Thanks, Joe. I'll take a look later.
I also belive the spring gets weak, although I can't prove that.Great photos, Chuck. Thanks. It shows the rotating ball for the articlulation. I knew there was some kind of join. Funny that the issue has nothing to do with the plunger...well, unless it's the corrosion is a result of water leaking around the top seal???
If the seals are not leaking brake fluid it is unlikely water is leaking in past the seals under atmospheric pressure. Pack the boot with grease if it makes you feel better however the downward tilt of the SMC with outlet holes at its lower end coupled with the heat from the attached caliper is going to concentrate moisture & air in the SMC bore with no way for it to get out until the flushes are carefully done by the book. I believe it is the combination of air and moisture left in the bore that creates the conditions for corrosion to happen.Great photos, Chuck. Thanks. It shows the rotating ball for the articlulation. I knew there was some kind of join. Funny that the issue has nothing to do with the plunger...well, unless it's the corrosion is a result of water leaking around the top seal???
Glad this event worked out and no one was injured.Dave...I am very good about changing fluids and always do them at or before scheduled in the manual. I had just flushed both clutch and brakes about 5,000 miles before this happened.
Very good information. I know you ride alot and this bike isn't a garage queen. How many miles on the bike?Ok...Ted called about the SMC part. Honda does have a new part specificly to replace the SMCs older than the update.....so Joe, we use the old caliper.
Second....I talked to Ted about the corrosion issue and here's what he and Honda say: Looking at Chuck's images, you'll see two flange seals on the internal piston....the bottom seal (to the right on Chuck's photo) and the top seal (to the left on Chuck's photo). The bottom seal's job is to keep the brake hydraulic circuit sealed and pressurized. The top seal works to keep moisture and dirt out of the system. There are two additional sealing mechanisims, both at the top end (connecting rod) to keep water and dirt out.......1. the external boot 2. a seal under the retainer clip. All three defenses against water and dirt....eventually fail. The corrosion occurs at the TOP inside cylinder seal area.....and has nothing to do with the inside (bottom) seal keeping the brake's hydraulic system from leaking. Honda added the slot/trough in the new SMC as a 4th defense against the water/dirt problem.
Thanks for those photos, Chuck. Things made a lot of sense after talking to both Ted and the American Honda regional rep about this stuff.
I've looked at the brake schematics and always wondered if this rear brake stomping would work to push the piston back. Have you tried it yourself or seen it work? That could be a very useful tip.Forest, that was bad...glad it wasn't worse!
Thanks for the info - your thread joins a list of similar problems experienced by several people. I've seen this same problem on a local ST in the past (not mine). Normally, stomping on the rear brake --while stopped-- will temporarily release the SMC (push the plunger back out)...at least until the next braking action occurs while the bike is moving.
Thank you for the information. Good to know. I will now purchase a new secondary master cylinder for the Bin-o-parts box.Dave and Bob....I ALWAYS flush the systems "by the book"....and I'm careful and precise when I do the job.....
Yeah, bleeding off the rear brake would get you home but in the process probably mess up your wheels and any paint and also might get on the tire and make things just as bad/slippery. Another option would be to put something between the smc and fork to block it's movement but that seems a bit dangerous as well.Then we'd have to figure out how to disable the rear brake. We would still have the four pistons on the front to get us limping home. Bleeding off the line to the rear caliper would work but is messy on the road.
That would be nice and easy... course you could just cut the mounting connector offMaybe there is a part on the SMC actuator that could be removed so the SMC piston is no longer compressed while braking?