Brakes sticking

easy rider

easy rider

Joined
Feb 3, 2008
Messages
153
Age
47
Location
North Wales Uk
Bike
2009 STX1300ABS
Hi

Need some advice my brakes have been sticking for a while now garage used kits to rebuild rear master cylinder and secondary master cylinder last year and all was well for a while.
First of all it was my rear brake now its both rear and right front brake. the right disc is badly marked with the brake pads scorching the disc.

Last time the bike was in they bled the brakes and it has been fine for a while then my rear started sticking again so lubed up brake pedal and again fine, now front right brake is sticking again badly and rear is also.

At a loss as what is causing this any ideas? Is it worth replacing rear master cylinder the complete assembly or is it something else.
They removed calliper last time and cleaned and full brake bleed.

Really need some advice as this has been going on for a while and desperate for a solution.

Thanks
 
Notoriously known [potential] problem :

Bad SMC.

Many other posts will follow shortly.
(search in here in the meantime).
 
Few guys have had any success rebuilding the SMC. PM @Igofar and give him your phone number. He will talk you thru it.
 
core-aggie said:
Notoriously known [potential] problem :

Bad SMC.

Many other posts will follow shortly.
(search in here in the meantime).
Click to expand...
yes i am also thinking along those lines which is why last year i bought the rebuild kits to rebuild both rear master cylinder and secondary master cylinder on the left front brake with new springs seals etc however I am beginning to think i should have just bought both new assemblies for rear and secondary master cylinders instead of paying to have them rebuilt. if this does not work my last role of the dice is replace all hoses as they are the original hoses from when i bought my bike back in 2009 so it's also a possibility i guess.

Thanks
 
No need to replace the original hoses, as that is probably not the cause of the issue.
Find a new garage/mechanic ;)
Check John Heath's article on avoiding the pitfalls of the brake system, this will educate you on what's going on with your brakes.
Good luck
 
Igofar said:
No need to replace the original hoses, as that is probably not the cause of the issue.
Find a new garage/mechanic ;)
Check John Heath's article on avoiding the pitfalls of the brake system, this will educate you on what's going on with your brakes.
Good luck
Click to expand...

Exactly that ^^^^^

I doubt SERIOUSLY it's hoses - I'd leave those as is.
 
Ok so i have gently moved the pad's back away from rear disc and front right disc started the bike up and completed hard braking using The front brake lever only and the brakes don't seem to be sticking bike rolls back and forward with ease even after repeated use of front brake.
So If you use the brake pedal it drags at the rear and front right sticks as if brakes are stuck on making it difficult to move the bike so its something to do with the linked system as the pedal is what activates the linked system.
Just trying to look at this logically and work out what is causing the issue so i think i will order both master cylinder assemblies for front left brake and rear pedal and see where we go from here. I have downloaded the pdf on brakes also really good article will see if the garage can take a look at this. I can take most things apart on my bike just never been confident with messing with the brakes. Starting to worry now as i really don't want my brakes locking up on me as its my main transport to work.
 
Get a manual. Or use the online one. The entire process is in there. You might not needs parts at all. ie. things happen, parts get stuck. I'm not saying this is the issue but picture the secondary master sticking. That causes the rear brake to drag and deploys the center piston in the right front caliper. Sounds like your issue.
Here is a visualization of the Honda linked brake system. It's generic, but it looks a lot like what I see in the book. If you watch the video to after the ten second mark you'll see the rear pedal actuating things...https://www.youtube.com/watch?v=mS5rRZkkzBI
Hope this helps.
 
I'd write more but I'm not feeling 100%. I suggest you go to articles atop this page, click on it, then ST1300. Scroll down and read all the articles (often threads) on the brake system, especially John Heath's. Also go to the top right end of the blue band atop this page and enter SMC and then Secondary Master Cylinder in the search box. You need to understand how this system operates, and there was a recent thread very much like yours.

From what you said, It sounds to me like your SMC is ok and the problem is with one of the pistons in the rear caliper that is actuated by the foot pedal. Big assumption on my part, when you said "I started the bike up" I take that to mean you went for a short ride. If this is correct, then the SMC actuated piston in the rear caliper is retracting and not dragging. More than a few guys here have ordered a SMC and put it on their shelf. Honda will not keep making these forever, and rebuilding has not met with much success.
 
Well the last two days of using front brake lever only wheels run free its the best they have ever been rear wheel spins perfectly on centre stand and front wheel is also spinning free so it is only when using the brake pedal that it is causing the issue.
Front right brake would lock on and scorch disc and rear wheel sticks and drags.

So the pedal operates the middle pistons I have a new rear master cylinder and SMC also on order.
I get the throwing parts at the problem is not great however the brake problems have been going on for 12 months on and off so other things have been tried callipers removed cleaned and all parts replaced except pistons as they were fine. Just think when we did master cylinders we should have replaced rear master cylinder and SMC assembly instead of rebuilding that was my mistake. Bikes 15 years old been on the road 52 weeks per year every year non stop in all weathers so it has been to hell and back so parts are probably shot.

