Ive never had a problem since.

Bruce

You are in the wrong area for an 05 and up. The monitored reservoirs are ON the ABS unit. These are usually not that sensitive to low fluid so I would check your brake pads for wear first then add fluid to the reservoir. The tall one (inboard) is for the front circuit and the short (outboard) one is for the rear.

In the second photo a funnel is shown in the rear reservoir.

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So this looks like the left side of the bike right behind the knee cups.
So what is the reservoir that I pictured on the right side?
The lettering on the cap does say to use Dot 4 brake fluid. It has a min and max line on the fluid cup.
Thanks.

OK Here is a little I-ABS 101. There are four separate circuits a front control, rear control, front wheel and rear wheel. The fluid does not pass from control circuit to wheel circuit. In other words the little round reservoir holds the rear control circuit fluid that presses from the pedal to the ABS unit. Then the ABS unit senses that pressure and runs a pump to drive fluid out to the caliper. Like wise for the front. There is some linking between the control circuits that engage both wheel circuits under hard pressure even if you only apply lever or only pedal. Thus the "linked" brake system.

The level is hard to see on the wheel circuit reservoirs as they are black ABS plastic so if you add fluid do so slowly and I recommend a small syring and tubing to do so. Fluid should be at the top of the "white" ring (actually a sleeve filter) you see when you open the cap with an 8 mm allen.

This level should only be set with the caliper pistons pushed fully in. And as I stated before ususally if you get the wig wag on an 05+ it means your pads are about worn out.

Hi again,

Thanks all for your valuable input.

I finally tried to put the Dot 4 brake fluid in.

I took the rear seat off (well I couldn't quite get it off because the wire that heats the rear seat was connected. I tried trying to release the clear/ white plastic clip but it just wouldn't budge... but anyway, I managed to get the seat out of the way while still connected to the heating wire).

The first photo show that the brake fluid reservior is on the right and right under the frame and next to the tupperware.

I could only access the higher cap (which I'm guessing is for the rear reservior). I had some trouble accessing it and releasing the cap, so I started to try and removed the tupperware. I had to use a five point/star screw head (why doesn't BWM just use regular philips head screws???) and I managed to remove three screws on the tupperware, but then the tupperware still didn't come off. I needed to remove more screws near where the brake peddal is but that needs a large allan key (different from the one needed to remove the rear seat - why doesn't BMW just use a few standard sizes???).

So I resigned myself to being limited to fill the reservior using the top cap (I tried getting my fingers, a spanner and a pair of pliers in but just could not open the bottom cap - which I'm assuming is for the front reservior). Are the two reserviors connected? If I just fill the top, will it flow to the bottom to create a constant level for both front and rear reserviors?

I used a straw to fill where the top cap was (see picture 3) and I didn't fill right to the top but I am certain I filled it past the minimum line. I closed everything up and turned on the key. The wig wag started again (and not the regular wig-wag before the wheels start rolling). This morning on my way to work, the wig-wag started when I reversed the bike out of the driveway. I turned off the key and turned it on again, started the bike and rode off and the wig-wag went away... for a while. When I stopped at a light, I turned off the key again and restarted and a short while later the wig-wag started again.

I see what happens this evening on the way home from work. Prior to topping up the brake fluid, the wig-wag does not come on when I ride home from work - which suggested to me that it was a brake fluid level thing. Until about a week ago, sometimes the ride home would also have the wig-wag. This made me start to think that it could be more than just brake fluid. Brake pads perhaps?

Does anyone have any thoughts?

Should I go and buy the right size allan key(s) and try and remove the tupperware so I can fill both front and rear brake fluid reserviors?

Do I need to stop riding till this is resolved?

Any advice would be much appreciated.

Cheers,
Joseph

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Look at the depth of your threads on the ABS filler caps. The fluid should be close to the bottom of those threads. The hoses attached are for overflow. I would suggest drawing some brake fluid from the reservoir and looking at it. If it is dark, it's time to flush.

Not to discount other....and no doubt far more expert advice, but I had the same problem on my '96 R1100 RT and a new battery cured it. Don't know how similar the systems are....just my .02