So, Larry cured the howling and in the process made your '06 like new again.
Well done Larry.
Well done Larry.
"Howling" noise when using the brake pedal
- Thread starter Elevenjack
- Start date
OP
OP
Affirmative!
First off, thank you for the kind words, and allowing me to assist you in sorting your bike out 
Believe it or not folks, his reply was the short version
Mine may be a little longer (rambling included)
When I saw the condition of the front end, blown seals, leaking oil, soaked pads, and filthy calipers....I did what I usually do....I took his bike Hostage
I must admit, his request was to stop the bike from howling, but I got sorta side tracked seeing so many other things that needed repair, and went OCD on the poor man
The front calipers were completely packed with oil and dirt, and the thick (rear) EBC pads that were installed in the front calipers were dragging on the rotor and did not have enough room or clearance to back away, thus the normal dragging of the rear brakes etc. Except it wasn't quite that easy....He said he rebuilt the SMC so the first time around, I didn't inspect it close enough....my bad.
The SMC was not letting fluid pass over to the PCV, or at least not enough....The stuff that came out was really nasty and brown, with bits of crap floating in the line
. The blue cartridge in the back of it was clogged up. When I opened the SMC up, we found that the local shop had provided him with the wrong rebuild kit. Not only was it too long, the piston was sticking in the bore a bit. Order a new SMC was the suggestion, which he accepted. While we were waiting for parts, I completely detail stripped both the front calipers and replaced all the seals and dust covers, and polished the pistons, I also removed the wedge shaped EBC pads (sign the SMC was dying) and replaced them with OEM Honda pads that I had in stock.
I then noticed that the forks were quite a bit out of alignment, and the axle would not turn freely by hand when inserted into the forks. Both forks were removed and completely rebuilt with new seals, crush washers, and o-rings, and oil, and one fork cap that was found damaged.
The front end was then plunged and aligned correctly, verified by the axle turning freely and sliding from side to side freely.
Wheel bearings were inspected, SMC needle bearings packed with water proof grease, and a new SMC was installed. The entire system was flushed/bled again....
The noise was still there!
Somewhere in the middle of all this confusion, I did remember servicing the pre-load adjuster, and setting his damping adjustment.
We lifted the tank, and found his K&N filter was crushed down, and was letting all kinds of crap through, so I suggested he throw it away and pulled a new OEM one out of my tool box.
We replaced all the vacuum lines, cleaned the 5 way tee, and sync'd the throttle bodies (sic). His bike was not too far off, but I was able to dial it in enough to get all the readings on a single small line on the Morgan Carb Tune.
And yes....I balanced the nickel.
While we were under the hood, I cleaned and tightened his ground wires, and moved his throttle adjustment down below to give him more room at the grip.
I also adjusted and lubed his throttle cable, and idle cable. Tightened a few loose hose clamps that could be reached from the top, and verified that there were no critters living under there.
I checked all the critical fasteners, brought everything back to the proper specs, and adjusted his counter balancer(s), then moved back to the rear wheel again.
As he said, his Driven Flange Bearings were toast! The were spinning in the hub, and turned it into the most beautiful color case hardened finish of an old single action colt revolver.
The Flange bearings were replaced, as well as the collar they rode on.
All the rear o-rings were replaced, the one on the backside of the splines was flat, and starting to allow the metal to score on the hub etc. NO moly paste was found anywhere, on either side of the splines, this was addressed, and the correct moly PASTE was used (not the M77) we used the loctite stuff
Wheel bearings were fine, the dampers were cleaned and treated with rubber dressing, and the rear end was put back together at this point.
I was told that the rear caliper was completely rebuilt, so I just verified everything was clean, and installed correctly, and put it back together...
Test ride....still has the noise
Everything came apart again....entire system flushed/bled several more times.....still we had this fingernails on a chalkboard noise, and vibration that you could feel in the pegs.
Everything came apart again...At this point I am inspecting parts with a jewelers loop.
The clips appeared straight, the guide rods appeared straight at a glance, however, the smaller one looked like it may be pointing downward just a bit.
Out comes the paint pencil...I pulled the stopper bolt, painted it, and put everything together yet again, and took it for a test ride....
When I pulled it apart again, I found that the stopper bolt was scoring in the middle of the plug on one side, and the very tip on the other, indicating that something was half a bubble off plumb.
It was at this point that we noticed the rear boot, was "different" I pulled a new one out of my parts supply, swapped it out, put it back together, another test ride....better, but still no joy
We decided to order a new caliper bracket at this point. Bob was kind enough to ship me a used one, however, it probably came off a bike for the same issues we were having
Thanks for at least trying to help Bob. The owner ordered a new bracket, and the wait began....