Understanding that its now the brake pedal action causing the problems does anyone else have any thoughts

I really appreciate everyones help and i have also been reading through many articles trying to understand it.
The garage think i should de link brakes i personnaly would rather fix it and keep it as it is meant to be.
It's understandable its acting up it is old and parts fail just its just working it out.

Thanks everyone
 
Based on your bike's symptoms I think the likely cause is a blockage in the rear master cylinder. There's a tiny port that allows the fluid pressure to release back to the reservoir when the piston retracts when you let off the brake. If that port is blocked (or the piston is seized), then the pressure can't release, and that would keep pressure on the rear brake and the centre pistons on the front. I would have expected the left front centre piston would also be affected but maybe something in the linked system is allowing that to release pressure.
 
TerryS said:
Based on your bike's symptoms I think the likely cause is a blockage in the rear master cylinder. There's a tiny port that allows the fluid pressure to release back to the reservoir when the piston retracts when you let off the brake. If that port is blocked (or the piston is seized), then the pressure can't release, and that would keep pressure on the rear brake and the centre pistons on the front. I would have expected the left front centre piston would also be affected but maybe something in the linked system is allowing that to release pressure.
Click to expand...
Could this happen when the pads are compressed to change a rear tire?
 
Thanks for your ideas everyone always appreciated! As soon as we get the rear master cylinder replaced and secondary master cylinder also replaced which should be arriving after easter we will see how it is.
I remember last year i had only rear brake drag so after the garage rebuilt rear master cylinder and secondary master cylinder shortly after that it introduced the front right calliper locking which i never had any issues with and rear brake issue again. So it has to be something to do with either one of the master cylinders thinking about it now.
That's why i have ordered full assembly for both no messing as something cannot be right with the rebuilds with the kits.
Its my own fault i was toying with the idea of rebuild kits or full assembly last year and i went for the cheaper option which has more room for error with the rebuild kits not thinking that the actual assembly could be coroded and worn or blocked. We live and learn so for now front brake lever only and we are all good . I will of course keep you updated on how thing progress.
 
"Well the last two days of using front brake lever only"
You do realize that your front lever works both front and back calipers right?
While there are MANY things that will cause issues in your brake system, without actually seeing the bike in person, folks can only guess at what is causing your symptoms.
My Guess would be that your SMC is clogged (on the rear side of it) and the cartridge return port hole is blocked.
This will cause pressure to build up and not be released, causing the brakes to do strange things.
Also keep in mind, that the rear brake pedal moves more fluid than the front lever with each press, so your applying more pressure, thus building up more pressure quicker than just using the front lever.
I'm guessing that when you replace the SMC and bleed the system correctly, you issues will go away.
 
Igofar said:
"Well the last two days of using front brake lever only"
You do realize that your front lever works both front and back calipers right?
While there are MANY things that will cause issues in your brake system, without actually seeing the bike in person, folks can only guess at what is causing your symptoms.
My Guess would be that your SMC is clogged (on the rear side of it) and the cartridge return port hole is blocked.
This will cause pressure to build up and not be released, causing the brakes to do strange things.
Also keep in mind, that the rear brake pedal moves more fluid than the front lever with each press, so your applying more pressure, thus building up more pressure quicker than just using the front lever.
I'm guessing that when you replace the SMC and bleed the system correctly, you issues will go away.
Click to expand...

Yes outer pistons on the front and back callipers using front brake lever and its the centre pistons operated by the rear brake pedal which is what seems to be causing the brake to stick at the back and the front right calliper to actually lock on, So after some investigating and testing i determined the brake pedal and centre pistons is causing the issue and master cylinders may be to blame which is why i am am not using the brake pedal. plenty of stopping power with front lever and outer pistons for now and its not eating my front disc and pads and i can actually move the bike out in the mornings without having to move the pads back from the front disc.
So yes hopefully as you say once both rear and secondary master cylinder assembly have been both switched out we should be good.
hope to have it back on the bench in a couple of weeks. Thanks for your help have a happy easter!
 
Larry (@Igofar) even has a presence over in a VFR forum

Nice graphic of our brake system on that post ... and nice write up of their problem and solution (the OP chose Larry's solution, of course) :thumb:

Rear brake locking up... rear center piston... FIXED!

So recently, I had the oh-so-common Honda (Goldwing, CBR1100XX, ST1300 and VFR800 combined braking system) rear brake lock up, dragging issue. The rear brake pedal felt mushy like there was air in the lines, and the rear brake barely stopped the bike. However, the rear caliper was binding the rea...
www.vfrdiscussion.com www.vfrdiscussion.com
.
 
core-aggie said:
Nice graphic of our brake system on that post ... and nice write up of their problem and solution
Click to expand...

Hmm. Now where have I seen that graphic and some of those photos before ? Not even a mention of st-owners or jfheath was given.
I may need to call in and have a word !
:(


I have some thoughts on this particular thread. I'll post when i can use my pc. This Ipad is very nice, but its hard work.
 
Don't feel bad John, I have no idea why they are talking about me either :rofl1:
 
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