09PA Brakes Grabbing - Resolved

[Igofar]

Don't feel bad guys, I'm clueless as well about what causes the damage
I do know that some of the bikes that these damaged brackets came off of had a lot of issues and damage going on in various areas.
Stopper bolts being loose were my first thought of the spirals, but then I've found them so tight that I needed a 1/2 inch impact to remove them.
Several bikes had destroyed flange (driven bearings). That may have contributed to the cause.
I've had one that the rear brake rotor was glowing cherry red, I KNOW that heat may have had something to do with that as well.
The pattern I've seen lately, is folks that have been riding their bikes with the brakes dragging, without knowing it, do cause heat, damage their flange bearings, and almost every bike that I've had to replace the rear bracket on had JUST bearing grease or (dare I say it) Moly 77 paste on it.
Your guess is as good as mine, I'll keep searching for the answer.
I know several of you guys service your own bikes, and some of you have very high mileage, and have not seen any issues arise.
I on the other hand see 4 to 6 bikes per month, so I probably see more damaged and neglected stuff that most owners.
And most of those are PD motors, auction bikes with scary history, and bikes that folks rode into the ground with little or no service work done.
My comment was not a jab at Dave.

 

[dduelin]

The last time the SMC failed I was on I-75 and the rear wheel locked. That scared the hell out of me when it skidded. The officer had to push on the SMC while I limped it to the right shoulder. I can see how it moved just enough up and forward to go out of alignment and cause the current problems.

Do doubt that would scared me too!

How can the bracket move up and forward if the axle is in place and the stopper bolt is installed?

 

[dduelin]

I think he is talking about the SMC ?

But at the rear, the stopper bolt just goes through the hole and stops the bracket from spinning around the axle. The hole is elongated to allow for expansion, I guess. My thought was that if the rear wheel / bearings / axle is installed incorrectly, it may allow a bit of unwanted movement to develop. I can see that might be possible, but I've not had the bits in my hand to test how feasible it is. Next time I have the wheel off. ........

If he is talking about the SMC it’s confusing jumping from a bent caliper post to an SMC issue.

 

[aniwack]

When the SMC failed it had to be pushed backwards to release the brakes.
The torque of the brake locking pushing forward on the aluminum bracket for the rear caliper could cause it to move just enough out of alignment. Was that worded better?

 

[dduelin]

When the SMC failed it had to be pushed backwards to release the brakes.
The torque of the brake locking pushing forward on the aluminum bracket for the rear caliper could cause it to move just enough out of alignment. Was that worded better?

Yes, thank you. Regarding the torque of the rear brake locking up..... my thoughts in post #21.

I hope the new bracket fixes it all up. I think Michael asked for a picture of the new one compared to the old one. That would be informative.

 

[Igofar]

Dave, I may have posted a picture of a couple damaged ones next to a new one in the prior thread that was mentioned.
If not, I'll try and take a picture of the New/Old ones for everyone.

 

[mortenk]

I will add one observation that may be helpful: I once installed the larger glider pin for the rear bracket at a slight angle (cross threading). I didn't notice when I put the bike together, but it resulted in my rear brakes dragging and pads wearing very unevenly. They would basically wear in one end only because the bracket was forced to be at a slight angle. It took me over a month and two sets of pads to find the culprit. Once I removed the glider pin and installed it properly, my brakes started working properly. I was worried that I had damaged/bent the bracket during this period, but surprisingly it seemed to be OK.

 

[aniwack]

No progress this weekend. Parts still haven't come in.

 

[aniwack]

This may be a stupid question with a very good explanation, but I have just been looking in detail at the photos you posted Last week. Post #14, Jan 6.

These 3 images. I am assuming that the first two are the rear caliper ?

I've separated the photos from the quote so I can answer your question.
View attachment 249920Pic #1. The tire has come off and I'm holding my phone at a funny angle. Don't worry it's not you.
The bolt you see on top is the connection to the Sub-Assembly. It's in the right place.

View attachment 249921 Pic #2. The rear caliper is gutted for cleaning. And boy was she dirty...
What you're asking about is the guide bolt. It's just there, there's nothing special about it at this point until the caliper goes back on.