This is where things started coming into focus....something caught my eye when I was comparing the two brackets on the bench (Bob's and the owners) Inside the egg shaped hole where the plug sits, the aluminum surface was scored in a spiral shaped flutes if you will. The ledge that holds the small silver clip was also smeared down with a large gap on the inboard side, allowing the clip to tilt...I believe this damage happened when the brakes locked up and the weight of the bike pushing against the pads/caliper damaged it.
What it also damaged, that was not visible to our eyes, was, the smaller steel guide rod, was pushed into the soft aluminum bracket, approximately one thread, thus tilting the whole shebang, enough to cause the pistons to hit edge first on the rotor (howling), then going away when the two other pistons squared it up, then it would not allow the pistons to release and return to their at rest position, causing drag and lockup.
I over looked this two or three times When the new bracket arrived, I installed it, put everything back together, flush/bled the system one more time, just because, held my breath, crossed my fingers, said a prayer, 
and headed out on yet another test ride....NO NOISE! 
I came back after about a 20 mile test ride and found I could breath again. I pulled the stopper bolt, and the wear (witness mark) was even on both sides, and no signs of flutes in the new caliper bracket. The caliper slides back and forth with ease, and after 20 miles of testing the brakes repeatedly, I was able to stop, put the bike on the center stand, and get almost 3 full revolutions out of the rear wheel with no noise what so ever!
And to think, I was about to shoot his bike
So, IF anyone is having ANY kind of brake dragging issues, and you've removed the SMC, Pads, Clips, Flush/Bleed, and all the normal trouble shooting stuff....look inside the rear caliper where the stopper bolt rests and see if you see flutes or damage, that would indicate that your guide dowel is bent/crooked
It is unknown, what caused the damage....was the axle tightened first? was the stopper bolt loose? wrong pads? any or all of these things? or was it damaged due to the brakes locking up?
We may never know, but at least now, its one more thing that folks can look for when searching for causes of their brakes dragging.
This has been a good learning experience for me, and one that I can share with all you.
Believe it or not folks, his reply was the short version
Mine may be a little longer (rambling included)
When I saw the condition of the front end, blown seals, leaking oil, soaked pads, and filthy calipers....I did what I usually do....I took his bike Hostage
I must admit, his request was to stop the bike from howling, but I got sorta side tracked seeing so many other things that needed repair, and went OCD on the poor man
The front calipers were completely packed with oil and dirt, and the thick (rear) EBC pads that were installed in the front calipers were dragging on the rotor and did not have enough room or clearance to back away, thus the normal dragging of the rear brakes etc. Except it wasn't quite that easy....He said he rebuilt the SMC so the first time around, I didn't inspect it close enough....my bad.
The SMC was not letting fluid pass over to the PCV, or at least not enough....The stuff that came out was really nasty and brown, with bits of crap floating in the line
. The blue cartridge in the back of it was clogged up. When I opened the SMC up, we found that the local shop had provided him with the wrong rebuild kit. Not only was it too long, the piston was sticking in the bore a bit. Order a new SMC was the suggestion, which he accepted. While we were waiting for parts, I completely detail stripped both the front calipers and replaced all the seals and dust covers, and polished the pistons, I also removed the wedge shaped EBC pads (sign the SMC was dying) and replaced them with OEM Honda pads that I had in stock.I then noticed that the forks were quite a bit out of alignment, and the axle would not turn freely by hand when inserted into the forks. Both forks were removed and completely rebuilt with new seals, crush washers, and o-rings, and oil, and one fork cap that was found damaged.
The front end was then plunged and aligned correctly, verified by the axle turning freely and sliding from side to side freely.
Wheel bearings were inspected, SMC needle bearings packed with water proof grease, and a new SMC was installed. The entire system was flushed/bled again....
The noise was still there!
Somewhere in the middle of all this confusion, I did remember servicing the pre-load adjuster, and setting his damping adjustment.
We lifted the tank, and found his K&N filter was crushed down, and was letting all kinds of crap through, so I suggested he throw it away and pulled a new OEM one out of my tool box.
We replaced all the vacuum lines, cleaned the 5 way tee, and sync'd the throttle bodies (sic). His bike was not too far off, but I was able to dial it in enough to get all the readings on a single small line on the Morgan Carb Tune.
And yes....I balanced the nickel.
While we were under the hood, I cleaned and tightened his ground wires, and moved his throttle adjustment down below to give him more room at the grip.
I also adjusted and lubed his throttle cable, and idle cable. Tightened a few loose hose clamps that could be reached from the top, and verified that there were no critters living under there.
