Excellent! Glad the problem is sorted and thankful for the white courtesy phone.
Being that you're in Central Florida, now you can go out and ride.
2006 ST1300 ABS 46k odo Rear Brake locks up
- Thread starter 1fixitman
- Start date
Being that you're in Central Florida, now you can go out and ride.
Whooshka
Fairly faST old guy
Good deal that your bike is fixed. Igo can be trusted. This is just another example of what PROPERLY bleeding the brakes can do. No short cuts.
Glad you got everything sorted out....you too, were a pleasure to work with. You really sound like you know your way around a spanner 
This thread brings up a good point, I've had several folks contact me at various stages of trying to figure out why their brakes were dragging, and on several of these times, I was told the same thing..."the bore looked clean in my SMC so I put it back together, it must be something else" etc. Folks were too quick to write off the problem being the SMC because it appeared clean.
When in reality (like you found) the rust/crap was trapped in the filter out of view, causing the piston to lock up and not move as it should.
Sometimes it would move, other times not so much.
I am not suggesting that anyone take their SMC apart to clean or inspect it, I'm from the camp of replacing the entire sealed unit for safety reasons, however, folks should know that sometimes the cause can be hidden out of view in plain sight.
A simple way to check to see if the SMC is suspect, would be as I guided you through the function tests.
Does it lock the wheel quickly, or slowly? Can you operate the piston once the PCV is opened to ensure smooth movement etc.
Once you and I determined that the piston was locked up and frozen, I suspected the blockage you found.
Anyhow, great job, I hope you get many happy miles out of your bike.
If you ever need anything, I'm only as far away as the white courtesy phone.
Igofar - Larry
This thread brings up a good point, I've had several folks contact me at various stages of trying to figure out why their brakes were dragging, and on several of these times, I was told the same thing..."the bore looked clean in my SMC so I put it back together, it must be something else" etc. Folks were too quick to write off the problem being the SMC because it appeared clean.
When in reality (like you found) the rust/crap was trapped in the filter out of view, causing the piston to lock up and not move as it should.
Sometimes it would move, other times not so much.
I am not suggesting that anyone take their SMC apart to clean or inspect it, I'm from the camp of replacing the entire sealed unit for safety reasons, however, folks should know that sometimes the cause can be hidden out of view in plain sight.
A simple way to check to see if the SMC is suspect, would be as I guided you through the function tests.
Does it lock the wheel quickly, or slowly? Can you operate the piston once the PCV is opened to ensure smooth movement etc.
Once you and I determined that the piston was locked up and frozen, I suspected the blockage you found.
Anyhow, great job, I hope you get many happy miles out of your bike.
If you ever need anything, I'm only as far away as the white courtesy phone.
Igofar - Larry
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some of us took the word from the first post that he had inspected it and cleaned it and had dismissed it, i did because he knew spanners, even i had to go elsewhere. hade to gauge knowledge on a forum.
Sent from my ONEPLUS A6003 using Tapatalk
Sent from my ONEPLUS A6003 using Tapatalk
This was the point of my reply, a lot of folks inspect stuff by looking at it, if it appears clean and there is no damage to be seen, it must be good, so they move on and keep looking for answers.
As soon as I walked him through a couple inspection tests, it was discovered. I'm sure a lot of folks miss this at one time or another. Our friend did an outstanding job trouble shooting on his own, and was very patient, and never gave up
Find the cause of Failure, Instead of throwing solutions at a Problem
This exact same thing happened to me with a '99 R1100S front brake system. Locked up the front wheel. Had to disassemble and split the calipers to thoroughly clean the galleries. Found a big wad of decomposed brake line crud where the gallery crosses over between the halves when I split the caliper. The large OD black "rubber" OEM brake lines fail at about 15 -20 years on a lot of bikes, usually the front brakes for some reason. DOT4 is not kind to most plastics.
drrod
Site Supporter
This whole episode is a good example of why replacing the whole SMC, rather than rebuilding, is a good idea. The whole assembly is not as expensive as you might think. Replacing the whole unit just removes a whole lot of variables that may be the issue.
On a slightly different, but related, note.......why is it that bike brake systems need to be flushed and fluid changed so often, as compared to cars? Admittedly, my cages have not had the brake fluid changed out in all the time that I have owned them and the brakes function just fine. A friend has a hydrometer for measuring moisture in brake fluid. I think I am going to borrow it and test the fluid in my cages. May be interesting.
On a slightly different, but related, note.......why is it that bike brake systems need to be flushed and fluid changed so often, as compared to cars? Admittedly, my cages have not had the brake fluid changed out in all the time that I have owned them and the brakes function just fine. A friend has a hydrometer for measuring moisture in brake fluid. I think I am going to borrow it and test the fluid in my cages. May be interesting.
