Front Brakes Issue

[vetinari]

in the frame of the service we changed the brake pads on my honda pan european st1300. it's year 2002.

we changed the rear and also the front. the rear brake disc was also replaced.

the brake discs were replaced on the front wheel, but the brake discs remained. we put on the original nissin brake pads.

and the problem was solved. the front wheel brakes. after driving, the brake discs are still hot. When driving, you can feel the braking. You can also feel the higher consumption.

We then dropped the brakes down in the workshop. they checked the brake caliper. they checked the functionality of the brakes as such.

We found that the old brakes were unevenly worn. but the brake disc is OK, no defects. we also tried the positioning of the brake and the caliper on the replacement disc. we wanted to check the freedom of the brake suspension. and there it is OK. the disc rotates correctly when the brake is released. but when the brake is put on the bike, you can feel the brake pad scrubbing against the brake disc.

has anyone encountered this problem? is it possible that in 20 years of riding (and 100 000 km of mileage) something like the geometry could have changed? is the solution simply to drive certain kilometres and the brake pads will fit?

thank you for the answer.

 

[Fawlty]

Hi there. I was in Bratislava at the end of September on a Danube river cruise.Great city.
Your brake problem is not unusual and there are some very knowledgeable folks on here that will help you out. Make sure that you follow their instructions closely.
In the meantime, check out this article for some good info. Also do a search for SMC (Secondary Master Cylinder). Good luck.

Article [13] - ST1300 - Brake Maintenance - Getting all the air out of the brake system | ST1300 Articles

A detailed look at the process of getting the air out of the Honda ST1300 brake lines. A sequence of diagrams of the brake circuits, colour coded to show which parts of the system are being accessed when each bleed valve is opened and explanations of where the trouble spots are. These are just...

www.st-owners.com

 

[jfheath]

So you have changed pads all round front and rear.
You have changed brake discs on the front wheel - you say you changed and they remained ???.
You changed the brake disc on the rear wheel.
So the front wheel has been out - if not by you on this occasion, it ahs been out at some point..
Front brake discs are hot.

Ok - that is enough to go on - not much to do with bleeding the brakes required though.

1. Check that the front wheel has been installed correctly - by that I mean do it again from scratch. Your pads were wearing unevenly - so the front wheel is suspect.

Reasons:

• If the front wheel is installed incorrectly then it will be off to one side.
• That puts the brake disc (which are attached to the wheels) out of alignment with the brake calipers (which are attached to the fork legs).
• This causes the brake pads to drag, especially when the pads are new (because there is less space to compensate for errors).
• If the left front brake is dragging, then it will apply the rear brake - due to the secondary master cylinder on the left fork leg being activated.

Here is a link to what to look for.

Article [13] - ST1300 - Maintenance - Front & Rear Wheel Install and Front Axle Animation | ST1300 Articles

Animated sequence to show the correct procedure when installing the front wheel into the forks of a Honda ST1300. The right hand side of the bike is the side with the brake lever. Left is the clutch lever side. This is the convention used in the Honda manuals. The video and the photo below...

www.st-owners.com

2. You have taken the pads out. You need to check that they have been inserted correctly. On the 2002 model up to 2007, the front and the rear calipers are a very similar design.

By checking - I mean do them again. The reason for this are:

• You don't mention whether or not you dropped one of the chrome retaining clips on the floor or whether the pad springs fell out of the caliper. Neither do you know whether this has happened before.
• The calipers need to be free to slide towards the wheel and away from it. So the sliding pins need to be clean and lightly greased with silicone or rubber grease.
• The chrome clips front and back are slightly different - and it matters if they are put into the wrong caliper
• The pads need to sit squarely in the retaining clip at the far (invisible) end of the caliper bracket
• The pad spring needs to be inserted the correct way round.
• The pads need to be put in so that they do not knock out the pad spring ....
• .... or get on the wrong side of a tiny tag on the pad spring. If not, the pads will be out of line. The fact that you say the pads were worn unevenly may suggest that this is already happening.
• If the uneven wear is that one side is wearing more than the other, it suggests that the calipers cannot move freely.

