The brakes are linked... so doesn't matter if you just use the pedal or handle.. the front caliper will grab the front rotars causing the SMC to activate and thus lock up the rear.. Glad you got it home and I'm sure we can help you get it back to working properly.
Drivetrain lock-up?
- Thread starter Arellcat
- Start date
I am afraid this is all too common. On older motorcycles you are lucky to find anyone willing to look at it. In my case when our office machines reached "leagcy status" we got no more technical support at the manufacturer. No more parts help. Basically you were on your own with trying to trouble shooting a machine from hell. I think this is happening to old motorcycles too. I'm pretty sure Honda has pulled the plug a long time ago on their 1 800 technical help line.
You've diagnosed a bad SMC. It sounds like all you need is a very thorough flush of the brake system (do the clutch at the same time) and a new SMC. If the SMC is bad, any time you use the FRONT brakes, that moving caliper/SMC activates the rear brakes, so slowing and stopping using any method short of coasting to a stop or doing a Fred Flintstone (bare feet on pavement) will lock the rear brakes. Sounds like you have a handle on the problem now. Good Luck. Help is only a post away.
Older copiers are the machines from hell. Just finding someone to service them is an epic task.
Believe it. When I first started 50 years ago I was a trained Typewriter repair technician. Today you would be sol trying to get it repaired. But I could
There is a guy in Chicago who completely rebuilds IBM Selectric Typewriters and makes them like new. But yearly adjustments and cleaning? You are on your own....Believe it. When I first started 50 years ago I was a trained Typewriter repair technician. Today you would be sol trying to get it repaired. But I could
Wish I had a nickel for everyone of those I worked on. They were pretty good machines that had 2 tapes to rotate and tilt the plastic element that had the letters embossed on them. Only problem with them is the steel band tapes would break and they were a pita to thread back on the pulleys and do the adjustments.
OP
OP
A little knowledge is a dangerous thing, as they say, but even I knew enough that the SMC would kick in. Anyway, the machine is home and under cover now. Thing is, they did a full bleed on the system and the SMC movement is as expected, now, but it sure sounds like there is a blockage somewhere that is like a non-return valve. The Haynes manual seems to think it's feasible to rebuild the SMC, but then, Haynes reckons a lot of things are straightforward.
Oh, and the workshop guy said the bike was "high mileage" and I should expect problems. He didn't like it when I suggested to him that wasn't high for a Pan.
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The SMC needs to be inspected and if they don't actually know how to test it, the system will appear to be acting normally.. You need to spin the rear wheel and apply enough upward pressure on the SMC to make it stop the rear wheel. There's probably a lot of corrosion in your SMC and if the bike sits, it may retract and appear ok.
I'm not sure if anyone has successfully rebuilt the SMC - we have had a few who tried and failed.
High mileage...
Your shop guy is an idiot telling you to ride home without using the back brake.
The front brake activates the rear caliper.
This guys obviously does not understand the brake system on your bike.
Simply pull the smc boot back and I’ll be you see rust and corrosion, then you’ll have your answer in less than a minute…for free.
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Glad you made it home. The 1300's brake system is complex but as stated above, works fine with decent care and maintenance. It is really disappointing that your local dealer can't sort this out. What I believe you are experiencing is a small bit of crud in the secondary master cylinder. When you apply any brake, the piston closes off a small compensation port so it can pressurise the pistons in the calliper. When you release the brake, the master piston retracts and should expose that small port so that any remaining fluid pressure is released. If the small port is blocked, you end up with more and more trapped pressure and you get a locked brake. This same process happens in the SMC on the left fork leg, except in this case it is the use of the front brakes that causes it; the front left calliper moves with the disc and pushes on the SMC. So to avoid your repeating calamity, you have to avoid using BOTH brakes. Fun.
Your options are to disassemble and clean the SMC (if you have the tools and inclination) or replace the SMC with a new one. In either case there is a specific brake bleeding sequence that you MUST follow. As you will have spotted, there's plenty of helpful souls here, including many who have been where you are now. John Heath is a mine of information and has been very helpful to me when I have had brake-related questions.
Chin up, this can all be easily sorted. As a wise Taiwanese friend of mine told me, "If a problem can be solved with money, it is not really a problem".
Your options are to disassemble and clean the SMC (if you have the tools and inclination) or replace the SMC with a new one. In either case there is a specific brake bleeding sequence that you MUST follow. As you will have spotted, there's plenty of helpful souls here, including many who have been where you are now. John Heath is a mine of information and has been very helpful to me when I have had brake-related questions.
Chin up, this can all be easily sorted. As a wise Taiwanese friend of mine told me, "If a problem can be solved with money, it is not really a problem".
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- 63
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- Coquitlam British Columbia Canada
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- 2009 ST1300
If you can enjoy the luxury of pulling over and having a look at things at the first sign of trouble, you might be able to avoid a seqence of unfortuate events, but if you need to power through to get yourself to a safe destination, then it gets complicated, not just with this bike but with life, since you write the thread, you probably did the right thing, however as one of my favorite albums go, one thing leads to another.
- Joined
- May 27, 2021
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- 1,032
- Age
- 63
- Location
- Coquitlam British Columbia Canada
- Bike
- 2009 ST1300
It's like what John Lennon said about the '70s - didn't they suck, but man I'm glad you made it.
Don't trust Haynes manual for ST11/ ST13 / Pan European.
Especially the section on brake bleeding which is totally crap. Someone tried to save pages by combining the process for 4 systems (non linked, non linked ABS, linked non ABS and linked ABS) into a single process.
Download the Honda ST1300 manual.
Especially the section on brake bleeding which is totally crap. Someone tried to save pages by combining the process for 4 systems (non linked, non linked ABS, linked non ABS and linked ABS) into a single process.
Download the Honda ST1300 manual.
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STRider
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Why would this be preferred over just closing the bleed valve? Just wondering?
Igofar does NOT endorse clamping ANY brake or clutch line for any reason.
Apologies. Never meant to suggest Igofar had in any way advocated to pinch a brake line. Sorry for the confusing post, now deleted.
The clamp was not my idea by the way. I purchased one because I saw it mentioned either on this site or on the EU or OZ site some time ago.
Was lucky when I had a brake dragging issue, on an isolated gravel road, and could make it back to civilization in limp mode and avoiding touching the brakes. The SMC was replaced, but thought that if caught again in such a situation, I could bleed #7, leave it open, and pinch the brake line to prevent losing fluid, and be able to use what's left of the brakes on the way out of the boondocks. But not a good idea from what I can read here.
The clamp was not my idea by the way. I purchased one because I saw it mentioned either on this site or on the EU or OZ site some time ago.
Was lucky when I had a brake dragging issue, on an isolated gravel road, and could make it back to civilization in limp mode and avoiding touching the brakes. The SMC was replaced, but thought that if caught again in such a situation, I could bleed #7, leave it open, and pinch the brake line to prevent losing fluid, and be able to use what's left of the brakes on the way out of the boondocks. But not a good idea from what I can read here.
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Yes Sir.