First problem

[mikesim]

After 137,000 miles, Traveller presented me with his first problem other than routine maintenance. I filled up the tank with fuel in preparation for an upcoming ride. I noticed that the rear brake didn't seem like it was very effective but I assumed it was from infrequent use over the last several months. When I got home I parked the bike, went in and ate lunch and came back outside to give it a good cleanup and detail for my ride. When I checked the tire pressures, I noticed a puddle of clear fluid on the right side of the wheel. I felt the fluid and determined it was brake fluid. I crawled under the bike as best I could and could trace the path of the fluid tracking down the rotor from the caliper. I activated the brake pedal by hand and could see some weepage from the caliper. I'm going to dive into it tomorrow and see what the problem is. No one likes bike problems, but I can't complain too much after 12 years of ownership and 137K trouble free miles. I am keeping my fingers crossed that it is something simple.

Mike

 

[ST1100Y]

...12 years of ownership and 137K...

And never took the time to overhaul them calipers...?!

Likely the pistons suffered pitting corrosion and chewed up the rings...
I'd prepare for new pistons, rings and some intensive cleaning of caliper bores and ring-grooves...

 

[mikesim]

I've done several fluid flushes over the years but have never found it necessary to overhaul the calipers due to corrosion or leakage. Whenever the pads are replaced I take a peek at the calipers and make sure they compress correctly. I'll find out more when I tackle the problem. If the problem is as you suspect then I will also do the front calipers forthwith.

Mike

 

[ST1100Y]

...overhaul the calipers due to corrosion or leakage...

Way to late...
Wheel removal and pad replacement are good moments for cleaning and checking condition of calipers...
And once I feel noticeable resistance when pushing the pistons in (fingers over rotor, thumbs on caliper casing) I knock them apart to clean the grooves, install new rings etc...

 

[mikesim]

Way to late...
Wheel removal and pad replacement are good moments for cleaning and checking condition of calipers...
And once I feel noticeable resistance when pushing the pistons in (fingers over rotor, thumbs on caliper casing) I knock them apart to clean the grooves, install new rings etc...

I do inspect the calipers from time to time as you suggest and this is the first time I have ever had problems with any caliper or wheel cylinder for that matter on any vehicle I have owned. When the pads are replaced, I compress the pistons and they have always compressed smoothly and completely with no problem. I am a big believer in preventive maintenance hence the periodic brake fluid flushes that I do. I don't however go looking for a problem that isn't there. If there are no visible or physical malfunctions in a system, I don't mess with it. I agree with the old adage, "if it ain't broke, don't fix it."

In my particular case, the caliper is leaking badly so I intend to replace it as an assembly and due to the mileage and the labor involved, I intend on proactively replacing the master cylinder as well.

Mike

 

[ST1100Y]

When the pads are replaced, I compress the pistons and they have always compressed smoothly and completely with no problem.

That wasn't clear at the beginning...
Astonishing that it developed a fatal leakage... already curious about the culprit...

 

[Coyote Chris]

Over those years and 137,000, this does not surprise me at all.... I also suspect that his climate is fairly humid at times....if you think about it, most moving parts on an NT have some point a failure that will occur...you just dont know what that is....there is a Mean time between Failure for many things.... but that is a mean time....so when is his fuel pump going to go? Next week or 10 years? Maybe his fuel injectors will go another 100,000 miles....maybe not....then there is the crank position sensor....anyone ever replace a water pump in a vehicle?