Here is a link. Most of the illustrations and explanations apply to the rear caliper - but the front caliper are almost identical when it comes to how they operate.

Article [13] - ST1300 - Brake Maintenance - Avoiding the Pitfalls | ST1300 Articles

A close hands-on look at the Honda ST1300 braking system. These are personal observations about the things that can go wrong, why they go wrong and what can be done to keep things working sweetly. Updated April 2020 and to address more recent observations, to include information about the SMC...

www.st-owners.com

3. You dont say whether you used Honda pads or you bought cheaper alternatives (eg EBC). EBC have been known to cause issues.

4. Check the rear wheel installation. By that I mean undo the axle bolt and the stopper bolt. (You may want to take the caliper bracket out and look at how the caliper and the caliper bracket slide together). See the above link in para #2 for what to look for.

When secure the wheel make sure that you tighten the caliper bracket stopper bolt FIRST (slides into a hole on the top of the swinging arm), then tighten the axle. Do not, under any circumstances, undo the bolt that secures the sliding pins.

There is a lot to read and understand there. There may be other things going on.
Doubtless you will get comments about the SMC - but for now, ignore them.

Your front brakes are hot, so the front pads are dragging. That will cause the rear brake to be applied. Whether or not there is an issue with the SMC, we cannot tell until the front wheel rotates without any drag.

(Note that with new pads there is likely to be a slight Sssshhhhh ing noise, but nothing that will cause the pads to get hot.)

 

[vetinari]

So you have changed pads all round front and rear.
You have changed brake discs on the front wheel - you say you changed and they remained ???.
You changed the brake disc on the rear wheel.
So the front wheel has been out - if not by you on this occasion, it ahs been out at some point..
Front brake discs are hot.

Ok - that is enough to go on - not much to do with bleeding the brakes required though.

1. Check that the front wheel has been installed correctly - by that I mean do it again from scratch. Your pads were wearing unevenly - so the front wheel is suspect.

Reasons:

• If the front wheel is installed incorrectly then it will be off to one side.
• That puts the brake disc (which are attached to the wheels) out of alignment with the brake calipers (which are attached to the fork legs).
• This causes the brake pads to drag, especially when the pads are new (because there is less space to compensate for errors).
• If the left front brake is dragging, then it will apply the rear brake - due to the secondary master cylinder on the left fork leg being activated.

Here is a link to what to look for.

Article [13] - ST1300 - Maintenance - Front & Rear Wheel Install and Front Axle Animation | ST1300 Articles

Animated sequence to show the correct procedure when installing the front wheel into the forks of a Honda ST1300. The right hand side of the bike is the side with the brake lever. Left is the clutch lever side. This is the convention used in the Honda manuals. The video and the photo below...

www.st-owners.com

2. You have taken the pads out. You need to check that they have been inserted correctly. On the 2002 model up to 2007, the front and the rear calipers are a very similar design.

By checking - I mean do them again. The reason for this are:

• You don't mention whether or not you dropped one of the chrome retaining clips on the floor or whether the pad springs fell out of the caliper. Neither do you know whether this has happened before.
• The calipers need to be free to slide towards the wheel and away from it. So the sliding pins need to be clean and lightly greased with silicone or rubber grease.
• The chrome clips front and back are slightly different - and it matters if they are put into the wrong caliper
• The pads need to sit squarely in the retaining clip at the far (invisible) end of the caliper bracket
• The pad spring needs to be inserted the correct way round.
• The pads need to be put in so that they do not knock out the pad spring ....
• .... or get on the wrong side of a tiny tag on the pad spring. If not, the pads will be out of line. The fact that you say the pads were worn unevenly may suggest that this is already happening.
• If the uneven wear is that one side is wearing more than the other, it suggests that the calipers cannot move freely.

