Secondary Master Cylinder replacement

Joined
Aug 5, 2022
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New Bern, NC
My rear brake is dragging after dealer replaced the rear tire. They now say the secondary master cylinder has to be rebuilt and a bunch of related front and rear brake components on my 2015 bike needs to be rebuilt/replaced. I would prefer to replace the whole secondary master cylinder than rebuild it but I can't find a part number for a whole new SMC. Any thoughts/suggestions/assistance figuring this out would be greatly appreciated.
 
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Texas
How many miles are on the bike??

Have you been the sole owner, or did you buy it used??

Does the bike sit up without being ridden for months or weeks at a time??
 

Obo

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East Coast Canada
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'03 ST1300A
What year is the bike? There are different models of SMC for the earlier years 03, 04, maybe 05 - I forget when they made the changes.

Give Igofar a call on the phone. He can point you in a lot of directions for what to look for in case it's not the SMC (or it's more than that...)
 

Mellow

Joe
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08 is when it was slightly changed, added a slot so water wouldn't sit near the rubber boot.
 

Igofar

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02-07 where the original shorter versions, in 08- they made a one piece caliper to cut costs, and the SMC bracket had to be lengthened to work.
 
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Cleveland
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Only one guy here was able to rebuild his SMC successfully. I don't know how long that lasted. I might be wrong on the 'only one guy' but it is certainly fewer than the fingers on your hand.
 

Igofar

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Your going to need not only the complete assembly, but also 4 crush washers, and inspect the rear caliper mounting bracket for damage.
Also if the shop installed your rear wheel in the wrong sequence, this will damage the rear bracket, and can cause your rear caliper to lock up and drag.
 
OP
OP
Bright Rider
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Aug 5, 2022
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149
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New Bern, NC
How many miles are on the bike??

Have you been the sole owner, or did you buy it used??

Does the bike sit up without being ridden for months or weeks at a time??
About 42,000 best I remember. It's at the dealers right now waiting for me to decide to authorize them to do repairs or not. It was a police bike that I bought from them. I understand it did not sit up long. My first street bike and I was preping to start traveling and attending ST get togethers with forum members so I was riding regularly. I drove it a couple thousand miles in about a year and a half or so, mostly short trips of less than 50 miles. I drove it to dealer to install new tire, no issues from the SMC from the time that I got it until the day I let them change the tire. Noticed the back brake dragging on way home from dealer.
 
OP
OP
Bright Rider
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What year is the bike? There are different models of SMC for the earlier years 03, 04, maybe 05 - I forget when they made the changes.

Give Igofar a call on the phone. He can point you in a lot of directions for what to look for in case it's not the SMC (or it's more than that...)
2015. Thanks, I thought there may be some differences in 09 and earlier. Igofar has graciously offered to assist me so I will definitely give him a call when it's convenient for him. I appreciate all the help from the forum members on here, now and in the past from the topic/discussion threads on this complex subject. Everyone is so helpful, I am glad I am a member.

08 is when it was slightly changed, added a slot so water wouldn't sit near the rubber boot.
I thought I had read on here that there was a change somewhere in the 08 -09 range. Thanks for clarifying.

Only one guy here was able to rebuild his SMC successfully. I don't know how long that lasted. I might be wrong on the 'only one guy' but it is certainly fewer than the fingers on your hand.
That's what I seemed to gather as well from what I read on here. When the dealer started saying rebuild the SMC it heightened my concern. But I looked on a couple of parts sites and only saw rebuild kits for the part not a whole new part that I thought was preferred on here.

Your going to need not only the complete assembly, but also 4 crush washers, and inspect the rear caliper mounting bracket for damage.
Also if the shop installed your rear wheel in the wrong sequence, this will damage the rear bracket, and can cause your rear caliper to lock up and drag.
Thanks for the heads up. I think this is a possibility and may need some guidance to figure that out.
 

Igofar

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That's what I seemed to gather as well from what I read on here. When the dealer started saying rebuild the SMC it heightened my concern. But I looked on a couple of parts sites and only saw rebuild kits for the part not a whole new part that I thought was preferred on here.
Step away from the computer and calm down, I will call you tomorrow and we’ll discuss the entire system, and are probably going to find out they screwed something up working on it.
Talk to you tomorrow.
:WCP1:
 

Andrew Shadow

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I drove it to dealer to install new tire, no issues from the SMC from the time that I got it until the day I let them change the tire. Noticed the back brake dragging on way home from dealer.
That right there is an all stop, time to investigate moment.
Why did it become an issue immediately after they changed the rear tire? This means removing and reinstalling the rear wheel, and touching the rear brake.
Always possible that it is a coincidence.
But then again, always possible that isn't.
 
OP
OP
Bright Rider
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That right there is an all stop, time to investigate moment.
Why did it become an issue immediately after they changed the rear tire? This means removing and reinstalling the rear wheel, and touching the rear brake.
Always possible that it is a coincidence.
But then again, always possible that isn't.
I drove the bike there, no problem. I didn't even make it home before I realized it was now damaged. Coincidence? Stranger things have happened yes, the odds of the exact timing of it, probably about as much as one of us winning the lottery, possible but not likely. I think we're on the same wavelength. :)
 

STRider

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Step away from the computer and calm down, I will call you tomorrow and we’ll discuss the entire system, and are probably going to find out they screwed something up working on it.
Talk to you tomorrow.
:WCP1:
It's so good to see @Igofar firing on all cylinders again... Or would that be squeezing on all calipers? :)
 
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