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

The PDF file in post #1 has been replaced with an updated version - It is essentially the same but I have made some minor changes / additions to the text to clarify a few points, replaced some pictures with clearer ones, added a section on the SMC and included comments on fluids, greases and adhesives.
 
Excellent write up, I just finished replacing seals, pistons, new banjo bolts, washers, etc.....front & rear, ...you mention putting rubber grease on exposed portion of pistons...

ie.."Before tightening everything up With everything loosely assembled, it is necessary to pump the pistons in the caliper out so that they press the brake pads against the disc surface. It will then be necessary to remove the pads and apply rubber grease to the exposed part of the pistons to keep them free from road grime. This means lifting the caliper bracket off the rear axle again. "

are you applying grease to the exposed part of the piston after you put new pads on?, won't that melt or attract road debris?
 
Thank you for the comment @MarkJ .

I put the pads in place without grease on the pistons to start off with. At this point the caliper, bracket and rear axle are just loosely in place. So it is easy to remove the caliper and bracket again.

Then I smear rubber grease to the outside of the pistons, and I smear the insides as well. Then I put the caliper and bracket onto the axle, locate and secure the large caliper stopper bolt, tighten the axle and replace the pads and the pad retaining pin.

Regarding heat. You are right to question this. The operating temperature range is relatively low, Yet Rubber Grease is required to be applied to the dust seal. The key question is - Does it melt? Well for me, the answer is'No'. I checked when I first started to use it, and each time I service the brakes which is at least every tyre change - 5000 miles - I still take a good look. In later years I have become less bothered, and my thin smears have become a bit more liberal, as I apply it blind, on my finger with the pads removed but with the caliper in place. I can see the resulting daub of red grease through the wheel spokes from the other side. They are still there the next time I have the pads out - albeit covered in road grime.

But maybe I am wrong to do this.

Attracting Road Debris ?

Grease doesn't attract debris as such. The entire rear caliper is in a position where grit And grime gets chucked onto it - from all angles. With or without grease, the pistons will become caked in crud. Usually this appears and hardens as the water dries away. And it sticks pretty well to bare metal - particularly with stuff that gets dissolved or suspended in water. Eg Salt, lime, animal waste. Maybe if I lived somewhere else I would do things differently. But I live in the Yorkshire Dales, and if I didn't ride in all weathers, i wouldn't ride at all. It's wet a lot of the time, and sometimes after rain, the car which is parked outside, and the plants have a thin smattering of calcium.

if there is a smear of rubber grease on the pistons, yes - of course the muck sticks to that, rather than to the bare metal, but they always clean up shiny new with just a wipe with a paper towel. There is no concern about muck damaging the seals - the part that has grease on it never goes back into the bore.

I used to use copper grease. That stays put, but if it contacts the dust seal, the seal will swell. Maybe Ceratec would be better ?
 
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jfheath said:
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 and various fluids, lubricants and adhesives related to the braking system.
Click to expand...
Thanks John Great advice. I usually service my brakes every two years. this 2016 PA i just bought is the first one with linked/abs brakes. I will use your article when its time to do it.
 
Both of my tags are sightly angled, is this normal? You can only see one here but they’re both the same.
 

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I've not seen that before, but I think it is probably better than a vertical tag like the ones on my bike. As the pad is pushed up against the spring, this angle would encourage the pad to move to the correct side of the tag.

That is possibly a design amendment. It does the job of making sure the pad is kept in place once they are inserted, and it actually helps to get it right when pads are being installed.
 
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jfheath said:
I've not seen that before, but I think it is probably better than a vertical tag like the ones on my bike. As the pad is pushed up against the spring, this angle would encourage the pad to move to the correct side of the tag.

That is possibly a design amendment. It does the job of making sure the pad is kept in place when they are being inserted, and it actually helps to get it right when pads are installed.
Click to expand...
It's for an '07. As far as I know, the brakes have only been worked on by a Honda dealer and on it's 3rd set of pads. The front two kinda do the same thing, depends on what angle you look at them from.
 
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jfheath said:
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 and various fluids, lubricants and adhesives related to the braking system.
Click to expand...

