Sorry to hear the brake problem continues. Hopefully, your previous mechanic will get it fixed quickly.
ST1300 Front Brakes do not release
- Thread starter XS Michael
- Start date
rwthomas1
Site Supporter
If not for covidmania, a round trip ticket and a couple of beers for Igofar would be cheaper at this point....
Good luck.
RT
Good luck.
RT
??? Igofar, do you live in Germany? If yes - send me your adress!
Sadly, he lives in Arizona (sad for me and other easterners). Seriously, should you ever ship your bike to this side of the puddle and do a long tour of our country, plan to stop by Larry's. He is a professional mechanic and will go over your bike, repair whatever ails it, explaining as he works what he is doing. The education alone is worth the price of admission. More than a few guys have driven west on long trips and scheduled exactly this kind of repair session.??? Igofar, do you live in Germany? If yes - send me your adress!
- Joined
- Mar 18, 2006
- Messages
- 3,161
- Location
- Ilkley, W Yorkshire, UK
- Bike
- 2013 ST1300 A9
- 2025 Miles
- 002293
You are more than welcome to provide him with any of the pdf files that I have written. I know of a few service centres near me that have used them! The link below is just to my articles.
www.st-owners.com
May be relevant to this issue are
ST1300 Articles
May be relevant to this issue are
- Brakes- Avoiding the pitfalls
- Getting all of the air out of the brake system
- Front and rear wheel installation and animation
- Photos of dismantled SMC
Hello,
I did some more testing. I also took off the brake handle as somebody recommended. And I moved the main brake cylinder with my finger. That made no change to the stucked brake.
As far as I can see, it is not the calipers or something inside. And it is not the main brake cylinder. And the brake-hoses are new. So, what is between the main brake cylinder and the calipers? There is one thing called "delay valve". It was changed in 2004 ... Does anybody know what it delays? What happens if it is dirty?
Greetings, Michael
I did some more testing. I also took off the brake handle as somebody recommended. And I moved the main brake cylinder with my finger. That made no change to the stucked brake.
As far as I can see, it is not the calipers or something inside. And it is not the main brake cylinder. And the brake-hoses are new. So, what is between the main brake cylinder and the calipers? There is one thing called "delay valve". It was changed in 2004 ... Does anybody know what it delays? What happens if it is dirty?
Greetings, Michael
Let me see If I can explain it differently, so maybe you'll be able to understand my thoughts....
When you have the OP apply pressure to lock things up, it does just that right? Applying the pressure may be allowing things like pistons, seals, slides, pads, clips, brackets, etc. to lock things up due to miss alignment etc. Now just because you crack the bleeder open, does not mean that you would be able to un-jam things (think crooked and wedged) Sometimes, when the pressure is released, if things are loose enough, it allows things to settle, or re-align themselves etc. However, most times with the brake calipers, stuck is stuck, and your pressure test may not identify the problem correctly.
Think of a clutch slave cylinder for example, if you've ever held one in your hands, and inserted the piston in the housing bore, it will glide in and out easily, but if you take just your fingertips and try and pull it out by just holding onto one side of it, it locks up tight as a drum, and you will not be able to move it at all. This shows you how minor the misalignment can be, and still cause issues.
Hope this helps.
- Joined
- Mar 18, 2006
- Messages
- 3,161
- Location
- Ilkley, W Yorkshire, UK
- Bike
- 2013 ST1300 A9
- 2025 Miles
- 002293
The delay valve acts on the front right centre piston. It 'delays' the application of that piston (and only that piston) until pressure from the brake pedal is sufficient to overcome a spring inside the delay valve. It is not a time delay, and it does not affect the left front centre piston. Nor does it delay the release of the pistons when the pedal is released. It is intended to prevent application of the rear brake pedal in slow speed manoeuvres from making the front end compress, by limiting the brake pedal to applying only the left hand front brake caliper (centre piston) when the pedal is pressed gently - yet applying both if more pressure is applied.
You were quite clear that the centre pistons are not preventing the brakes from releasing - feeler gauges - so this is likely not the cause of your problems.
From what you say, I think your best course of action is to look at how freely the calipers are able to move.