Here is a link. Most of the illustrations and explanations apply to the rear caliper - but the front caliper are almost identical when it comes to how they operate.

Article [13] - ST1300 - Brake Maintenance - Avoiding the Pitfalls | ST1300 Articles

A close hands-on look at the Honda ST1300 braking system. These are personal observations about the things that can go wrong, why they go wrong and what can be done to keep things working sweetly. Updated April 2020 and to address more recent observations, to include information about the SMC...

www.st-owners.com

3. You dont say whether you used Honda pads or you bought cheaper alternatives (eg EBC). EBC have been known to cause issues.

4. Check the rear wheel installation. By that I mean undo the axle bolt and the stopper bolt. (You may want to take the caliper bracket out and look at how the caliper and the caliper bracket slide together). See the above link in para #2 for what to look for.

When secure the wheel make sure that you tighten the caliper bracket stopper bolt FIRST (slides into a hole on the top of the swinging arm), then tighten the axle. Do not, under any circumstances, undo the bolt that secures the sliding pins.

There is a lot to read and understand there. There may be other things going on.
Doubtless you will get comments about the SMC - but for now, ignore them.

Your front brakes are hot, so the front pads are dragging. That will cause the rear brake to be applied. Whether or not there is an issue with the SMC, we cannot tell until the front wheel rotates without any drag.

(Note that with new pads there is likely to be a slight Sssshhhhh ing noise, but nothing that will cause the pads to get hot.)

Thank you ver very much. I'm going to show it to my serviceman.

 

[vetinari]

So you have changed pads all round front and rear.
You have changed brake discs on the front wheel - you say you changed and they remained ???.
You changed the brake disc on the rear wheel.
So the front wheel has been out - if not by you on this occasion, it ahs been out at some point..
Front brake discs are hot.

Ok - that is enough to go on - not much to do with bleeding the brakes required though.

1. Check that the front wheel has been installed correctly - by that I mean do it again from scratch. Your pads were wearing unevenly - so the front wheel is suspect.

Reasons:

• If the front wheel is installed incorrectly then it will be off to one side.
• That puts the brake disc (which are attached to the wheels) out of alignment with the brake calipers (which are attached to the fork legs).
• This causes the brake pads to drag, especially when the pads are new (because there is less space to compensate for errors).
• If the left front brake is dragging, then it will apply the rear brake - due to the secondary master cylinder on the left fork leg being activated.

Here is a link to what to look for.

Article [13] - ST1300 - Maintenance - Front & Rear Wheel Install and Front Axle Animation | ST1300 Articles

Animated sequence to show the correct procedure when installing the front wheel into the forks of a Honda ST1300. The right hand side of the bike is the side with the brake lever. Left is the clutch lever side. This is the convention used in the Honda manuals. The video and the photo below...

www.st-owners.com

2. You have taken the pads out. You need to check that they have been inserted correctly. On the 2002 model up to 2007, the front and the rear calipers are a very similar design.

By checking - I mean do them again. The reason for this are:

• You don't mention whether or not you dropped one of the chrome retaining clips on the floor or whether the pad springs fell out of the caliper. Neither do you know whether this has happened before.
• The calipers need to be free to slide towards the wheel and away from it. So the sliding pins need to be clean and lightly greased with silicone or rubber grease.
• The chrome clips front and back are slightly different - and it matters if they are put into the wrong caliper
• The pads need to sit squarely in the retaining clip at the far (invisible) end of the caliper bracket
• The pad spring needs to be inserted the correct way round.
• The pads need to be put in so that they do not knock out the pad spring ....
• .... or get on the wrong side of a tiny tag on the pad spring. If not, the pads will be out of line. The fact that you say the pads were worn unevenly may suggest that this is already happening.
• If the uneven wear is that one side is wearing more than the other, it suggests that the calipers cannot move freely.