I found that after I installed my new SMC you need to work the piston back and forth when bleeding from now on. That piston needs to be able to slide easily back and forth. I never did that because the service manual does not tell you to do it, it only states to elevate to 15 degrees.
On future brake bleeds use the piston of the SMC to help get the fluid through it.
Just my .02
This is very common on BMW's for some reason. I have seen several BMW's that were purchased new, serviced regularly, and still the brake lines crumbled and clogged up the systems.
This is why most motorcycle service manuals direct you to replace the rubber lines every 4 years, which most folks don't do.
Have you heard of this on the ST also? That is one thing I have never done is replace the hoses....
This sounds like you may still have air in the system. You should not NEED to manually move the piston to flush the system out completely, sometimes it does help, but it should not be needed in most cases.
As far as elevating the SMC to 15 degrees, this also confuses a lot of folks. The SMC needs to be firmly seated on something (milk crate, stand, prop, etc.) and NOT suspended or hanging while doing the service. Most folks don't understand the 15 degree angle, and its easier to explain to them to look at the back of the bracket where the hose exits the unit, this must be at the 12 o-clock position for the air to bleed out. Also, while bleeding this caliper, don't be afraid to move it further in each direction, as well as tapping it to release ALL of the trapped air in the area.
Larry,
I don't have air in the system, this is just a practice I started doing on my own after the last SMC failure. It is not because I have air in the system but want to keep the piston moving freely.
If I get where the piston will not move freely - I will know something is up with the SMC and will need to look further.
I had a Honda Shadow come through last year that had been sitting in the garage for a couple years....Have you heard of this on the ST also? That is one thing I have never done is replace the hoses....
The owner complained that it kept jumping out of gear while riding, while trying to shift.
The clutch master cylinder had green moss growing inside it! After removing (scraping it out) we could not force fluid down the lines...
The slave cylinder was completely packed with green moss as well! After cleaning that out, we still couldn't for fluid down the lines...
The lines were cut open with a razor blade and found to be completely packed with, you guessed it, green moss
.The brake lines were all crumbling inside as well.
I have not seen many ST1300's with degraded lines on them, probably due to having to flush the system out often due to brake dragging issues, however, I have seen more than my share of melted rear lines from heat, and split and torn lines on the handlebars from using one or more set of risers, being routed incorrectly, pinched, or having zip ties clamped down on them.
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He'll you sound like you know I have an 03 my back tire locked up I loosen the caliper to free back wheel and it locked up again and first gear is doing OK but when I go into the others it's not doing anythingGo get yourself some Hot tea or coffee John....he has an 06 ST1300
Now think about what you just wrote..."only when you activated the front brake lever"...remember when you press the foot pedal, it activates the center piston on the left front caliper, and when it grabs....you guessed it, it activates the SMC etc.
Thanks for all help and suggestions that ya'll are providing to our member in need
I agree, that it may be the SMC, however, he stated that he only activated the rear pedal to move the pistons when it locked back up, the SMC would not have been activated unless the bike was in motion.
I'm thinking bent clip tabs, suction on the guide dowels, or a bent rear caliper bracket, among other things....
Don't fret fixitman, you'll have plenty of assistance from all these kind folks, we'll crack this nut and get your bike sorted for ya.
Just thinking outside the box here...I've been known to do that once in a while...when we talked, you said you could hardly turn your rear wheel?
Did you do the function test, and if so, what happened? Did it release the rear wheel?
Call me tomorrow before you dive into the bike again, as I have a few more questions.
Before you start tearing the rear wheel apart, and removing it from the bike, pull the hanger pin, grasp the ends of both pads with your thumb and index finger, and while squeezing the pads against the rotor, turn the wheel backwards, this will simply allow both the pads to ride out with ease.
Once the pads for out of the caliper, and while the housing is still attached via the 14 mm head stopper bolt, and the axle, try and turn the wheel now.
It should be completely free to spin, and you should get several rotations with one brisk spin.
If not....I'm wondering if your bike has a couple different things going on at the same time.
I'm curious if your flange bearings are toast?
One more thing to rule out.
Talk to you tomorrow.
Larry
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He is indisposed currently.
what's not doing anything. If it's the rear brake locking up, open the rear caliper bleeder and the brake frees up you have a hydraulic problem
ToddC
Site Supporter
Read the brake section on this forum...
Unless it’s an alignment issue, and releasing pressure just allows it to settle and realign,
How do I manipulate the smc while turning the back tire