[Felix]

Don't forget the clutch slave (actuator)! They wear out and when they do, they leak the clutch fluid into the bell housing, which contaminates your clutch plates and attacks exposed rubber seals in that area. I agree with the Viton ring and engine seals, but when you do this job, replace the clutch slave, too. Stay away from the cheap aftermarket ones. Insist on using the BMW part that is made by Magura.

 

[Felix]

The way you explain the procedure would have you riding the bike with bottle of Coke dangling underneath the bike. Shouldn't the ride take place after the Coke has been injected?

How long will this fix last?

 

[Felix]

... drill a hole upwards into the bottom of the clutch housing ... Coca-cola has to be above the clutch for gravity drain.

This doesn't make sense to me. How can the coke be above the clutch, if the hole and fill tube are attached beneath the clutch?

 

[Felix]

About how far into the bell housing should the tube be inserted, e.g. 50mm, 200 mm, or doesn't it matter? Before shooting Coke into the bell housing, I'd think that it'd be good to first allow whatever clutch fluid that's in there to drain through the new hole, and if possible to flush it all out with some solvent, like brake cleaner. For that, I'd want to be sure the hole was at the lowest point.

The reason I'm interested is because I experienced a slave cylinder failure with my oilhead while touring a few years ago, and lost clutch function while still 300 miles from home. Having the same design clutch as the K-bike, I could have used this fix. Thanks for the tip!

 

[Felix]

2. If I experience a slipping clutch due to this failure, how long to I have before I’m stuck beside the road (in miles) looking for a place to buy a drill & Coca-Cola!
Unless there’s a tame Beemer shop nearby to tear it apart for me & I’ll find a motel with swimming pool meanwhile!

Think of it as how many clutch pulls, rather than miles. If you're in cities or backroads where you're shifting gears a lot, then you're not going to get very far. But if you're on an interstate highway, and droning along in top gear, gas tank to gas tank stops, you'll ride all day long.

In my case, I was ferrying the bike to Dallas, Texas from Baltimore, Maryland. It was new to me as I had just bought it used. I was unfamiliar with the bike's clutch (they're all a bit different as you probably know). Before I realized that the clutch was slipping, I was already up on the Blue Ridge Parkway, flogging the heck out of the bike, and then detouring through Roanoke, Virginia city streets due a parkway closure. Once I realized what was happening, I got on the Interstate hoping to make a beeline for home. I made it all the way to Ruston, Louisiana, before having to park it for good and get assistance.

Assuming that the slave cylinder was already leaking a bit when I took delivery of the bike, that's about 1550 miles of a mix of twisty mountain roads and Interstate highways before failure, the last 1100 miles of which were solely on the Interstates. I think that If I had just rode the Interstates instead of going up into the mountains to play, I could have made it all the way home and barely even noticed the problem. It was the mountain roads of Virginia that really did me in.

 

[Felix]

I'll add that if your slave cylinder is more than 10 years old, regardless of mileage, or if it's got 30k miles regardless of age, then spend a few hours and $100, and change it. This is an ounce of prevention, especially if you're planning to go off and play for a week in the mountains. Get the quality Magura unit from BMW and not one of the cheaper alternatives.