Braking problem

[magnaryder02]

I noticed the other day when I was going up the side of the mountain that the bike seemed to be lacking power. It was about a 2 mile ascent and when I got to the top where there is a stop sign I pulled in the clutch and the bike almost immediately came to a stop all by itself. Reading about the SMC before I tapped the back brake pedal and it didn't seem to do anything. So I just gave it a little extra throttle and pushed on. I think after a few hundred feet it let go and everything was back to normal and it gave me no more problems. The bike is an 06 ST1300 with a little under 15k miles. Does this sound like an SMC issue or was it just a fluke?

 

[wjbertrand]

I wonder if a pebble or something got caught in the left caliper causing it to bind?

 

[Mellow]

Has your brake fluid ever beech changed?

It's a low mileage bike in an area that does see some inclement weather so it's possible there's some type of corrosion on the SMC and it's starting to stick.

If you have someone that can help you, you can put the bike on the centerstand and spin the rear wheel then push up on the left caliper and it should activate the rear brake to stop the wheel... it should then release enough so you can spin the wheel again.. if the rear wheel seems locked then it could be an SMC issue.

Could also be as Jeff mentioned, pebbles get caught in calipers all the time but will vibrate loose.

 

[Igofar]

Has your brake fluid ever beech changed?

It's a low mileage bike in an area that does see some inclement weather so it's possible there's some type of corrosion on the SMC and it's starting to stick.

If you have someone that can help you, you can put the bike on the centerstand and spin the rear wheel then push up on the left caliper and it should activate the rear brake to stop the wheel... it should then release enough so you can spin the wheel again.. if the rear wheel seems locked then it could be an SMC issue.

Could also be as Jeff mentioned, pebbles get caught in calipers all the time but will vibrate loose.

Good Advice. The second part of checking the SMC for function, is to have someone push down the rear of the bike (or use a jack) and have someone spin the front wheel while its in the air, then apply the foot brake.
The front tire should stop, and then just as the rear, when you release the foot lever, the front wheel should spin freely again. If it does not, it could be one of the front calipers is sticking and activating the SMC, causing the rear wheel to drag.
Please be carefull riding it until you find the cause, as the SMC can cause the rear wheel to lock up anytime, at any speed when they fail.
Ride safe

 

[magnaryder02]

An update, I tried leaving today and when I was pushing the bike out it I could feel resistance so I hit the back brake and it wouldn't let go so I had to put it in gear to push it 2 feet forward.

 

[magnaryder02]

I went out and put it on the center stand and the back wheel wouldn't move. I tapped the SMC with a hammer and it sort of let loose. I can get about 1/2 turn out of the back wheel when I try and spin it. Does this sound like I should just replace the SMC. I have never flushed the brake fluid, but it is still clear in the sight glass.

 

[Mellow]

I went out and put it on the center stand and the back wheel wouldn't move. I tapped the SMC with a hammer and it sort of let loose. I can get about 1/2 turn out of the back wheel when I try and spin it. Does this sound like I should just replace the SMC. I have never flushed the brake fluid, but it is still clear in the sight glass.

The sight glass is deceptive. I've see clear ones but 'stuff' in the fluid when you opened up the reservoir.

I would try flushing the fluid first as that's the cheapest 1st option... then, if that doesn't work, probably gonna need an smc rebuild kit or whole assembly which is easier and just a little more $$.

 

[magnaryder02]

Ok I will try replacing the brake fluid first, where is the cheapest place to buy a new smc or rebuild kits?

 

[Mellow]

Ok I will try replacing the brake fluid first, where is the cheapest place to buy a new smc or rebuild kits?

check ronayres.com, bikerbandit, cheapcycleparts.com and I'm sure some will suggest others. But the differences will typically be small between them. Be sure to only order the one for your year model bike as in 2008 they changed and you cannot substitue the 2008 and newer ones from what I'm seeing - but I could be wrong there.

 

[magnaryder02]

So I greased the pivot bearing which was suggested by Igofar and bled the brakes with a great write up and a phone call with him and now I am leaving pressure over night. I also went ahead and bled the clutch while I was at it and it needed it! I'll find out tomorrow if this works.

 

[scooterdoc]

Ok I will try replacing the brake fluid first, where is the cheapest place to buy a new smc or rebuild kits?

babbittsonline.com have good prices as well. either way, rebuild or replace is pretty easy. just follow the guidance given.

 

[Igofar]

So I greased the pivot bearing which was suggested by Igofar and bled the brakes with a great write up and a phone call with him and now I am leaving pressure over night. I also went ahead and bled the clutch while I was at it and it needed it! I'll find out tomorrow if this works.

Did you happen to clean the calipers and the pistons while you where bleeding your system, or simply do the bleed procedure?
We're hoping to hear good news tonight.
If you still have issues, I would suggest looking into the SMC next.
Good luck.

 

[scooterdoc]

The sight glass is deceptive. I've see clear ones but 'stuff' in the fluid when you opened up the reservoir.

Just because there is clear fluid in the window does not mean there is adequate fluid in the reservoir.

Just a thought.

 

[magnaryder02]

Well I took it for a brief ride Tuesday and it did ok, but it rained the next couple of days. I'll be taking it to work tonight so hopefully everything is good.

 

[magnaryder02]

Did you happen to clean the calipers and the pistons while you where bleeding your system, or simply do the bleed procedure?
We're hoping to hear good news tonight.
If you still have issues, I would suggest looking into the SMC next.
Good luck.

I didn't, I just flushed out the lines.

 

[magnaryder02]

Well after 28 miles I didn't have any issues so hopefully all is well!