Rear brake binding and locking wheel
Posted: Thu Jul 26, 2018 7:28 am
Hi Guys,
I recently installed a new rear brake master cylinder on my 1989 FZR. I went for a Brembo master cylinder from an R6.
When trying to bleed the rear brake I broke one bleed nipple from the original calliper, as it was rusted tight! So i replaced the calliper with one from eBay that cost £40 (around $50-$60). So I fitted this one and after bleeding the whole system using the Wiki article about how to bleed a dry brake system I tested the bike.
After riding for a minute or two and using the rear brake a lot the pads started to bind on the disc and it all eventually got very hot until it all started smoking and the rear wheel binded!! Quite a scary experience!
Since then, I have split the calliper and push back the pistons. They seem to be free enough and I've re-greased them. When I put everything back together and bled the system again it's still binding the rear wheel. Once it fully locks when I'm riding I have to get off, disconnect the brake lever and calliper and move the calliper around a bit until it frees up.
Not sure if there's something that I've done wrong or if one part in the new system is broken. Here's a breakdown of the components:
Master cylinder - I've taken this apart and cleaned it. It's got the threaded bar from the original FZR master cylinder attached to it, as the R6 bar was very short.
Hoses - Has a brand new Hel braided hose.
Calliper - FZR600 calliper - One thing I noticed was that the pistons on this calliper move together. So when I push in one piston the other one pops outwards (when the calliper is together and filled with brake fluid.
Any help would be great. I've ridden it 3 times now and it's binded the rear wheel on each occasion.
I recently installed a new rear brake master cylinder on my 1989 FZR. I went for a Brembo master cylinder from an R6.
When trying to bleed the rear brake I broke one bleed nipple from the original calliper, as it was rusted tight! So i replaced the calliper with one from eBay that cost £40 (around $50-$60). So I fitted this one and after bleeding the whole system using the Wiki article about how to bleed a dry brake system I tested the bike.
After riding for a minute or two and using the rear brake a lot the pads started to bind on the disc and it all eventually got very hot until it all started smoking and the rear wheel binded!! Quite a scary experience!
Since then, I have split the calliper and push back the pistons. They seem to be free enough and I've re-greased them. When I put everything back together and bled the system again it's still binding the rear wheel. Once it fully locks when I'm riding I have to get off, disconnect the brake lever and calliper and move the calliper around a bit until it frees up.
Not sure if there's something that I've done wrong or if one part in the new system is broken. Here's a breakdown of the components:
Master cylinder - I've taken this apart and cleaned it. It's got the threaded bar from the original FZR master cylinder attached to it, as the R6 bar was very short.
Hoses - Has a brand new Hel braided hose.
Calliper - FZR600 calliper - One thing I noticed was that the pistons on this calliper move together. So when I push in one piston the other one pops outwards (when the calliper is together and filled with brake fluid.
Any help would be great. I've ridden it 3 times now and it's binded the rear wheel on each occasion.