Hello, I live in Anchorage, Alaska and I have a 2007 ST1300A with ABS, that I bought brand new. I have never had any problems what so ever with the brakes. This spring (March), I took the forks off to replace leaking fork seals. After replacing the seals, I put the forks back on my bike. It was late at night when I almost finished, I just had a few things to tighten up, 0one of which were the front axle and axle pinch bolts. Thinking that I would get right back to the job first thing in the morning, I had to do a few other things first and promptly forgot about the loose bolts. Approximately two to three weeks later, the weather cleared up and I decided to ride my bike to my shop. As I drove out of my garage, I noticed that the ABS indicator light was flashing, which is always does until it calibrates itself and I didn't think anything about it. After driving approximately 150 yards, I noticed that the ABS indicator was still flashing, thinking that I may have an issue with my braking system, I tried to check to see if the ABS was working by stepping on the rear brake to see if it would go into ABS or lock up. The rear locked up briefly and I continued on my way to my shop. I drove approximately 1 mile, where I had to stop for a traffic light. As I pulled in the clutch, the bike suddenly came to a controlled stop approximately 2-3 vehicle lengths behind the vehicle in front of me. At this point, I remembered that the pinch bolts were loose. I was approximately halfway between my house and shop, where most of my tools were located, so I decided to continue to my shop and fix the brake system. As I was driving, at a very low speed, I thought that the front wheel was trying to lock up due to the loose pinch bolts. I drove to my shop, all the time I could feel the brake working against the engine. When I pulled into the driveway to my shop, the rear wheel locked up on the gravel and I could not move the bike. I managed to get the bike into the shop by loosening the rear brake bleed nipple (the center system bleed nipple). When I cracked the nipple open, the boiling brake fluid shot out and the rear wheel released. I have tried to get my bike functioning again, without any success. I initially replaced all the rear brake hoses, thinking that one of them was bad, didn't fix anything. I then replaced the proportional valve, didn't work. I replaced the rear ABS Modulator (holy crap that was expensive!!!!) .... didn't fix the problem, I replaced the rear caliper, didn't fix the problem. I am at wits end. I have gone through about a gallon of Motul 5.1 Brake fluid and a quart of EBC 4.1 brake fluid. I basically replaced the entire rear braking system with the exception of the rear brake master cylinder, I did take it apart and checked it, it looked normal. Any body out there have any idea on how to fix my ABS brakes? I am about to take off all the rear ABS.
I need some help with my brakes!!
- Thread starter HRRacing
- Start date
LetErBuck
Brian Oehlert
Do you have the shop manual?
There is great info. on here with a simplified bleeding procedure. Mellow had posted it.
Can you get the brakes to work just sitting on the stand. Grab and release? or do they just lock up?
A bit more information with what it is currently doing would help.
There is great info. on here with a simplified bleeding procedure. Mellow had posted it.
Can you get the brakes to work just sitting on the stand. Grab and release? or do they just lock up?
A bit more information with what it is currently doing would help.
I have the 2.5 Inch thick shop manual and have followed it exactly many times. I took the left front caliper off and angled it 0-15 degrees as the manual directed, I've done everything that you're supposed to do (at least I thought you're supposed to do) to get this bike back on the road. I have been trying and replacing each component for the past three and a half months. My last resort is that I am going to rip out the ABS system in the rear. It's the only thing that I haven't done
The bike is up on it's center stand right now, with the rear wheel is off the ground. I am using a pump up brake bleeder, and when the system is pumped up. the rear peddle is firm, the rear tire will not move. As soon as I release the pressure, either using the center or outside bleed valve, the rear pad loosen and the tire can move. basically, what I have noticed is that the rear brake system will apply but not release the pads when the foot peddle is released.
The absolute first place I would start is with the SMC (secondary master cylinder) located on the front left caliper. If it is stuck in, it will cause the back brake to be applied.
When you apply the front brake, the front left caliper rotates slightly on the pivot point, compressing the plunger on the SMC which applies pressure to the rear brake.
There are many many threads on this here.
Arrow pointing to it says "......moves freely"
When you apply the front brake, the front left caliper rotates slightly on the pivot point, compressing the plunger on the SMC which applies pressure to the rear brake.
There are many many threads on this here.
Arrow pointing to it says "......moves freely"
Last edited:
I will check this first thing in the morning. Thanks!!
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I had to replace my SMC as it was sticking causing pressure on the rear brakes. Good luck.
LetErBuck
Brian Oehlert
YES !! That is it !
Mellow has a "correct brake bleed procedure" on here that mentions "pumping" this when it is removed. I will look for the article and post it here if I can.
Mellow has a "correct brake bleed procedure" on here that mentions "pumping" this when it is removed. I will look for the article and post it here if I can.
LetErBuck
Brian Oehlert
https://www.st-owners.com/forums/showthread.php?53678-ST1300-Brake-Bleeding-Sequence-Cheat-Sheet/page4
Check out post #39
You may want to go thru this post from the beginning. This is how I bled my brakes without issue.
I use a Motion Pro brake bleeder (one way valve) It worked flawlessly and I did it myself.
Hope this will get you on your way !
Check out post #39
You may want to go thru this post from the beginning. This is how I bled my brakes without issue.
I use a Motion Pro brake bleeder (one way valve) It worked flawlessly and I did it myself.
Hope this will get you on your way !
Somewhere on here is the diagram of the brake system.
If you're pushing on the pedal and the wheel locks up the SMC is not in play.
iirc that's the center piston bleed nipple on the rear caliper.
Maybe a blocked orifice on the return of the rear master cylinder?
The SMC only operates while in motion and pressure from the front brake causes the front left caliper body to rotate forward slightly putting pressure on the SMC piston. If that sticks it keeps pressure on the outer two pistons of the back brake. That would need the rear outer piston bleed screw cracked to relieve pressure.
If you're pushing on the pedal and the wheel locks up the SMC is not in play.
iirc that's the center piston bleed nipple on the rear caliper.
Maybe a blocked orifice on the return of the rear master cylinder?
The SMC only operates while in motion and pressure from the front brake causes the front left caliper body to rotate forward slightly putting pressure on the SMC piston. If that sticks it keeps pressure on the outer two pistons of the back brake. That would need the rear outer piston bleed screw cracked to relieve pressure.
I just checked the SMC, That was the problem. I tried to move the left caliper bracket and it would not move and the rear tire did not free up. I took the assembly off the left fork and pulled on the SMC push rod that attaches to the fork and the rear wheel freed up noticeably. There was still some brake being applied, but I believe that it was caused by the SMC still applying pressure to the rear system. I think that as soon as I replace the SMC, this problem will be history. Thanks again for the great help!!!
That's available as a piston kit or the full assy.
If you're using the rebuild kit check the inner bore of the assy for corrosion.
Note; 2008 and later uses a different assy.
If you're using the rebuild kit check the inner bore of the assy for corrosion.
Note; 2008 and later uses a different assy.
I just ordered the whole assembly. I am not going to dick around with it anymore.
I wasn't touching the rear brake pedal at any time during this. it was just locked up. I bled the system using an automatic bleeder from MityVac. The problem was in fact the Secondary Master Cylinder.