ST1300 Front Brakes do not release

[XS Michael]

Hello from Germany!

I am new to your forum and I drive my ST1300 (build in 2002) since many years. I am 62 years old and drove an XS1100 for a long time before I changed to a newer bike. The PAN has 150.000 kilometers now. It's an ABS-model - in Germany, we have only the ABS-Version.

I really need help - even the german St-owners Forum could not help me. So I thought, I go to the american forum to get information. I got a lot of information, but sometimes, I did not really understand the "american english"

So, please forgive me, if I ask something, which was already answered in your forum.

My problem:
Since two years, my Honda dealer tries to find out, why the front brakes (both) do not "give free" after I released the brake. He changed nearly everything. He opened the calipers 3 times and replaced the inside - he overhauled the main brake cylinder 2 times ..... He even changed the ABS-Module, the brake-disks and the hydraulic brake-hoses (do you say so?). Nothing helped - and it is getting worse. The only thing which helps, is to knock on the calipers when they are blocked. A good knock and the brakes are free. A friend of mine with an 2002 Pan 1300 has exactly the same problem - wasted a lot of money and nothing helped. It seems to be a typical problem - although in you forum you mainly talk about the rear brake - isn't it? Today, my bike is at the HONDA-dealer again and he changes one complete caliper .... I forgot to say, that the outside pistons of the front brake are the ones which do not open - the inside ones (from back brake pedal) open good.

Pleeease - could you just tell me, which part of the motorbike is responsible for that behaviour?

That would be a terrific help for me!

Thanks a lot!

Michael

 

[jfheath]

The first thing that I would try doing. With the pads locked on, undo the locknut underneath the brake lever, and then unscrew the pivot bolt.
Take the lever off.

With the brake lever removed, see if that affects whether or not the calipers have released the brakes.

Reason.

It is possible that someone has replaced the master cylinder at the lever end and used a non Honda part. I have come across one which had a push rod that was too long. Not a lot, but enough.

Another possibility is that the tiny hole in the bottom of the reservoir is blocked. Under that silver cover. If it is, taking off the lever will not help. But releasing a little pressure at the upper bleed valve will reveal if fluid pressure is the culprit, or whether the issue is mechanical.

 

[XS Michael]

The first thing that I would try doing. With the pads locked on, undo the locknut underneath the brake lever, and then unscrew the pivot bolt.
Take the lever off.

With the brake lever removed, see if that affects whether or not the calipers have released the brakes.

Reason.

It is possible that someone has replaced the master cylinder at the lever end and used a non Honda part. I have come across one which had a push rod that was too long. Not a lot, but enough.

Another possibility is that the tiny hole in the bottom of the reservoir is blocked. Under that silver cover. If it is, taking off the lever will not help. But releasing a little pressure at the upper bleed valve will reveal if fluid pressure is the culprit, or whether the issue is mechanical.

Hello,
thanks a lot for your answer! I will do what you wrote and report the result. Although nobody changed any parts of the bike since 2006 when I bought it with only 25.000 km ... But I will test it.
Many Thanks!
Michael

 

[Sadlsor]

Welcome in, Michael. I was born near Baumholder, a long time ago.
We'll have someone jump in shortly, who can give a better answer than I can.
I'm sure it's discouraging that the dealer hasn't yet sorted this issue - the brakes are NOT rocket science, and it should not be so difficult to diagnose and repair.
Glad to have you!
Stand by for the real mechanics to weigh in...

 

[XS Michael]

Hello,

thanks for your friendly welcome! I had to google "Baumholder" Ahh - ok - close to Kaiserslautern - American Air Base ...

Yes - it is very discouraging that the Honda-man just changes a lot of things without thinking a lot. So I still do not know, wether the problem comes from a rest-pressure staying in the system. The Honda-man says: "No" - but how does he know - he never measered the pressure. I asked him today wether we could do this but he sayed: "I do not have the equipment to check this"
Should not be sooo difficult, to get this equipment and put it in the system ...

One of the problems is, that the brake gives free at nearly every thing you do - as soon as I touch a part of the brake-system, it opens the brake ... That makes it really difficult to find the problem.

Many greetings to you,

Michael

 

[jfheath]

Sorry - I launched straight into an answer on my phone. It doesn't show me that you are a new member.
So let me put that right - welcome to the site !!

One of the problems is, that the brake gives free at nearly every thing you do - as soon as I touch a part of the brake-system, it opens the brake ... That makes it really difficult to find the problem.

