Another Brake Issue

[ThruST]

I hate to start another brake drag thread but here it goes. 06 ST with 16000 miles. Changed the tires, installed new brake pads, bleed the brakes, everything seemed fine. Was riding one day and felt what is believed to be a rear brake drag, this happened after applying brakes and was felt while coasting. Seems to be a pulsing drag I feel it about three times then it goes away and does not happen all the time. Did the brake bleed again, same intermittent issue, reinstalled old rear brake pads (plenty of life left on them) thought I fixed the problem 3 days passed then was coasting up the driveway after a ride and felt that 3 pulse drag. OK so i have read the threads about the SMC failures seems this issue points in that direction. While looking at the bike with another ST owner we compared the SMC operation on the two bikes (pushing by hand gauging rear brake application) and we agreed that the operation is similar. NOW FOR THE DIFFERENCE. While operating the rear brake pedal (does not occur while applying front brake lever) a ticking sound can be heard from the front of the bike. This happens when pressure is released from the foot pedal, operating the foot pedal by hand in the bottom 1/4 inch to travel the ticking sound can be heard at each release of pressure (speed of application or amount of force applied does not seem to matter) The ticking sound seems to be coming from the DELAY VALVE, Seems Ma Honda deems it unnecessary to provide a theory of operation in the manual, it only gives R&R instructions.
ARE THERE ANY IDEAS OUT THERE??????? NEED INPUT PLEASE!!!!!!

The bikes is still under warranty, but I have no faith in the 25 year olds working in the local Honda shop, seems they have no knowledge of ST's.

Thanks
Mike

 

[Mellow]

With all due respect... since this started AFTER the brake bleeding... and IF IT WERE ME, I'd tend to think I didn't perform the procedure correctly. Are you sure you followed the correct sequence when doing that brake fluid bleed.

 

[ThruST]

Yep, gonna try it again with a pressure bleeder. Just trying to see if anyone has run across this ticking from the DELAY VALVE. Got a call into the Honda service rep for this area to pick his brain.

 

[Igofar]

Yep, gonna try it again with a pressure bleeder. Just trying to see if anyone has run across this ticking from the DELAY VALVE. Got a call into the Honda service rep for this area to pick his brain.

The pressure bleeder may just cause you more grief. The easiest way to bleed this system I've found, is with the motion pro easy bleeder, or stockton tool company bleeder.
But like Mellow said. You MUST follow the correct procedure to the letter. Check out the brake bleeding artical by milehigh or several other members here, myself included. You'll find a wealth of knowledge between all of us.
Don't be surprized that the rear brake lever causes problems up front. It too, works pistons on the front wheel when applied.
As far as bleeding...bleeding ABC..short version: Did you drain the handlebar mastercylinder and clean it before refilling with clean fluid? Did you bleed the front upper left first, then the front upper right?
Did you clean the diaphram with alchohol before closing it up?
Next, did you remove the left caliper and tilt it as directed? Then bleed the PCV on the right side next to the gas tank? This is bled from the rear master cylinder and the foot lever.
Next, did you bleed the rear caliper, most forward valve next?
Did you then bleed the front wheel, right, lower bleed valve?
Then pack the needle bearings with grease on the left caliper bracket, then remount it and bleed the left front lower bleed valve?
Lastly, the only one left is the rear wheel, farthest to the rear bleeder.
Did you remove the front pads and clean all the pistons before you started?
You may have an rattle clip loose or crooked, or a dry caliper hanging pin?
The last thing I do is clamp the lever(s) in the on position for a hour or so to bleed out the micro bubbles you can't see.
If the lever is soft, Sometimes I clamp them overnight. I always have a hard lever in the morning
I've found several pitted and corroded SMC units. Doing the, spin the wheel, squeeze the caliper and it should stop, etc.
does not always show the damage. The pitting is inside the caliper tube or housing.
You could gently try to pull back the rubber boot with your fingers and see if its packed with dirt, water, pond scum, etc.
If it looks nasty under the boot, you can bet your SMC will be toast.
The good news, they are a simple replacement part for about $100 bucks, or if the inside isn't too bad, you can purchase
the rebuild kit for about $35 dollars. Very simple to do.
Good luck.