I checked all the critical fasteners, brought everything back to the proper specs, and adjusted his counter balancer(s), then moved back to the rear wheel again.
As he said, his Driven Flange Bearings were toast! The were spinning in the hub, and turned it into the most beautiful color case hardened finish of an old single action colt revolver.
The Flange bearings were replaced, as well as the collar they rode on.
All the rear o-rings were replaced, the one on the backside of the splines was flat, and starting to allow the metal to score on the hub etc. NO moly paste was found anywhere, on either side of the splines, this was addressed, and the correct moly PASTE was used (not the M77) we used the loctite stuff
Wheel bearings were fine, the dampers were cleaned and treated with rubber dressing, and the rear end was put back together at this point.
I was told that the rear caliper was completely rebuilt, so I just verified everything was clean, and installed correctly, and put it back together...
Test ride....still has the noise
Everything came apart again....entire system flushed/bled several more times.....still we had this fingernails on a chalkboard noise, and vibration that you could feel in the pegs.
Everything came apart again...At this point I am inspecting parts with a jewelers loop.
The clips appeared straight, the guide rods appeared straight at a glance, however, the smaller one looked like it may be pointing downward just a bit.
Out comes the paint pencil...I pulled the stopper bolt, painted it, and put everything together yet again, and took it for a test ride....
When I pulled it apart again, I found that the stopper bolt was scoring in the middle of the plug on one side, and the very tip on the other, indicating that something was half a bubble off plumb.
It was at this point that we noticed the rear boot, was "different" I pulled a new one out of my parts supply, swapped it out, put it back together, another test ride....better, but still no joy
We decided to order a new caliper bracket at this point. Bob was kind enough to ship me a used one, however, it probably came off a bike for the same issues we were having
Thanks for at least trying to help Bob. The owner ordered a new bracket, and the wait began....
This is where things started coming into focus....something caught my eye when I was comparing the two brackets on the bench (Bob's and the owners) Inside the egg shaped hole where the plug sits, the aluminum surface was scored in a spiral shaped flutes if you will. The ledge that holds the small silver clip was also smeared down with a large gap on the inboard side, allowing the clip to tilt...I believe this damage happened when the brakes locked up and the weight of the bike pushing against the pads/caliper damaged it.
What it also damaged, that was not visible to our eyes, was, the smaller steel guide rod, was pushed into the soft aluminum bracket, approximately one thread, thus tilting the whole shebang, enough to cause the pistons to hit edge first on the rotor (howling), then going away when the two other pistons squared it up, then it would not allow the pistons to release and return to their at rest position, causing drag and lockup.
I over looked this two or three times
When the new bracket arrived, I installed it, put everything back together, flush/bled the system one more time, just because, held my breath, crossed my fingers, said a prayer, and headed out on yet another test ride....NO NOISE! I came back after about a 20 mile test ride and found I could breath again. I pulled the stopper bolt, and the wear (witness mark) was even on both sides, and no signs of flutes in the new caliper bracket. The caliper slides back and forth with ease, and after 20 miles of testing the brakes repeatedly, I was able to stop, put the bike on the center stand, and get almost 3 full revolutions out of the rear wheel with no noise what so ever!
And to think, I was about to shoot his bike
So, IF anyone is having ANY kind of brake dragging issues, and you've removed the SMC, Pads, Clips, Flush/Bleed, and all the normal trouble shooting stuff....look inside the rear caliper where the stopper bolt rests and see if you see flutes or damage, that would indicate that your guide dowel is bent/crooked
It is unknown, what caused the damage....was the axle tightened first? was the stopper bolt loose? wrong pads? any or all of these things? or was it damaged due to the brakes locking up?
We may never know, but at least now, its one more thing that folks can look for when searching for causes of their brakes dragging.
This has been a good learning experience for me, and one that I can share with all you.
Last edited:
ToddC
Site Supporter
Wow...!! Just...wow! 
OP
OP
I knew you’d break it down better than me!
Gus1300
Site Supporter
I don't think my bike is in bad shape, but I sure would like you to have it for a good once over, just to see how good it MIGHT be afterward! Well done, and an impressive read! Thanks for the educational write-up and documentation of what you found for us all to learn from.
Now, that wasn't so hard, was it?
Once again, well done.
Once again, well done.
skipcurt
Skip
Another satisfied customer. Soon your garage is going to have an OCD Enterprises sign like McDonald's statement..."over xxxx served".