If the caliper releases when you touch it - I think that brake fluid pressure is not the reason.
But - if it is only the outside pistons that get stuck ....... maybe it is what I first thought (post#2).
The outside pistons of the front calipers are operated only by the front brake lever.
The inside piston is only operated by the brake pedal.

If the pad spring is incorrectly located in the roof of the caliper, then it can interfere with the movement of the caliper. And on models up to 2007, it is possible to put that in the wrong way round. This can causes the pad spring to catch on the outside pistons.

This is a photo of the rear caliper, but the pad spring in the front caliper is the same design for your bike. The wide strip of the spring on the left of the photo, should be closest to the pistons - also on the left of the photo. The narrow strip of spring has those little tags (circled) should be on the inside, closest to the wheel. The inside pad sits just to the right (on the photo) of those tags.
If the spring is put in incorrectly, those tags can get bent.
If the spring is the wrong way round, the outside pad (nearest the pistons) can be pushed off the spring. The spring then rests drops off the top of the pads, and the pad cannot move away from the brake disc .
In both cases, it will stop the caliper from moving properly.

This is a photo of the caliper looking itn the roof. The pistons are pushed all of the way in - they are on the left.



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This is a photo of the rear caliper (split in half) showing how the pad spring presses onto the top of the brake pads. This is the inside half of the rear caliper.



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Below:

Another possibility is that the person assembling the caliper and pads has not spotted that the pads are of a different design.

Rear pad on the left of the photo, front pad in the centre. The right image shows the backing plate (the white pad is the heat shield for the rear pads only).
The obvious difference between the front and rear pads is the notch on the rear pad.
(Some non-Honda brake pads have a notch in the front pads as well as in the rear pads.)




--------

Below

The retaining clip is either smooth for the front caliper or it has a ridge that fits into the notch of the rear pad.

But if someone has put the rear retaining clip in the front caliper bracket, the front Honda pads will not have a notch to ride over the ridge in the (wrong) retaining clip.
The pad will get stuck and not release.

Left: Front retaining clip Right : Rear retaining clip - both shown fromt he underside - so the 'ridge' appears as an indentation.




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If you want to know more about the brakes - then this will probably help. It talks mainly about the back brakes, but the front calipers are a very similar design.

(1) Article [13] - ST1300 Maintenance - Brakes- Avoiding the Pitfalls | ST1300 Articles | ST-Owners.com

There is a lot there to investigate. Plenty for you to look at yourself - so that you have a bit more information to talk to your dealer.

How happy are you taking tools to the bike yourself ?

 

[XS Michael]

Wow, thank you a lot - that's an idea I never had ....

To take tools to my bike does not really make me happy - but I do it. There are some motorbikes im my garage ....
As soon as my bike is back, I will check the pad springs and the brake-pads. And I will read the article and I will tell the results in the next days.

Thanks! Michael

 

[SMSW]

I think your dealer is not a good mechanic. If the brakes are sticking on the front discs, it should be easy to remove a caliper, put a block of wood in the pads place, and apply the brakes. If the pistons stick, that means no residual pressure is in the system. If they do not, it means, as @jfheath has said, the problem is with the pads sticking.

Trouble shooting - finding the solution to a problem, is a matter of taking logical steps and eliminating possibilites. Your mechanic is throwing expensive parts at the problem, and not thinking this through.

edit: oops. If the pistons don't stick with the wood block in place, then you have proved that there is no residual pressure in the system and the mechanic properly rebuilt the calipers. It also means the brake fluid is flowing back to the master cylinder reservoir when hand pressure is removed (no passages are clogged). The problem is with the pads. If the pistons do stick with a wood block in there, then something is wrong with the pistons/calipers/rebuilding job.

 

[SMSW]

Another thought. Are there any Pan European owners near you? If so, you might ask someone for help working on your bike. How about starting a RAN list for the Continent? Rider Assistance Network - people who sign up say what help they can provide a stranded rider or a rider in need of help. Go to Riding in the blue band atop this page, click on US RAN List at bottom of pop up menu and look it over....

 

[rwthomas1]

Simple test: Apply brakes so they get stuck, wheel locks up, etc. Crack bleeder at caliper. If the brakes release, you have a hydraulic problem, and it's upstream of the caliper. If the brakes is still stuck with no hydraulic pressure, the problem is mechanical in the caliper or brake shoes themselves.

RT

 

[Igofar]

Simple test: Apply brakes so they get stuck, wheel locks up, etc. Crack bleeder at caliper. If the brakes release, you have a hydraulic problem, and it's upstream of the caliper. If the brakes is still stuck with no hydraulic pressure, the problem is mechanical in the caliper or brake shoes themselves.

