Hi Guys, old topic new questions (I think). (1) Is there is a way to test the Proportioning Value? (2) if the ABS light functions normally i.e. comes on en ignition is rotated to on and then goes off at 6 mph is it safe to assume all is well with the ABS module and both modulators. {3) Is there any failure mode involving he ABS system that can cause the rear wheel to lock? I have a 2003 ST1300A about 50K miles, I have had it three years but two have not been able to ride because i cant seem to get rear brake functioning correctly. It always was spongy, I bleed the system according the the 7 step process and I had normal rear peddle pressure and travel for about 2 min's. Figured I just needed to bleed it again so this time I flushed the system, all new fluid, repeated the bleed process. Was better but not perfect for a while then my rear wheel locked up after I had stopped and used the rear brake peddle. Fast forward two years found a guy who only works on Goldwings. Since the brake systems are the same design he agreed to take a look. He ended up just disconnecting and plugging the line that comes into the rear port on the rear caliper. This did free up the rear wheel and you can use the rear brake but you have to pump it several times to build pressure. He concluded that the ABS modulator and the Proportioning Value must be bad because he couldn't get fluid to pass using a vacuum brake bleeding machine. Of course he could not get just the rear brake to bleed and I am not sure he understands the system well enough to understand you have to bleed the whole system From the volumes written on this topic I know that the SMC is generally considered to be the culprit for this failure mode(most of the time). The parts are too expensive to just (change and see) so I wondered how to confirm a bad PCV or ABS module or modulator unit. The PCV value seems pretty simple so I don't know what exactly would fail other than just getting clogged with dirt in the fluid. My SMC seem to work fine but I can check it again. How could I best isolate the issue to the root-cause?
Rear brake issue
- Thread starter HOS
- Start date
First, stop letting that idiot work on your bike.
Second, go to the RAN list AZ and call me tomorrow, I can teach/explain how to inspect/test/check everything there is in your brake system.
And the call on the white courtesy phone is free.
Standing by….
Second, go to the RAN list AZ and call me tomorrow, I can teach/explain how to inspect/test/check everything there is in your brake system.
And the call on the white courtesy phone is free.
Standing by….
- Joined
- Mar 18, 2006
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- Age
- 70
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- Ilkley, W Yorkshire, UK
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- 2013 ST1300 A9
- 2024 Miles
- 000679
1. Do what @Igofar said
2. ABS failure causing lock up ? No.
3. So he solved the rear brake lockup by making sure that the brake would not work ?
I bet he's done that before and no one has ever come back and complained. RIP.
4. Phone Larry.
Some links for future reference. But call Larry / Igofar
www.st-owners.com
2. ABS failure causing lock up ? No.
3. So he solved the rear brake lockup by making sure that the brake would not work ?
I bet he's done that before and no one has ever come back and complained. RIP.
4. Phone Larry.
Some links for future reference. But call Larry / Igofar
Search results for query: ST1300 - Brake Maintenance
Sadlsor
Site Supporter
Admittedly I'm not the seasoned SMC veteran here, but with the rear brake line disconnected, it would be impossible to "test" the PCV.
It's now blocked off, if i understand your post.
All stop!
Larry will help you sort it.
"Only works on Gold Wings..." would have been my first clue.
I'm another thread, we debate "all bikes lead to a Gold Wing"... but all bike are surely NOT a Gold Wing.
It's now blocked off, if i understand your post.
All stop!
Larry will help you sort it.
"Only works on Gold Wings..." would have been my first clue.
I'm another thread, we debate "all bikes lead to a Gold Wing"... but all bike are surely NOT a Gold Wing.
I had a similar experience where, after buying the bike and taking it out a couple of times, third time around my rear wheel locked up while taking bike out of the garage. I just wanted to ride it home because I had it at a friend's house for storage. I was able to unlock the wheel after playing with the rear brake pedal, however I only rode half a mile and the clutch stuck disengaged and I ended up pushing the bike back to my friend's garage and eventually trailered the bike to my garage for repairs.
