Dripping Brake Lever

[Carguz]

After switching my RS bars to standard 100 bars on my 85 RS and after considerable suffering, everything works and the ride is now much more comfortable for me. I actually sit on the bike and am able to ride in a very relaxed and natural postion.

I still have problems however.

I of course switched the top brake hose, bled the brakes, etc.

I may have added a tad too much fluid as evidenced by a dripping lever (where the lever actually pivots during actuation). I bled out more fluid and am slightly under the max mark.

It drips less but still drips after a few hard stops.

The dripping fluid is a reddish rusty hue (although clean in the reservoir).

I'm sure this probably means some type of bad news and something probably needs to be rebuilt. (Would love to see go away if I bleed off more fluid...)

Any ideas, comments?

Carlos

[Bobmws]

When you bled the brakes, did you pull the lever all the way to the handgrip? If so you moved the piston seal further than it's normal range of travel in the cylinder, into an area that is most likely corroded. This has caused the seal to fail. You will have to replace or rebuild the master cylinder.

[deilenberger]

+1 on Bob's diagnosis.

I'd suggest a new master cylinder. If there is ugly red stuff dripping, the bore of the cylinder is likely corroded, and just replacing the seals isn't going to fix it. With the cylinder being almost 25 years old this isn't a huge surprise..

[zoridog]

Coincidentally, I need a new master cylinder for my airhead.

Would you believe there are none in the US ?!?! I need to order one from Germany! I hope you have better luck locating the one you need.

[kbasa]

Coincidentally, I need a new master cylinder for my airhead.

Would you believe there are none in the US ?!?! I need to order one from Germany! I hope you have better luck locating the one you need.

Is the bore corroded? If not, just rebuild it. You'll need a set of snap ring pliers and some emery cloth to get it apart and cleaned up.

WRT to the MC not being in the US, consider that for many other manufacturers, getting parts for a bike that's been out of production for 15+ years is just not possible.

[Carguz]

I thought I researched a previous post and saw there were no rebuild kits for this MC. Is this possible? What will I need? A piston and seals?

Any advise very welcome.

Thanks.

[cjack]

I thought I researched a previous post and saw there were no rebuild kits for this MC. Is this possible? What will I need? A piston and seals?

Any advise very welcome.

Thanks.

Both are in stock in the country. About $212 for the cylinder and piston, and about $57 for the piston/rebuild kit.

[cjack]

Coincidentally, I need a new master cylinder for my airhead.

Would you believe there are none in the US ?!?! I need to order one from Germany! I hope you have better luck locating the one you need.

That usually takes 10 days or so. Not a big deal...unless they have to go out and make one. They do that. The unbelievable thing is that BMW still supplies parts for BMWs that are 15, 30, and 60 years old. This one is also about $212.

[brickrider]

+1 on Bob's diagnosis.

I'd suggest a new master cylinder. If there is ugly red stuff dripping, the bore of the cylinder is likely corroded, and just replacing the seals isn't going to fix it. With the cylinder being almost 25 years old this isn't a huge surprise..

+1 on Don's diagnosis.

A lot depends on your luck. I never have good luck & success rebuilding something that old. The time just gets wasted and the rebuild parts end up being stored in a box for years.

I vote for the new master cylinder, if you're going to keep the bike + ride it a lot.

Ride Safely,
BrickRider

[wmubrown]

I've checked with a couple sources when my front master cylinder failed this year on the Gillette ride and was told there is no rebuild kit for it, there is only a rebuild kit available for the rear master cylinder. If that's not true, I'd sure like a part number or something because 3 dealers are unaware of such a kit.

[cjack]

I've checked with a couple sources when my front master cylinder failed this year on the Gillette ride and was told there is no rebuild kit for it, there is only a rebuild kit available for the rear master cylinder. If that's not true, I'd sure like a part number or something because 3 dealers are unaware of such a kit.

For the '96 K1100LT, the rebuild kit is 32 72 2 332 037 which is listed to only apply to the "anodized" cylinder 32 72 2 352 190. I don't know if you have to replace it once to get a "newer" anodized cylinder or when that started year wise. But, the rebuild kit (piston with rubbers) and the anodized cylinder (whole thing) are the only parts listed with out an in-date. The MSRPs are about $71 and $362 respectively.
Looks like the '94 LT is the same.

[98lee]

I've checked with a couple sources when my front master cylinder failed this year on the Gillette ride and was told there is no rebuild kit for it, there is only a rebuild kit available for the rear master cylinder. If that's not true, I'd sure like a part number or something because 3 dealers are unaware of such a kit.

They probably couldn't find it because it is listed in the "Steering" section (it's on the handlebars) not the "Brakes" section.


:dance :dance :dance

[jpberens43639]

It's not safe to ride anyways. Pull it apart & check the bore with a bright light.
Light corrosion & pitting can be cleaned up.

My 93 K1100RS is completly different as it's simple to take apart.

My bore was corroded and the REAL cuprite was the poor outer seal design.

I dressed the bore with just emory paper, moving to 220 grit, then 280, then 340, then 000 steel wool till the ENTIRE bore as far in as I could get was smooth as glass. Cleaned it all up with alchohol.
New piston lubed with DOT 4, then reassemble, refill, bleed, enjoy. not EVEN a weep 2 months & 5,000 miles later.

Used the original outer seal boot. Cleaned it up very ver well, then used Permatex ' FormaGasket " to refit it and hold it in place.

As always, change the fluid in the fall, then again in the spring.

I find it very very hard to beleive someone does not make a rebuild kit for that

Check out " Beemer Boan Yard " I think they have what you need.

" http://www.beemerboneyard.com/32722302356.html "

[cjack]

They probably couldn't find it because it is listed in the "Steering" section (it's on the handlebars) not the "Brakes" section.


:dance :dance :dance

I doubt it since that is where almost all the front master cylinders are located. To be fair, they probably had an issue with the "anodized" cylinder, not knowing if it was an upgrade, when or what, and preferred to sell a complete one. Or maybe they did what I did as I checked the part # for old part #'s and found one (ends in 140) that expired in '99. So it is a good chance that the cylinder was upgraded in '99, and the kit is only available for the new one (the 190 part #).
SO...wmubrown, if you bought the whole cylinder this year, you are good to go with a rebuild next time.

[wmubrown]

For the '96 K1100LT, the rebuild kit is 32 72 2 332 037 which is listed to only apply to the "anodized" cylinder 32 72 2 352 190. I don't know if you have to replace it once to get a "newer" anodized cylinder or when that started year wise. But, the rebuild kit (piston with rubbers) and the anodized cylinder (whole thing) are the only parts listed with out an in-date. The MSRPs are about $71 and $362 respectively.
Looks like the '94 LT is the same.

As usual Jack, you're a fountain of information! THREE dealers could not find a rebuild kit. Someone did mention the 'changeover' in design however... so maybe they didn't want to take the risk that I had the older style? Which I probably did. And I did buy a whole new MC so its good to know I can rebuild it next time... which will probably be another 11 years from now... ;)

I just bought Speigler SS brake lines to add this winter too... the original brake lines have a lot of wear on them... not sure why, when I tear it apart maybe something will reveal itself - like the front fender has been rubbing on the brake lines or something.

[Carguz]

Picked the whole unit up on ebay for $21. (no typo)

Everthing there, everything works! cables, throttle, brake switch, MC, etc.

Sometimes, you do get lucky.