Here is a link. Most of the illustrations and explanations apply to the rear caliper - but the front caliper are almost identical when it comes to how they operate.

Article [13] - ST1300 - Brake Maintenance - Avoiding the Pitfalls | ST1300 Articles

A close hands-on look at the Honda ST1300 braking system. These are personal observations about the things that can go wrong, why they go wrong and what can be done to keep things working sweetly. Updated April 2020 and to address more recent observations, to include information about the SMC...

www.st-owners.com

3. You dont say whether you used Honda pads or you bought cheaper alternatives (eg EBC). EBC have been known to cause issues.

4. Check the rear wheel installation. By that I mean undo the axle bolt and the stopper bolt. (You may want to take the caliper bracket out and look at how the caliper and the caliper bracket slide together). See the above link in para #2 for what to look for.

When secure the wheel make sure that you tighten the caliper bracket stopper bolt FIRST (slides into a hole on the top of the swinging arm), then tighten the axle. Do not, under any circumstances, undo the bolt that secures the sliding pins.

There is a lot to read and understand there. There may be other things going on.
Doubtless you will get comments about the SMC - but for now, ignore them.

Your front brakes are hot, so the front pads are dragging. That will cause the rear brake to be applied. Whether or not there is an issue with the SMC, we cannot tell until the front wheel rotates without any drag.

(Note that with new pads there is likely to be a slight Sssshhhhh ing noise, but nothing that will cause the pads to get hot.)

Here are some aditional info:
The brake discs on the front wheel remained floating.
The brake disc on the rear wheel has been replaced.
Yes the front wheel was already out.
Yes, the front discs were burning.
On point number 2 : I will go over this with my service technician.
On point number 3 : We have used branded nisin brake pads and also the rear disc.

 

[jfheath]

There is one possibility that I didn't mention. I have never come across it, but it is possible.

That is that the rear pedal, master cylinder, reservoir and compensation port may have an issue that prevents the fluid pressure from escaping when the pedal is released. eg the compensation port is blocked in the rear master cylinder. This would cause issues with all 3 pistons in the rear caliper AND the centre piston in each of the front calipers.

This can be checked by checking the fluid level in the rear reservoir. If it is brim full, fluid cannot escape.
If that has been checked, then push in any of the centre pistons - front or back. They should push in fairly easily by thumb pressure.
If they do push in, then fluid is returning ok to the rearveservoir - so the focus should be on why the front brakes are dragging.

Then when that is sorted, focus on whether the SMC is operating and releasing the rear brake ( outer pistons).

Its entirely possible that the fluid was topped up in both reservoirs half way through the life of the old pads. That would mean that if you simply pushed in the pistons to accommodate the new pads, there would be too much fluid in the system , so there is no way that pressure in the brake lines can escape back to the reservoir.

 

[MidLife]

Here are some aditional info:
The brake discs on the front wheel remained floating.
The brake disc on the rear wheel has been replaced.
Yes the front wheel was already out.
Yes, the front discs were burning.
On point number 2 : I will go over this with my service technician.
On point number 3 : We have used branded nisin brake pads and also the rear disc.

Did they clean the caliper pistons and bores?

 

[MidLife]

There is one possibility that I didn't mention. I have never come across it, but it is possible.

That is that the rear pedal, master cylinder, reservoir and compensation port may have an issue that prevents the fluid pressure from escaping when the pedal is released. eg the compensation port is blocked in the rear master cylinder. This would cause issues with all 3 pistons in the rear caliper AND the centre piston in each of the front calipers.

This can be checked by checking the fluid level in the rear reservoir. If it is brim full, fluid cannot escape.
If that has been checked, then push in any of the centre pistons - front or back. They should push in fairly easily by thumb pressure.
If they do push in, then the focus should be on why the front brakes are dragging - first.

Then when that is sorted, focus on whether the SMC is operating and releasing the rear brake ( outer pistons)

After checking the rear reservoir, he could also make a few runs using the front only and see if it heats up or not.