 

[wes_van]

I have just run into the same problem as Thrust, with one slight difference. I replaced the SMC on my bike and bled the entire braking system after doing so. This was last fall, just before I parked it for the monsoon season here and did manage to test ride the bike and all seemed well. Yesterday we finally had some decent weather so I'm out for maybe a 60 km ride, rolling to a stoplight I apply the rear brake and get some brake noise. I get home and am pushing the bike BACKWARDS and I get the same brake drag type noise I had before the SMC replacement. Any thoughts on this? I understand that brake noise while pushing the bike backwards can be one symptom of the SMC going south, but I'm stumped with this. I'm also a little confused with the correct brake bleeding sequence, I followed this one and it seems there is more than one sequence out there.
1. LF caliper - top bleeder
2. RF caliper - top bleeder
3. Remove and tilt LF caliper 15 degrees
4. Proportioning control valve bleeder
5. Rear caliper front bleeder
6.Reinstall LF caliper
7. RF caliper - lower bleeder
8. LF caliper - lower bleeder
9. Rear caliper - rear bleeder

Any thoughts or advice would be welcome.

Mike

 

[st1300r]

"I understand that brake noise while pushing the bike backwards can be one symptom of the SMC going south"

Huh? I missed that one. Is there a link that explains that, that you can find.
Note it is normal for some brake contact. How hot was the disk at the end of the ride. Hotter than the front (typical) or burn you hot?

 

[wes_van]

https://www.st-owners.com/forums/showthread.php?106891-Symptoms-of-Your-SMC-going-South!

Try this link st1300r.

 

[Igofar]

I have just run into the same problem as Thrust, with one slight difference. I replaced the SMC on my bike and bled the entire braking system after doing so. This was last fall, just before I parked it for the monsoon season here and did manage to test ride the bike and all seemed well. Yesterday we finally had some decent weather so I'm out for maybe a 60 km ride, rolling to a stoplight I apply the rear brake and get some brake noise. I get home and am pushing the bike BACKWARDS and I get the same brake drag type noise I had before the SMC replacement. Any thoughts on this? I understand that brake noise while pushing the bike backwards can be one symptom of the SMC going south, but I'm stumped with this. I'm also a little confused with the correct brake bleeding sequence, I followed this one and it seems there is more than one sequence out there.
1. LF caliper - top bleeder
2. RF caliper - top bleeder
3. Remove and tilt LF caliper 15 degrees
4. Proportioning control valve bleeder
5. Rear caliper front bleeder
6.Reinstall LF caliper
7. RF caliper - lower bleeder
8. LF caliper - lower bleeder
9. Rear caliper - rear bleeder

Any thoughts or advice would be welcome.

Mike

Off the top of my head, your procedure looks correct. the only difference, I leave the left caliper tilted until I have to bleed that caliper.

 

[ThruST]

Guess What??? it was the SMC!!!!!! Who knew!!!!!

 

[jnsgardner]

Anybody have the part number or numbers for a SMC replacement? Direct Line's micro-fiche has a sub assembly that includes parts that are probably just fine. Is it just the guts that need replacing? I have a number of the 17 issues listed in the 'SMC going south' thread.

John

 

[Igofar]

I have just run into the same problem as Thrust, with one slight difference. I replaced the SMC on my bike and bled the entire braking system after doing so. This was last fall, just before I parked it for the monsoon season here and did manage to test ride the bike and all seemed well. Yesterday we finally had some decent weather so I'm out for maybe a 60 km ride, rolling to a stoplight I apply the rear brake and get some brake noise. I get home and am pushing the bike BACKWARDS and I get the same brake drag type noise I had before the SMC replacement. Any thoughts on this? I understand that brake noise while pushing the bike backwards can be one symptom of the SMC going south, but I'm stumped with this. I'm also a little confused with the correct brake bleeding sequence, I followed this one and it seems there is more than one sequence out there.
1. LF caliper - top bleeder
2. RF caliper - top bleeder
3. Remove and tilt LF caliper 15 degrees
4. Proportioning control valve bleeder
5. Rear caliper front bleeder
6.Reinstall LF caliper
7. RF caliper - lower bleeder
8. LF caliper - lower bleeder
9. Rear caliper - rear bleeder

Any thoughts or advice would be welcome.

Mike

***NOTE In your sequence shown, it appears you've REINSTALLED the left front caliper too soon. You should keep it tilted right up to the point of having to reinstall the left caliper to bleed it.
LF, RF, Tilt, PCV Valve, RF, RFL, then reinstall, LFL, then Rear. Those are my thoughts. .02

 

[Gus1300]

Guess What??? it was the SMC!!!!!! Who knew!!!!!

Any further details as to what was found/how it looked/etc? Or did you determine it was the SMC through replacement only (ie, new one and prob disappeared)?