If you havent seen this animation, then it may reveal how the calipers move when the brakes are applied. And if they cannot move like this, then the brakes cannot release. Slider pins x2, brake pad pin, wear and alignment of parts, pad springs, proper wheel fitting .... all play their part.
This is drwan to represent the rear brake caliper, viewed from the back. But the same idea applies to the front.
See @Igofar 's post just above this one too.
Article - Brake Caliper Action | Articles | ST-Owners.com
rwthomas1
Site Supporter
Given the symptoms the OP is experiencing, stuck is stuck. I understand the subtlety you are explaining, that the pressure COMBINED with misalignment would be difficult to diagnose with my method. And I would agree. However in this case where the brakes are locking and staying locked, crack the line at the master if you are concerned about touching the caliper. If it doesn't release, there is a mechanical issue.
RT
Hello,
just to inform about my plans: I will visit a Honda-specialist middle of June together with a colleague who has exactly the same problems as I. He owns a 2002 - Pan 1300 with 150.000 kilometers like I do. We will spend some hours there and we hope, the specialist will find out the reason. He is a lot more systematic than my honda-mechanic - so I am optimistic. I will report the results here.
Thanks a lot and greetings from Germany!
Michael
just to inform about my plans: I will visit a Honda-specialist middle of June together with a colleague who has exactly the same problems as I. He owns a 2002 - Pan 1300 with 150.000 kilometers like I do. We will spend some hours there and we hope, the specialist will find out the reason. He is a lot more systematic than my honda-mechanic - so I am optimistic. I will report the results here.
Thanks a lot and greetings from Germany!
Michael
Here are the news. It is a bit complicated
First: All I wrote about my front-brake is still true. But: The total blocking of the brake does (in my case) not come from the front but from the rear-brake. I did not see that, because my mechanic always talked about the frontbrake (which really does not open good). And when the blocking happend, I did not see that its the backwheel blocked because I have a Wilbers-"Nivomat"-suspension which is a bit longer than the original one, so both wheels touch the street when the bike is on the middle-stand. So, the "heavy blocking" comes from the rear brake - and as we tested (by opening the hydraulic hoses at different spots), it seems to be the secondary cylinder at the left fork which does not "give free". So we will repair this one a second time ...
The Honda-specialist said, that the front-brake-opening in my case is "not really good but still acceptable". I will leave it and watch it. In case of my friend whom I talked about, this seems to be not true - his front brake does not open. The Honda-specialist said to him: Check the main-cylinder again.
This is an example, how easy it is, to run in a wrong direction - but systematic search can help a bit. It's too bad, that our "Honda-specialist" does not repair any more (he is over 70 years old) - but it was good to see, how systematically he checked the things.
Thanks for your input - and if you come to Germany - visit us.
Michael
First: All I wrote about my front-brake is still true. But: The total blocking of the brake does (in my case) not come from the front but from the rear-brake. I did not see that, because my mechanic always talked about the frontbrake (which really does not open good). And when the blocking happend, I did not see that its the backwheel blocked because I have a Wilbers-"Nivomat"-suspension which is a bit longer than the original one, so both wheels touch the street when the bike is on the middle-stand. So, the "heavy blocking" comes from the rear brake - and as we tested (by opening the hydraulic hoses at different spots), it seems to be the secondary cylinder at the left fork which does not "give free". So we will repair this one a second time ...
The Honda-specialist said, that the front-brake-opening in my case is "not really good but still acceptable". I will leave it and watch it. In case of my friend whom I talked about, this seems to be not true - his front brake does not open. The Honda-specialist said to him: Check the main-cylinder again.
This is an example, how easy it is, to run in a wrong direction - but systematic search can help a bit. It's too bad, that our "Honda-specialist" does not repair any more (he is over 70 years old) - but it was good to see, how systematically he checked the things.
Thanks for your input - and if you come to Germany - visit us.
Michael
Andrew Shadow
Site Supporter
If by repair you mean rebuild it, I suggest that you don't. More often than not it is reported that rebuilding it is not successful.
Replace the whole assembly with a new secondary master cylinder from Honda.
Sadlsor
Site Supporter
Plus, you can order the rebuild kit later, and maybe have a spare, IF the rebuild is successful.
