Rear caliper piston won't retract - any hints/help?

[BamaJohn]

From old threads, it seems that this is a known issue: BaJaRon posted in 2022 the following:
"A more common problem than would be expected. Once the piston detaches from the threads, it's a bear to get it to re-engage. As you have discovered. You have to apply a good deal of pressure to collapse the very strong spring behind the piston. Unfortunately, this is difficult to do with the caliper attached to the brake line. The threads are fine so the piston needs to be perfectly mated, flush with the threads to avoid cross threading them.

It seems that the adjustment has little if any reserve run-out. So that when the pads are worn too much, the piston disengages on its own.

As discussed, you may need to remove the caliper to give you the ability to apply the needed pressure. If you do. Raise it up so that you drain as little as possible from the system. This will make bleeding easier.

Good luck."

This happened to me Sunday on my 2020 Spyder RT Base and I'm asking if anyone knows of a used caliper for sale or an in-stock caliper, Please PM me.
My brake pads were Very Thin, but not bare metal and the piston won't retract (BaJaRon's tool, clockwise). Caliper is on my work bench, but I have a week-long trip on July 5.
Thanks in advance for any help.

 

[BamaJohn]

From old threads, it seems that this is a known issue: BaJaRon posted in 2022 the following:
"A more common problem than would be expected. Once the piston detaches from the threads, it's a bear to get it to re-engage. As you have discovered. You have to apply a good deal of pressure to collapse the very strong spring behind the piston. Unfortunately, this is difficult to do with the caliper attached to the brake line. The threads are fine so the piston needs to be perfectly mated, flush with the threads to avoid cross threading them.

It seems that the adjustment has little if any reserve run-out. So that when the pads are worn too much, the piston disengages on its own.

As discussed, you may need to remove the caliper to give you the ability to apply the needed pressure. If you do. Raise it up so that you drain as little as possible from the system. This will make bleeding easier.

Good luck."

This happened to me Sunday on my 2020 Spyder RT Base and I'm asking if anyone knows of a used caliper for sale or an in-stock caliper, Please PM me.
My brake pads were Very Thin, but not bare metal and the piston won't retract (BaJaRon's tool, clockwise). Caliper is on my work bench, but I have a week-long trip on July 5.
Thanks in advance for any help.

UPDATE: I found a new caliper in Illinois, and it's being shipped to me. Thanks for your interest.

 

[BajaRon]

I am sorry that you have encountered this issue. But you should be able to re-engage the piston on your current caliper. If you're looking at getting a replacement, you'll have to remove the current caliper from the brake line anyway. Once you put the caliper on a bench where you can get good leverage and correct alignment, you should be able to get it back together.

You can, if you like, ship it to us and we can do that for you. There would be some shipping and labor cost. But probably much less than even a used caliper that might have other issues.

And what if it happens again? You may end up with a few calipers on your shelf.

 

[BamaJohn]

Thanks Ron.
I just might ship the original caliper to you to remedy the piston. I'll call to discuss.
I already removed the caliper and have it on my work bench, cleaned up, and ready for repairs.

Due to time constraints and the uncertainty of refitting the caliper piston, I bought a new one at noon today, which I hope to have in hand by Friday.

Has anyone found why there's no stop on the piston assembly to prevent this from ever happening? I believe this same part number (705600989) is good for all Brembo-fitted Spyders from 2013 till now... if that's true, Can Am's had plenty of time to remedy the issue.

This is the tool I have on order that might help, but I'm really concerned that I might screw up the threads.

 

[BamaJohn]

I am sorry that you have encountered this issue. But you should be able to re-engage the piston on your current caliper. If you're looking at getting a replacement, you'll have to remove the current caliper from the brake line anyway. Once you put the caliper on a bench where you can get good leverage and correct alignment, you should be able to get it back together.

You can, if you like, ship it to us and we can do that for you. There would be some shipping and labor cost. But probably much less than even a used caliper that might have other issues.

And what if it happens again? You may end up with a few calipers on your shelf.

I hope to not let this happen again, now that I am made aware that it's possible. My Spyder had original pads on it with 29,000 miles... I'll be watching the EBC pads very often!

 

[BajaRon]

I hope to not let this happen again, now that I am made aware that it's possible. My Spyder had original pads on it with 29,000 miles... I'll be watching the EBC pads very often!

We have run into this issue on occasion with customer's bikes. They were still within wear spec (just barely) and the piston threads had disengaged. Personally, I think it is a flaw in the piston itself. Maybe there is a variation in thread depth? I don't know. But it would seem to me that if BRP/Brembo would add a thread or 2 to the piston, this could be avoided. Just speculation on my part as I have not researched it. But I don't see any reason to go to the effort unless I were planning on making replacement pistons. And adding threads could create its own issues. It is a surprising situation, to say the least.