Hi John,

Don't know if you're still active or not but figured I'd give it a shot. I found your PDF after I changed my rear brake pads. And yes, I pushed the piston in without opening the bleeder. Now the brakes don't release correctly. In your PDF, you state that "and pushing both pistons together will put pressure into the SMC circuit. This can cause problems with the back brake binding later on"

Shop wants to rebuild the caliper. I'm not convinced that is the problem. If the rebuild doesn't fix the issue, it's likely something related to the quote above from your PDF. What would you look for as the potential problem?
08 ST1300
 
Welcome to the forums!

To answer your question. No. that wouldn't cause your brake drag necessarily.

There is nothing fundamentally wrong with pushing in the outer pistons without opening the bleed valve.

But when I saw the phrase that you quoted, I was initially surprised by it. I had to go and find it in the text to see it in context.
Looking at the tone of those two paragraphs, I was trying to warn people away from doing things without thinking of the consequences.

When first working on the brakes, I don't think many people consider what is happening or where the fluid goes.
The circuit to the rear outer pistons is the longest, most complex circuit that exists on the ST1300. There is a lot of resistance to pushing in the rear outer pistons. Eventually, the fluid returns to the rear brake fluid reservoir. If that gets full, there will be problems,

Why would it become full ? Well, it shouldn't, unless someone has topped up the fluid some time after the current set of brake pads were fitted when new. In that case, it will become full.

I didn't want the Avoid the Pitfalls article to be about the SMC - although I added a couple of pages about it. It was more to do with what can go wrong when fitting the calipers and pads.

So rather than explaining everything, and going off into a massive detour, I simply made that statement. It is true, it flags up a warning, but it explains nothing about the hows and whys of potential SMC issues and caliper bracket issues.

The dragging rear brake could be due to many things - many of which are mentioned in the article.
It could be due to :
Mis-aligned caliper bracket - look for spiral fluting in the caliper bracket stopper bolt hole
SMC - not moving and releasing properly
Front left brake dragging slightly due to not following front wheel installation procedure
Front left Caliper pistons not releasing
Slider pins or pad pins on rear or on front left caliper
Crud in the brake lines blocking free movement of fluid.
Pads and pad springs fitted incorrectly.
the list goes on

I would
Test the front brakes first....
Apply front brake lever hard. Spin the front wheel. See if it drags.
Apply the rear brake hard. Spin the front wheel (yes front). See if it drags.
If the front left caliper drags, it will activate the SMC and make the rear calipr drag even harder.
So the front left caliper dragging could be the cause of the rear drag. Eliminate that possibility first.

Do the SMC check. Spin the rear wheel. See how much drag there is.
Apply the SMC by hand. The rear wheel should lock. The SMC should move only 1-2 mm. Push it forward towards the fork leg.
The rear wheel should release when the SMC releases.
If it doesn't then there is likely an issue with the SMC

But it is hard to diagnose the SMC as the cause of the drag if the rear caliper is the cause.

Its an old bike. Mine is one if the last models made - a A9 model built Sep 2013 - and it is still an old bike.
At some point the SMC and the calipers are going to need service / replacement. Mine is 8.5 years old and it has had new seals on all calipers, one new piston and a new (precautionary) SMC.

I would be thinking that I may have to service the rear caliper and maybe replace the SMC at this point.

What you don't want is someone who has never worked with the Honda combined braking and SMC to be doing a trial and error fix.
Have they serviced the bike over the years? I wonder if they flushed out the SMC, tilted it and exercised it when they replaced fluids.

Let me think more about this. It could do with a conversation to find out how confident you are with spanners and fluids.

If he has time, @Igofar may get in touch. If he does get back to him. He will probably send a private message. You're new to the forum so you may need to find out where to look.