Hmmm.
But then how would you know, until you install it?
Anyhow, I went with the new SMC. May order a rebuild kit, and may not. But the new one is working for sure, so there's that.
Hmmm.
But then how would you know, until you install it?
Anyhow, I went with the new SMC. May order a rebuild kit, and may not. But the new one is working for sure, so there's that.
It actually does come from the front, causing the rear brake to lock up.Here are the news. It is a bit complicated
First: All I wrote about my front-brake is still true. But: The total blocking of the brake does (in my case) not come from the front but from the rear-brake. I did not see that, because my mechanic always talked about the frontbrake (which really does not open good). And when the blocking happend, I did not see that its the backwheel blocked because I have a Wilbers-"Nivomat"-suspension which is a bit longer than the original one, so both wheels touch the street when the bike is on the middle-stand. So, the "heavy blocking" comes from the rear brake - and as we tested (by opening the hydraulic hoses at different spots), it seems to be the secondary cylinder at the left fork which does not "give free". So we will repair this one a second time ...
The Honda-specialist said, that the front-brake-opening in my case is "not really good but still acceptable". I will leave it and watch it. In case of my friend whom I talked about, this seems to be not true - his front brake does not open. The Honda-specialist said to him: Check the main-cylinder again.
This is an example, how easy it is, to run in a wrong direction - but systematic search can help a bit. It's too bad, that our "Honda-specialist" does not repair any more (he is over 70 years old) - but it was good to see, how systematically he checked the things.
Thanks for your input - and if you come to Germany - visit us.
Michael
99% sure that your gonna find your secondary master cylinder is damaged and not working correctly, causing the rear brake to lock up and/or drag.
The fact that your "Honda Specialist would say that its "not really good, but still acceptable" would scare the Bejesus out of me!
You have someone who is old enough that he does not know/understand about the linked braking system and SMC set up.
Its NEVER acceptable for ANY part of the brake system to be not working correctly at all times
You stand a much better chance to correct your brake issues by following Mr. Heaths instructions in his well written article that he was kind enough to attach a link to in a few posts above.
And as Andrew pointed out, I would replace the entire unit as a whole, and not try to rebuild it, as this is money wasted, and will not correct the issue (refer to John's article).
Purchase a complete SMC unit, (4) crush washers, a couple bottles of Dot 4 brake fluid, and get a simple check valve to bleed the system, and I'll bet your issues go away.
Igofar, you misunderstood what he said about: "not really good, but still acceptable". There he spoke about my front-brakes. They do not open as good as I it could be - but he said: "good enough". The "real blocking" is the rear-brake - and yes: it comes from the front: from the secondary brake cylinder (which is at the front )
It is interesting for me, that you say: "Repairing the secondary brake cylinder might be not successful" ..... Hmmm - I will think about this point. Can you tell me why? Is that so much more difficult to do than repairing the main brake cylinder?
Greetings! Michael
)It is interesting for me, that you say: "Repairing the secondary brake cylinder might be not successful" ..... Hmmm - I will think about this point. Can you tell me why? Is that so much more difficult to do than repairing the main brake cylinder?
Greetings! Michael
Sadlsor
Site Supporter
@XS Michael I don't have all the links handy, but you will find several articles and mentions of the pros / cons of attempting to rebuild the SMC.
The short story is, the piston bore - which is NOT included in the kit - may be damaged sufficiently to require a complete new piston, and that is not available as a separate part. It comes only with the NEW SMC.
There also are pitfalls associated with fitting the new rubber boot properly, which comes in the kit. It's all documented, and the linked article(-s) by John Heath are the best go-to's on the subject.
No one is incorrect when they / we say the rebuild kit has a much lower success rate than going with a replacement SMC.
The short story is, the piston bore - which is NOT included in the kit - may be damaged sufficiently to require a complete new piston, and that is not available as a separate part. It comes only with the NEW SMC.
There also are pitfalls associated with fitting the new rubber boot properly, which comes in the kit. It's all documented, and the linked article(-s) by John Heath are the best go-to's on the subject.
No one is incorrect when they / we say the rebuild kit has a much lower success rate than going with a replacement SMC.
Andrew Shadow
Site Supporter
When you open up the SMC, you will most likely find one of the four following conditions;
1- The bore is probably corroded. This is why it seizes. It may have significant enough corrosion damage that a rebuild would last only a short time before the damaged areas of the bore chew up the new seals and you are back to square one.
2- The bore is worn oval. Nothing that you can do about that, it requires replacement.
3- Both of the above conditions are present.
4- There is no permanent damage and a good cleaning and rebuild will fix it. This is very unlikely based on the collective experience of this forum.
For the difference in price between the rebuild kit and a new SMC assembly, a new SMC is probably the wiser choice in most instances. The time that you will save in labour, the guarantee of success (assuming a defective SMC has been confirmed), and the piece of mind of knowing that your rear wheel is not going to spontaneously lock up without warning, I would suggest is more than worth that difference in money.
1- The bore is probably corroded. This is why it seizes. It may have significant enough corrosion damage that a rebuild would last only a short time before the damaged areas of the bore chew up the new seals and you are back to square one.
2- The bore is worn oval. Nothing that you can do about that, it requires replacement.
3- Both of the above conditions are present.
4- There is no permanent damage and a good cleaning and rebuild will fix it. This is very unlikely based on the collective experience of this forum.
For the difference in price between the rebuild kit and a new SMC assembly, a new SMC is probably the wiser choice in most instances. The time that you will save in labour, the guarantee of success (assuming a defective SMC has been confirmed), and the piece of mind of knowing that your rear wheel is not going to spontaneously lock up without warning, I would suggest is more than worth that difference in money.
A new SMC and 4 crush washers are probably cheaper than your Co-Pay for your medical insurance
As far as #4 in Andrew's list (good list by the way) I'll add that there are several parts within the SMC that are not supported by Honda, and are unavailable.
Things like the plastic filter/screen and/or O-ring on the back side, that is probably going to be damaged upon attempting to remove it to clean this area.
As far as #4 in Andrew's list (good list by the way) I'll add that there are several parts within the SMC that are not supported by Honda, and are unavailable.
Things like the plastic filter/screen and/or O-ring on the back side, that is probably going to be damaged upon attempting to remove it to clean this area.
Thanks a lot for all the information! I decided to follow your: "change the whole thing - advise" - and a lot of thanks to everybody who explained the reason for that. I understand, that you are right. I just ordered the whole secondary brake-cylinder and it will be replaced next Thursday.
Why the front brakes do not open as perfectly as I would like them to open I still do not know. But: One problem after the other. First we do the secondary brake-cylinder - then we will see.
Greetings from Germany to America!
Why the front brakes do not open as perfectly as I would like them to open I still do not know. But: One problem after the other. First we do the secondary brake-cylinder - then we will see.
Greetings from Germany to America!
Andrew Shadow
Site Supporter
After you have replaced the SMC, you will need to bleed the brakes. I suggest that you do a complete brake fluid flush rather than just bleeding the system.
At the same time you can disassemble, clean and inspect the caliper and piston assemblies. After doing so, you can test your brakes to see if the pistons retract properly or not. If they still do not release properly, brake fluid, cleanliness, lubrication and general inspection will have been taken care of.
Below is a link to an article on how to clean the rear brake pistons. The procedure is the same for the front pistons. The only change that I would suggest is that the pistons be cleaned using a piece of string (old shoe lace works well) soaked in brake fluid. After pushing the pistons out a little, wrap the cord around the piston and rotate it back and forth to clean the piston. This method is less messy than using a brush.
ST1300 - Rear Brake Piston Cleaning
At the same time you can disassemble, clean and inspect the caliper and piston assemblies. After doing so, you can test your brakes to see if the pistons retract properly or not. If they still do not release properly, brake fluid, cleanliness, lubrication and general inspection will have been taken care of.
Below is a link to an article on how to clean the rear brake pistons. The procedure is the same for the front pistons. The only change that I would suggest is that the pistons be cleaned using a piece of string (old shoe lace works well) soaked in brake fluid. After pushing the pistons out a little, wrap the cord around the piston and rotate it back and forth to clean the piston. This method is less messy than using a brush.
ST1300 - Rear Brake Piston Cleaning