Turns out the clutch and brake systems were properly filthy and the fluid reservoirs had "mud" on the bottom .. fluid must have been original. The clutch return port was clogged shut which caused the clutch stuck disengaged. The SMC was filthy but the bore condition was okay (corrosion free) after cleaning. I am confident (based on findings during SMC cleaning) that my rear wheel lock was (indeed) caused by the SMC return ports being partially (and becoming intermittently) shut as dirty fluid moved back and forth in there.
Luckily, I do my own work and it didn't cost me much to restore the hydraulics on the bike and get it back on the road.
It seems that, the repair shops with those "MMI Certified" mechanics are doing less and less real diagnostics and their repair strategy is to replace parts and see if it works. Works for them but not for customers. The fact that mechanics only work on certain model/year bikes tells me that they don't really understand how things work but rather apply blindly what they've learned from previous repairs on similar bikes.
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Yes, the shops here also only work on newer bikes and don't really seem to understand anything about this brake system. I may have a similar issue. I did replace all the fluid but cant tell if there was some build up or dirt in the system. May need to just flush it and bleed it again. There was a safety recall on thIs VIN for the PCV but I don't know if I can find out it this bike had it replaced.
First, I just want to say thanks for all the support. I have read your brake bleeding documentary and it is excellent. I don't of course know how often this bike got brake maintenance over the years. Over all it is in good shape but who knows about the fluids. I suspect that I need to take apart the SMC and PVC and see if they appear to be really gummed up. I have hesitated to do this because they look complicated to take apart/rebuild and I need to get the kits first. I had hoped just new fluid and a good bleed would get it done. The three calipers seem to be moving fine. I can do some test after I reinstall the line from the modulator to the rear caliper and see if I can tell which input (middle piston or two outside pistons) are dragging.1. Do what @Igofar said
2. ABS failure causing lock up ? No.
3. So he solved the rear brake lockup by making sure that the brake would not work ?
I bet he's done that before and no one has ever come back and complained. RIP.
4. Phone Larry.
Some links for future reference. But call Larry / Igofar
Search results for query: ST1300 - Brake Maintenance
I have no Dogs in this fight, but I would Strongly urge you NOT to take apart either of those units.
Trying to rebuild the SMC will just be throwing money away, when you find out that it won't fix the issue.
Seriously, take a couple minutes and call me, and I can talk you through a couple easy tests over the phone, and get you pointed in the right direction.
The call is free.
Trying to rebuild the SMC will just be throwing money away, when you find out that it won't fix the issue.
Seriously, take a couple minutes and call me, and I can talk you through a couple easy tests over the phone, and get you pointed in the right direction.
The call is free.
To your questions... a) I didn't have a problem getting fluid out the PV but, before bleeding I flushed all my brake lines with parts cleaner as system was filthy. A lot of rusty gunk came out. Then I used the vac pump and flushed and bled system via the PV port. Didn't need to pump the SMC. 2) and 3) from your description the ABS system works as intended.
This will need taken apart and cleaned (along with all the calipers) for a system overhaul.
You can test the SMC several ways: a) if bike can roll on its wheels, push the bike for a short distance and apply the front brake to stop the bike. That (using the front brake) will engage the SMC which will engage the rear caliper. Upon front lever release, if the rear brake is still on (rear wheel is locked) then your SMC isn't working; b) with bike stationary, check if there's any axial play in the SMC by lightly pushing the SMC towards the wheel hub, if any play is felt then the SMC piston isn't fully retracting and may cause rear wheel lock; c) if the rear wheel can be turned by hand, engage the SMC by pushing it's body towards the wheel hub and see if rear wheel can be rotated by hand upon releasing the SMC. If the rear wheel locks up then the SMC piston is not fully retracting; d) if the rear wheel is locked up, tap the SMC body with a piece of wood, if rear wheel frees up your SMC is bad.
All these tests are looking to detect if the SMC piston retracts back to home position after being actuated. Should the piston not retract it'll block the fluid return port that releases the pressure to the rear caliper (which is what your mechanic did when he removed the outboard caliper hose)
Thank you. I will call tomorrow.Standing by the
Hi Larry, Sorry, not sure how to call you. What does" RAN List AZ" mean and White Phone". Would really appreciate talking to you.First, stop letting that idiot work on your bike.
