Today I did the function test by rotating rear wheel with right foot and operating the SMC with right hand. It slows the wheel down but did not stop it. I did take off the rear caliper, insert a few stacks of razor blades between pads and cycle the rear brake pedal and low and behold it still locks up. Have to vent both bleeders to release pressure. I sent Igofar pictures of old SMC piston. He recommended I purchase a new SMC. Parts ordered from Ron Ayers.
2006 ST1300 ABS 46k odo Rear Brake locks up
- Thread starter 1fixitman
- Start date
im lost at why you would order parts without identifying the fault!
it might well be the smc which you serviced., if you did it right i would dismiss it myself .
have you the fairing off and cheched the valve near the tank?
until you do a point by point line check , your just throwing money away.
ill withdraw from further comments. good luck.
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it might well be the smc which you serviced., if you did it right i would dismiss it myself .
have you the fairing off and cheched the valve near the tank?
until you do a point by point line check , your just throwing money away.
ill withdraw from further comments. good luck.
Sent from my ONEPLUS A6003 using Tapatalk
When I release pressure from the rear vent it releases the pressure and the wheel is free to spin. Venting center piston does nothing. Verified today. If I actuate the SMC while the brake is locked up it has no affect on releasing it.
John are you sure you have not been listening into our phone conversations on the white courtesy phone?
We think so much alike lately that is spooky.
Thanks for all the suggestions and help.
Your brother from another mother Larry
Here is the pic of the old SMC piston. Note the shiny spots on the two raised metal bits between the seals. Possibly scratched walls of inside of cylinder and note all the brown.
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ToddC
Site Supporter
All that Florida humidity and rain. How many times had you flushed the fluid before this failure?? Just curious.
ToddC
ToddC
One time many years ago. I have learned you need to do it yearly to minimize component failure. Every two years minimum.
CYYJ
Michael
It's fascinating to look at the picture of the SMC component in post #29 and observe that even though the two rubber seals at the top and bottom of the component appear to be in good condition, there is very clear evidence of corrosion on the part between the seals.
I understand that this area of the part is normally completely filled with brake fluid. If we ever needed visual proof that brake fluid is hygroscopic (it attracts and absorbs water), this picture proves it is.
Michael
I understand that this area of the part is normally completely filled with brake fluid. If we ever needed visual proof that brake fluid is hygroscopic (it attracts and absorbs water), this picture proves it is.
Michael
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If that picture is not sufficient reason to pull the old SMC and use it on your boat as an anchor, I don't know what is. Not sure if that crud is rust or not, but as Larry said, it won't take much to clog tiny ports in the body of the unit. Many years ago, when I was young and poor, I pulled auto brake cylinders apart (slaves), honed them bought new seals and rebuilt them. No matter how careful I was, they always seemed to fail in less time than a new one. I eventually became a born again 'replace the old part' guy. Were you in the middle of Kazakhstan on the way to your wedding a day later, had this problem and a local mechanic wanted to rebuild the SMC using ground up pecan shells and old rags for seals, I would say "Go for it", but here, with time and parts available, no way!
If you want one of these orange tubing cutters...this is a blue one on the slow boat from China on e bay for cheap. 1.19$ shipped. Takes forever to arrive.
The circular plastic thing above is the plastic mesh filter/screen out of my SMC. Slammed full of rust. Did another bleed today with a check valve but this time I could not get any fluid from the Proportioning valve bleeder. Took the SMC apart and the screen was full of rust. That check valve for bleeding brakes is behind the tubing cutter. Blue item beside the fluid bottle. So now I am waiting on my new SMC to arrive. Maybe March 14th to 16th.
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The circular plastic thing above is the plastic mesh filter/screen out of my SMC. Slammed full of rust. Did another bleed today with a check valve but this time I could not get any fluid from the Proportioning valve bleeder. Took the SMC apart and the screen was full of rust. That check valve for bleeding brakes is behind the tubing cutter. Blue item beside the fluid bottle. So now I am waiting on my new SMC to arrive. Maybe March 14th to 16th.
You said "I cleaned and rebuilt the front brakes and SMC with all new stock parts and bled all brakes front and rear following proper order"
so ya didnt, or ya did, niw your doing it again. [emoji2955]
where is the palmface gif
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Oh oh, I hear the white courtesy phone ringing. 
Smallville
Scott
My vote is a faulty rubber line going to the rear caliper.
The rubber lines deteriorate from the inside and a small flap will break loose, acting like a one way valve. This allows fluid to pass to apply the brake and not release.
Classic symptoms and the SMC doesn't come into play unless the front wheel is rotating.
Although from the picture it needed attention anyway.
The rubber lines deteriorate from the inside and a small flap will break loose, acting like a one way valve. This allows fluid to pass to apply the brake and not release.
Classic symptoms and the SMC doesn't come into play unless the front wheel is rotating.
Although from the picture it needed attention anyway.
I bought a rebuild kit. The filter/screen was not a part of that kit. I did not even know that screen was under those two bolts until the white courtesy phone conversation.
The filter screen is not on the parts breakdown. Hummmm.
The filter screen is not on the parts breakdown. Hummmm.
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When the brakes initially melted down on the rear I replaced both of those rear hoses with new ones because one ruptured from all the heat. It is written in the 1st post. I guess there is a possibility that they can be bad right out of the box but the new SMC will hopefully fix everything.
We're good, I've got him on SPEED DIAL on the white courtesy phoneOh oh, I hear the white courtesy phone ringing.
Smallville
Scott
Understood. I believe there are more rubber lines than the one close to the rear caliper. Hopefully the SMC will fix it
The SMC and new crush washers arrived and are installed. All bleed ports are bled down in the proper order and I got bubbles and eventually clear fluid without bubbles at all ports. All fastners torqued to spec. Took the bike for a test drive. The front brakes stop faster than they have ever. The rear brake is not locking up any more. I rode a total of 62 miles yesterday. I did a function test to verify that the SMC stops the rear wheel while spinning with right foot spinning the rear wheel and I push the SMC with my right hand. The wheel immediately stops and then releases. The pictures of the mesh filter I previously posted from inside my old SMC was full of rust and corrosion along with the corrosion on the SMC piston.... That was my real issue. So, if you rebuild your SMC please make sure you take those two screws off, gently pull out the o ring and use compressed air to blow the filter out of the socket and thoroughly clean. That filter can not be purchased separately so be very careful with it.
I want to thank Igofar for his wisdom and encouragement during this process along with all the other input from this forum from all involved. Igofar was great to work with on the phone. He has a lot to say but it is all very useful and detailed. If you live near him and need work on the ST and can not do it yourself then send a call out. Thank you for everything. My bike is back on track and I have a huge smile on my face.
I want to thank Igofar for his wisdom and encouragement during this process along with all the other input from this forum from all involved. Igofar was great to work with on the phone. He has a lot to say but it is all very useful and detailed. If you live near him and need work on the ST and can not do it yourself then send a call out. Thank you for everything. My bike is back on track and I have a huge smile on my face.
That's horrible, glad you're getting into it. All this so you don't have to press two levers at the same time. Makes you wonder.......Here is the pic of the old SMC piston. Note the shiny spots on the two raised metal bits between the seals. Possibly scratched walls of inside of cylinder and note all the brown.
Upt'North.