View attachment 249922 Pic #3. BRACKET SUB-ASSY., RR. 43290-MCS-G01

 

[CYYJ]

Michael @CYYJ - and anyone else looking in - can you scrutinise this and yell out if I have made a massive error in interpreting what I see from @aniwack's photos.

I will do so, but not until tomorrow, I will be on a plane all day today.

Michael

 

[aniwack]

Larry said I should give away tickets to a ballgame to the first person that figured it out.

The boot was stuck during removal.

 

[aniwack]

Day 4 of working. Parts are in and I completed the rebuild of the caliper. New seals, new bracket, and a thorough cleaning of the pistons. The manual called for the caliper to be separated to allow for the pistons to be removed, that was put back together and torqued to 24 ft lbs per the book. I followed the torque values for everything else from the book and got everything back together in about an hour.
I‘m expecting a call from the White Courtesy Phone on Wednesday with the sequence to reprime the brake lines. I went to Tractor Supply and got a 60cc syringe and got the MotionPro 08-0143 Brake Bleeder from Amazon.

 

[CYYJ]

I think that Larry ( @Igofar ) identified the root cause of this problem in his post #27 above, when he wrote:

...I do know that some of the bikes that these damaged brackets came off of had a lot of issues and damage going on in various areas.
...I see 4 to 6 bikes per month, so I probably see more damaged and neglected stuff that most owners.
And most of those are PD motors, auction bikes with scary history, and bikes that folks rode into the ground with little or no service work done.

In the aircraft industry, we have a term "BER" - it means "beyond economical repair". It doesn't mean that the problem can't be repaired, it just means that it might not make sense, in the big scheme of things, to pursue repair & restoration to original specification.

As the ST fleet gets older, and bikes that have been 'ridden hard and put away wet', with no service history or a questionable provenance (police, etc.), come onto the market, buyers will need to look more closely at the service history (or lack of it) and the provenance of used STs, because for sure, some of them are going to be BER. They might still start and run, but the cost of maintaining them in - or restoring them to - safe and reliable condition will be enormous.

Michael

 

[aniwack]

We finally have a resolution!! I've completely rebuilt the rear caliper and she like to roll. Literally.

Major major kudos to the Dr. @Igofar White Courtesy Phone. Spoke at length with Larry to ensure that I had the right sequence to prime the system. I picked up a 60cc syringe from Tractor Supply and 5/16"clear tubing from Ace Hardware and we are off to the races! Used 40 oz of brake fluid to ensure everything properly flushed (it was naaasty!!). Put everything back together and there she is all ready to go riding.

Thank you everyone for your feedback during this two week adventure. Next up will be cleaning the front calipers and maybe a long ride.

 

[Igofar]

We finally have a resolution!! I've completely rebuilt the rear caliper and she like to roll. Literally.

Major major kudos to the Dr. @Igofar White Courtesy Phone. Spoke at length with Larry to ensure that I had the right sequence to prime the system. I picked up a 60cc syringe from Tractor Supply and 5/16"clear tubing from Ace Hardware and we are off to the races! Used 40 oz of brake fluid to ensure everything properly flushed (it was naaasty!!). Put everything back together and there she is all ready to go riding.

Thank you everyone for your feedback during this two week adventure. Next up will be cleaning the front calipers and maybe a long ride.

No wonder it would not roll, you were holding it back with your foot
Glad things worked out for you.
You were a good student weed hoppa

 

[aniwack]

Quick follow-up: I was having some residual issues with the front right not fully releasing. A call to the White Courtesy Phone and Larry said to clean the front caliper pistons. With 76500 miles of buildup they were extremely dirty. I used some 550 cord (known as paracord) soaked in brake fluid then rubbed the pistons down. A slight dab of silicone before sliding the pistons back in and now the fronts are moving freely. @Igofar i can’t praise you enough bro.

 

[DsrtRngr]

I've been having rear brake issues too, on my '05 with 30k miles. I found that on the bracket, the forward alignment hole for the black pin has become oblong. Maybe if someone has photo of the way it should look, they could post it. Here's 3 images of mine.

3 photos / google album