Second, go to the RAN list AZ and call me tomorrow, I can teach/explain how to inspect/test/check everything there is in your brake system.
And the call on the white courtesy phone is free.
Standing by….
RAN -> Rider Assistance Network
Not a formal organization, but something many brand enthusiast forums or groups form within their organization to help their members. May go by other names/acronyms elsewhere.
Not a formal organization, but something many brand enthusiast forums or groups form within their organization to help their members. May go by other names/acronyms elsewhere.
Or... you could document a testing procedure that EVERYONE can benefit from.First, stop letting that idiot work on your bike.
Second, go to the RAN list AZ and call me tomorrow, I can teach/explain how to inspect/test/check everything there is in your brake system.
And the call on the white courtesy phone is free.
Standing by….
The only problem I have with that, is interpretation. When I’m dealing with something as serious as brake issues, I want to know folks are doing it correctly, and understand what they are doing. I’ve seen so many folks repeating stuff incorrectly, and thinking what they did is correct, only to have the bike lock up and slide to a stop.
I’ve seen folks demonstrate the “correct” way to test their SMC, by pushing it so hard that they pushed the bike off the center stand! But, because they were able to get the wheel to slow down and stop to some degree, they were sure that it passed the test
I’m retired, and have the time, so if it’s all the same to you, I’ll keep taking to people on the phone if that’s ok.
If you don’t think I’m helping folks, and would like me to stop using my method, I will respect that and stop offering my assistance on the white courtesy phone.
Your forum, your rules, your call.
Don’t want to upset anyone.
I’ve seen folks demonstrate the “correct” way to test their SMC, by pushing it so hard that they pushed the bike off the center stand! But, because they were able to get the wheel to slow down and stop to some degree, they were sure that it passed the test
I’m retired, and have the time, so if it’s all the same to you, I’ll keep taking to people on the phone if that’s ok.
If you don’t think I’m helping folks, and would like me to stop using my method, I will respect that and stop offering my assistance on the white courtesy phone.
Your forum, your rules, your call.
Don’t want to upset anyone.
You help folks which I appreciate. I just wish you would try to document at least some basic things that would reach more than just those that call you. Sorry but I don't believe that the steps can only be interpreted via speech only... or there would be bikes exploding all over the world.
That is all very true, however I for one, would like your input on various issues (how do you test the SMC, how do you tune for less heat, etc.) so I can broaden my bike knowledge (and perhaps correct what I'm doing wrong... which I doubt
) in general and ST knowledge in particular, and surely everyone can benefit from that.All we - forum members that offer others help via posting - can do is describe the repair procedure best we can then it's up to the user to apply the procedure correctly. Then, it'll be some back and forth if the procedure wasn't fully understood nor applied correctly.
But.. that's the beauty of it isn't it...
Cheers!!
Sometimes you just have to talk to folks to make sure they understand…
A few weeks back, a very nice forum member was having issues with his clutch.
I sent him detailed instructions, pictures from the service manual, and spent a lot of time explaining how to do it etc.
I was met with passive resistance, and told he’d been wrenching for years, had his own tools, and had replaced “clutches” before.
After HE read the service manual and instructions, he managed to screw up several things, and the clutch stopped working completely.
Yet he posted his instructions and what he did, followed the service manual (interpretation) which would confuse folks.
What he failed to mention in his posts, was the fact that he didn’t install the clutch plates, judder ring, or offset the outmost disc correctly, and that he used aftermarket springs that were a quarter of an inch to short….a lot of stuff can be missed with posts and comments.
He finally called me, and after a short discussion on the phone, I was able to ask specific questions, and get some pictures, and point out several things that he did wrong and was not aware of that were not described in the manual.
His clutch worked perfectly by the end of the day.
Happy ending.
I’ll try and put together a few tips on inspections and such when I have the time, just right now it’s a bit difficult to sit at a computer and type due to medical issues, and my thumbs are too big for this typing on my phone.
It's sort of like like making a how-to fix your computer document for non computer folks to use..... and we know how that often goes.
Sometimes you just need to do a remote control session / screen sharing meeting and walk them thru it (or do it remotely for them)
Sometimes you just need to do a remote control session / screen sharing meeting and walk them thru it (or do it remotely for them)