So I have just sent one to give you a heads up.
 
jfheath said:
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 and various fluids, lubricants and adhesives related to the braking system.
Click to expand...
Great insight and sharing experience. Thank you!
Gmac
 
Happened across this thread due to rear brake issues on a 2004 non abs st1300.
I’ve recently had the SMC repair kit installed on bike (by ex honda tech ), however rear brake is still binding slightly.
I’ve re-built the rear calliper myself with new pistons and seals, new rubber boots/rubber slider and used silicone grease sparingly as and where required.
end result is still a stiff rear!
however, when initially bleeding the brakes and the outer two pistons were still clamped off - it worked as I imagine it should, release of rear pedal would allow rear wheel to spin freely and easily.
Bleeding of the outer two pistons then brought back the stiff rear. (All on centre stand)
This is just off rear pedal.

I may try bleeding the SMC circuit again, me and vacuum bleeding don’t get on…. I always manage to get air bubbles. Once bled see how it responds.
If still binding, will release the bleed nipple for the twosome and see if it frees up - if it does, then Im assuming the SMC may not be returning correctly? And best bet is new smc assembly?
bike only has 17,000 miles on it for a 2004…. However don't think maintenance was strong point of previous owners.

when I had the SMC piston repair kit installed, I was told that it might not fix it as it’s better just to replace the assembly…. However already had the repair kit at that point in time. The internals weren’t in bad condition tbh.
 
Valleyboy said:
Happened across this thread due to rear brake issues on a 2004 non abs st1300.
I’ve recently had the SMC repair kit installed on bike (by ex honda tech ), however rear brake is still binding slightly.
I’ve re-built the rear calliper myself with new pistons and seals, new rubber boots/rubber slider and used silicone grease sparingly as and where required.
end result is still a stiff rear!
however, when initially bleeding the brakes and the outer two pistons were still clamped off - it worked as I imagine it should, release of rear pedal would allow rear wheel to spin freely and easily.
Bleeding of the outer two pistons then brought back the stiff rear. (All on centre stand)
This is just off rear pedal.

I may try bleeding the SMC circuit again, me and vacuum bleeding don’t get on…. I always manage to get air bubbles. Once bled see how it responds.
If still binding, will release the bleed nipple for the twosome and see if it frees up - if it does, then Im assuming the SMC may not be returning correctly? And best bet is new smc assembly?
bike only has 17,000 miles on it for a 2004…. However don't think maintenance was strong point of previous owners.

when I had the SMC piston repair kit installed, I was told that it might not fix it as it’s better just to replace the assembly…. However already had the repair kit at that point in time. The internals weren’t in bad condition tbh.
Click to expand...

I had the same experience about this time last year after changing the brake fluid in my non-ABC 2006 model. Ended up bleeding the system five times before all the little air bubbles cleared up. There is a specific bleed sequence to be followed, you have the two front calipers, the rear and the elevated bleed port just below the right side of the upper fuel tank, that one requires removal of our right side fairing panels. Make sure you follow the bleed sequence in the manual. It's depicted on this site, just search on 'St1300 brake bleed sequence' on the search function above.
 
@Oldbikefixr said, "and the elevated bleed port just below the right side of the upper fuel tank, that one requires removal of our right side fairing panels."
@Igofar has a way to get to the proportion control valve by only loosening the top fairing and getting his hand and bleeder in there, but my big clumsy hands required me to have full access to it, to avoid a big mess.
But the point is, the PCV must also be bled, if you are to properly bleed these brakes.
I can only imagine many shops overlook or ignore this step.
 
Was it still binding slightly until you got it fully bled?

Oldbikefixr said:
I had the same experience about this time last year after changing the brake fluid in my non-ABC 2006 model. Ended up bleeding the system five times before all the little air bubbles cleared up. There is a specific bleed sequence to be followed, you have the two front calipers, the rear and the elevated bleed port just below the right side of the upper fuel tank, that one requires removal of our right side fairing panels. Make sure you follow the bleed sequence in the manual. It's depicted on this site, just search on 'St1300 brake bleed sequence' on the search function above.
Click to expand...


Just ordered a full SMC assembly, but can keep as future spare if I can get it working as is.
 