 

[BamaJohn]

Well, it's now 9 days till departure for UNrally '24 in Arkansas, and the Gremlins; Banshee; Rougarou; and Marie Laveau have all teamed up to place as many obstacles as possible in the way.

6/25--A new rear brake caliper was ordered...-in stock in Southern IL. Supposed to deliver 6/27-28 via USPS ;
It went to STL first;
6/27 (today), USPS says it's in PORTLAND OREGON!- not Alabama! I can only deduct that the routing system at USPS is directionally-challenged!!!!
The shipper is working with USPS to see what's real, and what can be done.
Did I mention that I don't like drama?........

 

[BajaRon]

Well, it's now 9 days till departure for UNrally '24 in Arkansas, and the Gremlins; Banshee; Rougarou; and Marie Laveau have all teamed up to place as many obstacles as possible in the way.

6/25--A new rear brake caliper was ordered...-in stock in Southern IL. Supposed to deliver 6/27-28 via USPS ;
It went to STL first;
6/27 (today), USPS says it's in PORTLAND OREGON!- not Alabama! I can only deduct that the routing system at USPS is directionally-challenged!!!!
The shipper is working with USPS to see what's real, and what can be done.
Did I mention that I don't like drama?........

It happens. We had a customer in Sweden order a part. We shipped it USPS. His Swift Code (international name for Zip Code) was the same as a small town in Oregon. Even thought the label for an International package is completely different in size, shape, and detail, the USPS shipped this package to the small town in Oregon. The town is so small and remote that they don't deliver. Instead, they email the recipient that their package is ready to pick up. So, you guessed it. They emailed my customer in Sweden that his package was ready for pickup in Oregon.

You can imagine that my customer was not overly thrilled with this development, to say the least.

My first lease payment to the owner of the building we now occupy was mailed (as she requested) even though she lives not too far from the property. We hand delivered it to our local USPS. It went from our town in Greeneville, TN to the distribution center in Knoxville, TN. From there it went to Nashville, TN where it sat for a period of time waiting for someone to figure out what was up. In the meantime, my payment was late and the owner called to see what was up. I told her, 'The check is in the mail'. Which I think she's heard before.

The check ended up delivering 10 days later to an address that was virtually around the corner. The postage mark confirming that it was sent the day I said it was helped.

I sent a sway bar kit to a customer in Australia. He emailed a few weeks later asking why it had not yet delivered. I did some checking and found it was sitting somewhere in Chili South America. The USPS said they would get it fixed and it's next destination was Austria (not Australia). I think Austria gets a lot of packages ment for Australia so they forwarded it on, but for some reason, it went to Japan. From Japan it finally arrived in Australia. That customer had a great sense of humor. He commented that if he ever decided to travel the world, he would simply purchase some USPS postage and ship himself to his final destination.

I've been shipping with all carriers since 1998 and I've got a good number of stories. Believe me, they all have their issues, and your's is not all that unusual. Sorry for the drama. The good thing is, they don't charge extra for it!

 

[BamaJohn]

Thanks for you post to put things in balance. Thanks to a friend who will loan me her rear caliper, that will still allow me to attend the UNrally July 8-12.
Signed:
Blessed to have great friends

 

[BamaJohn]

Thanks Ron.
I just might ship the original caliper to you to remedy the piston. I'll call to discuss.
I already removed the caliper and have it on my work bench, cleaned up, and ready for repairs.

Due to time constraints and the uncertainty of refitting the caliper piston, I bought a new one at noon today, which I hope to have in hand by Friday.

Has anyone found why there's no stop on the piston assembly to prevent this from ever happening? I believe this same part number (705600989) is good for all Brembo-fitted Spyders from 2013 till now... if that's true, Can Am's had plenty of time to remedy the issue.

This is the tool I have on order that might help, but I'm really concerned that I might screw up the threads.

Turns out that the tool shown in my post above will NOT work because the little nibs on the bottom piece don't fit the Spyder's rear caliper piston; PLUS, the BajaRon piston tool won't fit onto the shaft of the pictured tool!

 

[BamaJohn]

Final Update: The new Caliper arrived and is installed. It took a LONG time and a LOT of Dot4 to get rid of all the air. And tomorrow morning the muffler will be reinstalled, completing this ordeal that began with changing the rear tire and dropping in new brake pads.
Thanks to a friend for his help and use of a vacuum pump.

 

[Mikey]

:congrats: