Rear caliper drag

Joined
Apr 19, 2011
Messages
40
Location
Chesapeake, Va
Bike
2007 ST1300A
My new to me 04 ST with 40, 000 mis' rear caliper is dragging. I've checked the SMC and it brakes and releases. It seems to only drag after the rear pedal is used. I've rebuilt the caliper and the slides all move smoothly and it has been bled. I noticed the pads aren't hitting the rotor evenly. I further noticed the caliper mount has some space between it and the swing arm where the guide pin goes though like something is out of alignment or bent???
ST caliper space.jpg
 
Please elaborate some so I know you are real.
I hope this is humor! Yup he’s real alright, Honda calls him when they can’t figure it out. Had his hands all over my bike, no regrets, learned a ton of knowledge and carry on the tradition.

By the way don’t ride that bike till you do exactly what he tells you to. You have an immediate issue that is life saving to address.
 
I hope this is humor! Yup he’s real alright, Honda calls him when they can’t figure it out. Had his hands all over my bike, no regrets, learned a ton of knowledge and carry on the tradition.

By the way don’t ride that bike till you do exactly what he tells you to. You have an immediate issue that is life saving to address.
You see something life threatening? Please elaborate!
 
What's your number?
hover your cursor over his blue screen name (left side of your window under his avatar). click on start conversation, and sent Larry your phone number and if you are time constrained, when are the best times for him to call you. Plan on him telling you exactly what is wrong with your bike...in detail.

I doubt you could find ANYONE, ANYWHERE who will give you as much information about any mechanical problem you might have as he will.
 
You see something life threatening? Please elaborate!
That is an extreme outcome, but rear brake drag can come from the secondary master cylinder not releasing line pressure after application, either due to corrosion seizure or fluid blockage. Ultimately this can result in a rear brake that locks on or overheats. A locked rear brake may cause an accident.

Your photo shows one of the fasteners backed right out, I assumed that was partial disassembly during your diagnosis?

I have travelled this path a bit; my story started with a draggy rear brake, I (foolishly) decided to remove the sliding pins for some lubrication with the calliper in place, and when I refitted the larger pin I somehow managed to cross-thread that so the two pins were no longer truly parallel. I have had plenty of garage experience and the cross-thread was not obvious when re-tightening. When tightened this pulled the back pad into firm contact with the rotor. My only solution was to replace the brake mounting bracket with a second hand part.

I disassembled and cleaned the pistons and seals, and then also did the same with the secondary master cylinder to ensure the one-way valve and cartridge were truly clean. There are some here that will tell you that that is also verboten but it is just hydraulics like the rest of the system. The Honda LBS works great but is unforgiving of skipped maintenance.
 
That is an extreme outcome, but rear brake drag can come from the secondary master cylinder not releasing line pressure after application, either due to corrosion seizure or fluid blockage. Ultimately this can result in a rear brake that locks on or overheats. A locked rear brake may cause an accident.

Your photo shows one of the fasteners backed right out, I assumed that was partial disassembly during your diagnosis?

I have travelled this path a bit; my story started with a draggy rear brake, I (foolishly) decided to remove the sliding pins for some lubrication with the calliper in place, and when I refitted the larger pin I somehow managed to cross-thread that so the two pins were no longer truly parallel. I have had plenty of garage experience and the cross-thread was not obvious when re-tightening. When tightened this pulled the back pad into firm contact with the rotor. My only solution was to replace the brake mounting bracket with a second hand part.

I disassembled and cleaned the pistons and seals, and then also did the same with the secondary master cylinder to ensure the one-way valve and cartridge were truly clean. There are some here that will tell you that that is also verboten but it is just hydraulics like the rest of the system. The Honda LBS works great but is unforgiving of skipped maintenance.
Your story about cross threading the larger pin is starting to sound familiar! You are talking about the pin that goes through the caliper and lands in the bracket and not the locating bolt / pin in the swingarm that keeps the bracket from rotating, right? When I took this apart, the caliper's larger bolt was very hard to turn. I had to use a ratchet the entire way out. I cleaned it out and am pretty sure it is correctly threaded and square. With the pads out of the caliper, the caliper slides very nicely on the two pins. I think it may have been cross threaded before I got to it. The boot was also missing. My inside pad is pulled up to the rotor as well and not hitting squarely on the rotor. It worries me that the bracket has space between it and the swingarm where the locating pin goes in. It seems like it could be bent???
 
Your story about cross threading the larger pin is starting to sound familiar! You are talking about the pin that goes through the caliper and lands in the bracket and not the locating bolt / pin in the swingarm that keeps the bracket from rotating, right? When I took this apart, the caliper's larger bolt was very hard to turn. I had to use a ratchet the entire way out. I cleaned it out and am pretty sure it is correctly threaded and square. With the pads out of the caliper, the caliper slides very nicely on the two pins. I think it may have been cross threaded before I got to it. The boot was also missing. My inside pad is pulled up to the rotor as well and not hitting squarely on the rotor. It worries me that the bracket has space between it and the swingarm where the locating pin goes in. It seems like it could be bent???
Yes the larger pin that the calliper slides on was the one that I messed up. I tried many times to reseat the pin straight but wasn't able to do so, so I just bought a used rear calliper from a wreckers (and got lucky that this was in great shape). If your back pad is being pulled onto the disc and not straight then you may have a similar problem.

I am less sure about the gap between the swingarm and the bracket by the stopper bolt; I am not near my bike to check that one, sorry.
 
I’m going to go out on a limb here, and guess you have more issues than you think.
Here are a few pictures of “witness marks” verifying things are not correct.
I’m standing by the :WCP1: call me tonight.
 

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If you followed the torque specs in the service manual for that pin that you removed, you may have done more damage than you realized because the torque spec is a misprint in many of the manuals.
Which means you over tightened it, and could have sunk the steel threads into the soft aluminum causing things to tilt.
 
If you followed the torque specs in the service manual for that pin that you removed, you may have done more damage than you realized because the torque spec is a misprint in many of the manuals.
Which means you over tightened it, and could have sunk the steel threads into the soft aluminum causing things to tilt.
What is the correct torque spec for the larger slide pin ? My Honda manual (2005 ST1300) listed 51 ft lbs I believe. Seemed excessive to me, fingers crossed I didn’t damage it further.
 
First off, those sliding pins should not be removed from the assembly. There is never a reason to remove them as the parts slide apart from each other.
51 ft lbs is INCORRECT and you will risk damaging your very expensive caliper by using that.
Besides the risk of cross threading stuff, that much torque may cause the steel pin to either attempt to pull out the aluminum threads, damage them, or cause the steel pin to sink into the soft aluminum assembly causing things to tilt and misalignment will occur.
Often folks see the 12mm nut (used to install the pin) and think it’s there to help take the caliper apart etc.
 
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