Replacement brake parts

Joined
Nov 13, 2015
Messages
106
Location
Hudson NH
Bike
2005 ST 1300 ABS
STOC #
8875
Hello fellow STers,
I have been having issues with my rear brakes dragging, and eating pads. I have pulled apart and cleaned the secondary master cylinder, flushed/bled out the brakes, pulled the rear caliper and cleaned/lubed all the slide points. Issue comes and goes as it pleases. Brakes ok when driving, once in while I can feel some sticking when rolling up to a stop, but not bad, but sometimes I cannot back the bike up at all. This usually happens when the bike is cold, like in the morning when I want to head out for a ride. I would welcome any suggestions, and if anyone knows a good source for either a new secondary master, ( I know I can get used on Ebay, prefer new, if available.), or a rebuild kit, and also for the rear caliper, a new unit, or a rebuild kit. I have not called the dealer yet, figured would ask the group first, you all are a better source of info than some kid who rides crotch rockets behind the parts counter at the local Honda dealer. I just went Darkside CT on rear also, with a rear MC on front, and want to ride, but this dragging %&^$# is not doing my rotor any good, want this problem gone, for safety, and sanity reasons. Any advice and parts info is appreciated:confused:!
 
Last edited:
Joined
May 12, 2016
Messages
34
Location
Wisconsin
Bike
1998 ST1100
Pop the brake pistons out and replace the seals. Simple and cheap fix. Clean the grooves the seals are in, the corrosion behind the seals make them stick. Clean the pistons carefully (don't scratch). Some guys use toothpaste or chrome cleaner. NEVER SANDPAPER.
 
Joined
May 5, 2013
Messages
468
Location
Seattle
Bike
2016 FJR1300 ES
Pop the brake pistons out and replace the seals. Simple and cheap fix. Clean the grooves the seals are in, the corrosion behind the seals make them stick. Clean the pistons carefully (don't scratch). Some guys use toothpaste or chrome cleaner. NEVER SANDPAPER.
That's exactly what I plan to do very soon. Bought the parts already, including OEM pads for the first time.
 
Joined
Jan 8, 2011
Messages
7,064
Location
Arizona
Bike
2007 Honda ST1300A
Your going to get me flamed for my response on this thread :rolleyes:
I have never seen good results trying to clean a SMC and then put it back together. The rebuild kits are a waste of money, because its usually the bore that becomes egg shaped and causes the piston to stick.
If it were my bike, I would do the following; remove both of the incorrect fitment tires, replace the SMC with a new unit, do a correct bleed, rebuild all three brake calipers, lubricate the needle bearings, and only use OEM pads. With that out of the way, I do have a couple suggestions that you may want to try and look into.
When you removed and replaced the rear tire, did you follow the correct tightening procedure by tightening the stopper bolt before you tightened the axle nut? This is important (search threads).
As far as the car tire goes, I have had a couple people come through the garage claiming that they had the rear brake dragging....unable to roll backwards....rear brake keeps activating while riding down the highway (pavement seems) etc.
What it really turned out to be was the damn car tire (air pressure issue) was wide enough that every time a bump was hit, the sidewall flexed and tried to WEDGE itself into the plastic inner fender and or shaft drive.
I watched a guy try to "walk" his bike backwards in the driveway, and with each step, he was applying downward pressure on the seat, which caused the tire to scrape/drag on the drive shaft.
You may want to stick your head up in the rear fender area and look for signs of scraping or damage.
I've seen some folks even take a grinder and try and shave the driveshaft for clearance just so they could use a tire that was never designed to be used on their bike.
To that, I say, you can't fix stupid.
 
OP
OP
RedNHST
Joined
Nov 13, 2015
Messages
106
Location
Hudson NH
Bike
2005 ST 1300 ABS
STOC #
8875
Thanks for the advice. I should clarify, the tire conversion is new, the brake issue has been going on for a while, they are unrelated. Just wanting to ride, but the brake issue is getting old, want it gone. The rear tire I used fits with no modifications or clearance issues anywhere.
 