RT

I will have to disagree with your theory, with an explanation....
While cracking open the rear most bleeder on the rear caliper, will release pressure, you cannot rely on that "simple test" to verify if it is a hydraulic problem or not.
The reason being, while it could be a hydraulic problem, it could also be an alignment issue, damaged rear caliper bracket, loose or damaged clip, dirty or dry guide dowel pins, damaged or missing o-ring on the pad retaining pin etc.
Lets say the OP follows your instructions, jams the brakes, then cracks the bleeder, then the brakes release etc.
Was it pressure that released them, or did releasing the pressure simply allow any of these things to settle or re-align because of the released Pressure?
Just some of the things that should be checked are as follows:
Complete inspection and function test of the SMC unit (my bet is the SMC is toast)
Inspect/clean both floating guide dowels on all three calipers
Inspect the condition of the pistons (are they scored or scratched from cleaning them with a scotchbrite pad etc.?)
Are the piston seals in correctly (some of the early ones were directional to allow the piston to pull back into a rest position)
Did someone use spray brake cleaner to clean things up which could cause the seals to swell and stick?
Did someone clean behind the seals/pistons with a wooden toothpick?
Were the seals lightly greased with silicone grease, and the pistons with clean brake fluid when they were put back together?
Are the brake pads OEM or aftermarket?
If they are aftermarket, such as EBC pads, the front pads are too thick for the correct fitment on the front of these bikes and can cause things to bind etc.
Has the Brake system been flushed correctly, and completely?
Is the return port clogged up, causing things to build pressure?
Is the rear brake caliper bracket worn to the point that the front clip is loose, tilting ever so slightly, causing the pistons to bind, until you manual release pressure?
This is a typical alignment issue, not a pressure issue, etc.
There are many things to check....

 

[XS Michael]

Good morning (for me it is morning now)

Igofar - thanks a lot. Wish you were here ....

What you describe fits very well to our experience. We open the bleeder and the brake opens too - but that tells us nothing.
You listed a lot of possible reasons - most of them we already worked through. But some of them not. We will check it all. The "SMC - Unit" - is it the brake-cylinder at the left fork which transferres pressure to the back-brake?

Thanks a lot!

Greetings from Germany,

Michael

 

[caldercay]

The "SMC - Unit" - is it the brake-cylinder at the left fork which transferres pressure to the back-brake?

Yes

Article [13] - ST1300 - Brake Maintenance - Photos of dismantled SMC | ST1300 Articles

A faulty SMC, taken apart, sawn lengthways, with labelled photos and a commentary. This SMC had a brand new service kit fitted not long before it failed again. A while ago I posted a query concerning some weird behaviour on a friends braking system. The symptoms were that in spite of getting...

www.st-owners.com

 

[XS Michael]

Thank you. As far as I understand it, a rotten/broken SMC-Unit would not effect the front brakes. Am I wrong? (my back-brake closes and opens good)

 

[Southwest Ranger 217]

Hello from Germany!

I am new to your forum and I drive my ST1300 (build in 2002) since many years. I am 62 years old and drove an XS1100 for a long time before I changed to a newer bike. The PAN has 150.000 kilometers now. It's an ABS-model - in Germany, we have only the ABS-Version.

I really need help - even the german St-owners Forum could not help me. So I thought, I go to the american forum to get information. I got a lot of information, but sometimes, I did not really understand the "american english"

So, please forgive me, if I ask something, which was already answered in your forum.

My problem:
Since two years, my Honda dealer tries to find out, why the front brakes (both) do not "give free" after I released the brake. He changed nearly everything. He opened the calipers 3 times and replaced the inside - he overhauled the main brake cylinder 2 times ..... He even changed the ABS-Module, the brake-disks and the hydraulic brake-hoses (do you say so?). Nothing helped - and it is getting worse. The only thing which helps, is to knock on the calipers when they are blocked. A good knock and the brakes are free. A friend of mine with an 2002 Pan 1300 has exactly the same problem - wasted a lot of money and nothing helped. It seems to be a typical problem - although in you forum you mainly talk about the rear brake - isn't it? Today, my bike is at the HONDA-dealer again and he changes one complete caliper .... I forgot to say, that the outside pistons of the front brake are the ones which do not open - the inside ones (from back brake pedal) open good.

Pleeease - could you just tell me, which part of the motorbike is responsible for that behaviour?