Basically, I believe this is my issue:

Binding rear brake (after using pedal) | ST1300-Brakes

Hi, Another rear brake binding problem (on an 06 with ABS). 1. It only occurs when using the brake pedal (even when stationary), not the front brake lever. 2. Slightly opening the rear/outer (right) bleed nipple releases the rear brake. Because of this I am thinking it is not an issue with the...
www.st-owners.com www.st-owners.com

When bleeding, the centre piston behaves correctly - it’s only once the outer pistons are brought into play i do have binding issues.
the repair on that thread was a rebuild of smc - which has already been done on my bike. So once I’ve tried re-bleeding a few times, if any issues still remain new SMC assembly already on way.
Just to check, no adjustment of push rod required? Already pre-set? (Suppose on assembly it’s already assembled so should be correct?)
cheers.
 
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The push rod is set. Providing somebody hasn't taken it apart and it is trapping a bit of grit.

You can check. This measurement was taken on a brand new SMC for the later models - 2008 onwards. The SMC is a slightly different design. I doubt that it would be a different measurement, but you never know.

If operating the SMC by hand, you can lock your back wheel, and when you release the back wheel becomes free, then you are OK.

See here for a measurement.

SMC Info - 2008 Onwards | ST1300-Brakes | ST-Owners.com


Valleyboy said:
When bleeding, the centre piston behaves correctly - it’s only once the outer pistons are brought into play i do have binding issues.
the repair on that thread was a rebuild of smc - which has already been done on my bike. So once I’ve tried re-bleeding a few times, if any issues still remain new SMC assembly already on way.
Click to expand...


I don't know how you know it is not the centre piston but the outers? When the brake pedal is applied in the garage, it operates all three pistons in the rear caliper.
There are ways of establish which pistons are operating / binding - but I guess that you would have said if you had thought of using any of those.

Bottom line is that if you suspect the SMC on an old bike, the outlay is worth more peace of mind than you can imagine. Knowing that your rear wheel isn't going to lock up any time soon.
But there are plenty of other things that could cause the rear wheel to drag. If you have read some of my stuff about brakes, you will already know that after a throrough service, with nothing wrong with the brakes, I went out for a test ride, and the rears were smoking hot. The culprit seemed to be too much grease on the slider pins.

This and many more casues of rear brake drag can be viewed here. Downlaod the pdf.
Article [13] - ST1300 Maintenance - Brakes- Avoiding the Pitfalls | ST1300 Articles | ST-Owners.com

That's homework for tonight !

In the article that you quote in one of your previous posts, there was something else going on from the symptoms that were described regarding the centre piston. Unless there was a typos in there. I've not revisited recently to see what progress has been made.
 
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As an update, spent several hours on Sunday in the drizzle and occasional rain changing over the smc assembly and bleeding the brakes - what a faff!
Also put silicone grease under rubber boot - managed to get some in there without taking boot off.
Used new copper crush washers…. Fowlers parts want £5 per washer! Stuff that!
out of interest, anyone know what material the Honda ones are made of?

Happy to report the back wheel now spins when releasing brakes considerably better than since when I purchased the bike (1 year ago), bike now feels much better off throttle - also easier to wheel around off bike. surprised at how much a difference it has made.

at somepoint in next 6 months I’ll give front calipers a good clean in situ, I’ve re-built the back but to avoid having to bleed brakes again would prefer to clean in place - bit of dirt and grime building up. Bike is 19 years old though

also noticed the drain port on the SMC is only operational when bike is on sidestand. If on centrestand it’s not at correct angle to let any retained water out - so will wash bike on sidestand from now on

Cheers
 
Sadlsor said:
@Oldbikefixr said, "and the elevated bleed port just below the right side of the upper fuel tank, that one requires removal of our right side fairing panels."
@Igofar has a way to get to the proportion control valve by only loosening the top fairing and getting his hand and bleeder in there, but my big clumsy hands required me to have full access to it, to avoid a big mess.
But the point is, the PCV must also be bled, if you are to properly bleed these brakes.
I can only imagine many shops overlook or ignore this step.
Click to expand...

How critical is it to bleed the PCV? What if I just Bleed the front/rear calipers? I'll assume there would be some old fluid left in the system. Just asking. Wouldn't it eventually be evacuated if done a couple of times?
 
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