Skip
Skip
hmmmm. i am having the howl. i think some of this is the there is constant applied pressure on the pistons. Pistons have been polished and seals have been thoroughly cleaned. i can presses the rear caliper piston with a simple press of my fingers.
i'll have to give this a look at this bracket. problem i am having is the SMC plunger gets bound up even after through cleaning and proper bleeding. (Ill have to open up th eplastic plunger). I am finding my rear caliper is about 3-4 times hotter that the front. all with Honda pads. I do tend to find the rear caliper bracket when grabbed i can rock it and can hear what could be the source of the howl
i'll have to give this a look at this bracket. problem i am having is the SMC plunger gets bound up even after through cleaning and proper bleeding. (Ill have to open up th eplastic plunger). I am finding my rear caliper is about 3-4 times hotter that the front. all with Honda pads. I do tend to find the rear caliper bracket when grabbed i can rock it and can hear what could be the source of the howl
Standing by the
+1 on this question. The wear pattern (spiral flutes),,, indicates misaligned movement. Just trying to envision how this movement occurs. Suggest that the movement is part of the design. If it is misaligned, it can howl and cause the spiral pattern. If it is not misaligned,, it still moves,, but does not exhibit the howl or spiral pattern. But why,, is there movement here,,, ?? I thought the stopper bolt was just too counter rotation of the caliper assembly under braking load. But it has a slotted hole in the bracket,, and so is obviously designed to accommodate movement,, as is also evidenced by the pitch of the spiral pattern. Got to go have a look, and a head scratch,,,, CAt'
My guess is that it has to do with the vibration caused by the caliper's misalignment grabbing the disk unevenly. I'll use an example that might be similar. Do you know why gravel roads have the washboard ridges? It is due to the resonant frequency of automobiles' suspension. The bouncing wheels abrade and pile up gravel/dirt as the car drives down the road. I think these flutes were caused the same way - by vibration and a combination of the resonant frequency of said vibes.
Lots of good questions and comments guys
Its just a guess, but if you go back to post 23 and look at the 3rd picture, it may make more sense.
You'll notice that the short arm (right side of the picture) of the bracket just hangs there and is not supported as the left side it.
I'm finding more and more brackets fretted away or worn down on that side, causing the retaining clip to tilt and/or vibrate (this may be the resonant frequency vibration that causes the flutes?)
You'll also notice on the 3rd and 4th picture that the clip's raised retaining bumps are smashed flat due to this movement.
So far its been my findings that when the SMC gives up the ghost, that it usually takes the rear bracket with it.
When the retaining clip area gets worn and sloppy, and allows the clip to move around or vibrate, this causes several things to get half a bubble off plumb.
Perhaps, (just a guess) the wear tilts the clip, which may apply uneven pressure from the pads to the pistons, causing vibrations, wear, and the "fingernail on a chalkboard" howling?
Its just a guess, but if you go back to post 23 and look at the 3rd picture, it may make more sense.
You'll notice that the short arm (right side of the picture) of the bracket just hangs there and is not supported as the left side it.
I'm finding more and more brackets fretted away or worn down on that side, causing the retaining clip to tilt and/or vibrate (this may be the resonant frequency vibration that causes the flutes?)
You'll also notice on the 3rd and 4th picture that the clip's raised retaining bumps are smashed flat due to this movement.
So far its been my findings that when the SMC gives up the ghost, that it usually takes the rear bracket with it.
When the retaining clip area gets worn and sloppy, and allows the clip to move around or vibrate, this causes several things to get half a bubble off plumb.
Perhaps, (just a guess) the wear tilts the clip, which may apply uneven pressure from the pads to the pistons, causing vibrations, wear, and the "fingernail on a chalkboard" howling?
Last edited:
So Larry's been helping me with a brake bleed after replacing my SMC subassembly.
My original thread
www.st-owners.com
But thanks to this thread, look what I found after taking off my rear wheel for caliper cleaning....
It does not seem that mine is quite as shot as the OP.
Are there any pictures of what the clip looks like on a brand new bracket? Trying to decide if I need to buy a new one.
Thanks!
My original thread
Rear Brakes dragging - SMC questions | ST1300-Brakes
I just noticed that my rear brake is dragging. Sigh. No Damage yet. I have a 2004 ABS w ~ 70K miles that to my knowledge has not had any work done to the SMC….so I suppose I’m due for that….I suppose being in Arizona kept moisture out of there this long. Starting noticing this the day after a...
But thanks to this thread, look what I found after taking off my rear wheel for caliper cleaning....
It does not seem that mine is quite as shot as the OP.
Are there any pictures of what the clip looks like on a brand new bracket? Trying to decide if I need to buy a new one.
Thanks!
ST1100Y
Site Supporter
So can the root-cause of the whole mess be determined as infrequent/improper fluid replacement/flush?The SMC was not letting fluid pass over to the PCV, or at least not enough....The stuff that came out was really nasty and brown, with bits of crap floating in the line