Joined
Apr 23, 2017
Messages
101
Location
Nantahala
Bike
2008 ST1300 ABS
I was always told not to just use brake fluid on the orings when installing them in or back in the grooves. I use a caliper grease. A tube is about $17? but will last you and a friend a life time. Brake fluid tends to swell the orings as they get older. I clean my pots with skotch brite in a rotating motion. Grease up the oings and make sure the dust seal one had some grease in the groove. I would do that before buying new pots.....as I call them. I had issues on one of my bikes with the pot being pulled back in to the caliper because they were too dry. Always thought it was a bleeding issue. I did buy new oring/seals after about 15 years...haha! and that helped to. No leaks before, just wouldn't extend out correctly. Anyhoo, that's MO :)
 
Joined
Dec 27, 2004
Messages
829
Location
Medina, Tennessee
Bike
2021 Tracer 9GT
STOC #
375
Yeah, I got chastised one time for expressing my extreme disapproval of running anything but a manufacturer approved motorcycle tire on a motorcycle.
 

SupraSabre

48 Years of SoCal Lane Splitting/Commuting-Retired
Site Supporter
Joined
Nov 20, 2005
Messages
9,500
Location
Cedar City, Utah
Bike
12/04 ST 1300s
2024 Miles
000145
STOC #
5901
A few years ago when my rear brakes locked up on my 2010, I "rebuilt" the SMC, the rear Master Cylinder and the rear caliper. It's been working great ever since!

And BTW, I just picked up a "new - opened box" SMC for $67 off ebay yesterday.
 
Joined
Apr 23, 2017
Messages
101
Location
Nantahala
Bike
2008 ST1300 ABS
I guess what I mean is, over the years the brake fluid does get on the orings, it has to in order to do the job which we all know. The book says to even use fluid to coat them during installation. I use a caliper type grease to coat the orings and dust seals as a protective barrier and lubrication. But as we all know, time will take its toll. I just get them off to a good start. I never heard of it before either til another board member from another forum told me about it. I bet I could have even used the old orings with the new grease, but after 100K and 16 years, figured I'd toss in some new orings :)
 
Joined
Jan 8, 2011
Messages
7,064
Location
Arizona
Bike
2007 Honda ST1300A
Its possible that your brakes dragging may be caused by something other than your rear caliper, or the secondary master cylinder.
Think of the brake system as a whole unit, and try not to focus on just one part, as you may just be trying to treat the symptom and not the problem.
While its true that the secondary master cylinders often fail from neglect, and/or failure to service them often enough (flush/bleed), several things can cause the brakes to drag and have the issues your having.
Just some of the things could be as follows: Failing SMC, Dry needle bearings in the SMC bracket, dirty/damaged pistons in ANY of the calipers, dirt that was forced behind the seals while pushing the pistons back in, dry seals, o-rings swollen from using spray brake cleaner, dry/dirty/corroded guide pins in ANY of the calipers, use of non-OEM brake pads, damaged/bent spring clips/ clips missing/loose/backwards, loose stopper bolt on the rear wheel, air in the system, incorrect assembly procedure of the rear wheel (stopper bolt must be tightened before the axle nut), non-OEM tire fitment, etc. These are but a few, and the list goes on and on.
I recently had a bike come through that had its brakes serviced from a Honda dealership, and the rear brake was dragging big time. A quick search revealed that one of the guide pins on the FRONT caliper was frozen and completely rusted (think of metal fence post exposed to sea water) preventing the caliper from floating, thus binding and causing the REAR wheel to drag. My guess is the shop never even took the calipers apart to inspect them, but simply pushed the pistons back and put new pads in.
To find the source of your problem, you must examine all of the parts of your brake system. Start with the front calipers, and work your way back, checking EVERYTHING.
Let us know what you find.
 
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