Not sure where to pose this question...

I am working on an R56S front brake upgrade for my '05 R53. The used calipers I bought have torn caliper piston boots. It is my understanding that this is not an unusual occurrence.

I ordered the replacement parts, but I have not been able to find anything online that walks me through the process. Has anyone here done the rebuild process or can you point me to a site where I can learn more about it?

 

Try one of these.

James

 

Thanks, but I've already seen those. I was looking for one that specifically addresses the R56 calipers.

 

Calipers are all relatively the same as far as the rebuild process go. You're going to have to remove the piston, replace the shaft seal, install a new boot and reassembly. Theres not much more to that than that. I doubt the front caliper is a screw type. You'll more than likely need to use compressed air to remove the piston. Reference one of those videos, I'm sure they show this.

 

to remove the piston, i used a bike pump.. also replaced the rubber lines with steel braided ones. hard to explain but you'll have to use that cone type adapter for the bike pump to inflate like inflatable ***** in the rubber hose. but make sure you put like a piece of wood on the other side of the piston so when it flies out, it smacks the wood and doesn't damage anything.. hope that made some kind of sense.. putting everything back together, use some brake fluid so you don't damage the o-rings on the piston..

 

Yes, that does make sense. I think my major question is how the boot attaches to the caliper, which is why I was hoping to find an R56 specific tutorial. I guess it will be fairly self-evident when I take things apart.

 

The boot expands out into a machined slot and is held out by the piston. Don't try to remove the boot before the piston or you will wreck it. Unclip it from the piston, pump the piston out, pull the boot out.

This shows it pretty well. http://bmwe32.masscom.net/sean750/ca...alOnPiston.jpg

James

 

Thanks for that pic. It helps a lot to visualize what needs to be done.

 

I have a pair of calipers disassembled on my bench. LMK if you want pics of anything else.

James

 

Thanks! The final parts are scheduled to arrive this week and I hope to tackle it this coming weekend. Hopefully it goes smoothly, but if it doesn't I'll probably be back on here trying to pick your brain.

 

Post up some pics of the rebuild if you can, i did mine on the front of my R52, still on Gen 1 brakes, but for a while i was running the JCW 4 pistons.