That would be a terrific help for me!

Thanks a lot!

Michael

Igofar Larry is the break guru. I have personally workd with him. Follow his list and you will fix the problem. Good luck and happy riding. Jim

 

[Sadlsor]

<SNIP some good stuff>
Complete inspection and function test of the SMC unit (my bet is the SMC is toast)
<SNIP>

Interesting, as I was wondering about the SMC as well, but by far the majority of SMC / brake issues I've seen here are all about the rear pistons not releasing.
Without combing through all the posts, I think this is the first (at least that I recall) SMC-related problem with the FRONT brake.

 

[XS Michael]

Hmmm ... there was at least one ST1300 Owner with a blocked rear-brake in our forum. And it is not difficult to understand, that a bad SMC can cause this. But - can it block a front brake (both sides) too? I would say: "No" - but I may be wrong ...

 

[Sadlsor]

Hmmm ... there was at least one ST1300 Owner with a blocked rear-brake in our forum. And it is not difficult to understand, that a bad SMC can cause this. But - can it block a front brake (both sides) too? I would say: "No" - but I may be wrong ...

One of the many fine articles, with a wonderful line drawing, shows the brake circuit including the SMC and the flow of fluid through and around the valving.
I'll look for it today.
Meanwhile, I'll throw this in the mix:

LinkedBrakingSystem < ST13 < STWiki

stwiki.notonthe.net

And I'm not finding what I'm looking for, and need to get on to work. Here's more info and background on the SMC itself (even though yours is a 2002, this may be helpful):

SMC Info - 2008 Onwards | ST1300-Brakes

Some close up photos of a brand new SMC for 2008 models and later - including the measurement for the refitting of the plunger bracket. Above: In this photo, the rubber boot is pulled to one side to reveal the retaining circlip and washer. This is brand new, I am surprised that there is not...

www.st-owners.com

 

[rwthomas1]

I will have to disagree with your theory, with an explanation....
While cracking open the rear most bleeder on the rear caliper, will release pressure, you cannot rely on that "simple test" to verify if it is a hydraulic problem or not.
The reason being, while it could be a hydraulic problem, it could also be an alignment issue, damaged rear caliper bracket, loose or damaged clip, dirty or dry guide dowel pins, damaged or missing o-ring on the pad retaining pin etc.
Lets say the OP follows your instructions, jams the brakes, then cracks the bleeder, then the brakes release etc.
Was it pressure that released them, or did releasing the pressure simply allow any of these things to settle or re-align because of the released Pressure?
Just some of the things that should be checked are as follows:
Complete inspection and function test of the SMC unit (my bet is the SMC is toast)
Inspect/clean both floating guide dowels on all three calipers
Inspect the condition of the pistons (are they scored or scratched from cleaning them with a scotchbrite pad etc.?)
Are the piston seals in correctly (some of the early ones were directional to allow the piston to pull back into a rest position)
Did someone use spray brake cleaner to clean things up which could cause the seals to swell and stick?
Did someone clean behind the seals/pistons with a wooden toothpick?
Were the seals lightly greased with silicone grease, and the pistons with clean brake fluid when they were put back together?
Are the brake pads OEM or aftermarket?
If they are aftermarket, such as EBC pads, the front pads are too thick for the correct fitment on the front of these bikes and can cause things to bind etc.
Has the Brake system been flushed correctly, and completely?
Is the return port clogged up, causing things to build pressure?
Is the rear brake caliper bracket worn to the point that the front clip is loose, tilting ever so slightly, causing the pistons to bind, until you manual release pressure?
This is a typical alignment issue, not a pressure issue, etc.
There are many things to check....

I'm sorry Larry, I know you are the guru, but that doesn't make sense to me. By definition, there should be NO pressure on the pads from the caliper without the hydraulic pressure applied. If hydraulic pressure is applied and then released yet the pads remain engaged, and the wheel unable to rotate, the problem is most certainly in the caliper. Could be pistons, seals, slides, pads, misalignment, etc. But it cannot be the SMC, hoses, master, etc. They are no longer connected, there is no hydraulic pressure.

Now you may disagree with that, and I will respectfully agree to disagree and leave it right there.

RT

 

[XS Michael]

Hello RT,
thanks for your postings. But the thing is: Your proposal is so obvious, that we tried this when the problem started. 2 years ago. And the break opened when we did that. But it also opened, when we just knocked the calipers - and it opened, when we moved the hoses and and and .... So - what did it help us?
Greetings from Germany
Michael