Not sure why buy Tina's rear brake rotor warped by a quarter inch today.

Looks kinda like a bird bath with holes in it.

I thought it might be a stuck rear brake caliper but it collapsed easily so I don't think that was it.

Any ideas what causes this?


And no TD seafoam won't fix it!!!!!!!!!!!!!!!!

 

sounds like it got HOT real quick , then broke itself loose on another stop , have you pulled it loose & checked it out ? might just be some dirt

 

It didn't look that dirty and I cleaned it last week when I picked up a nail in the rear tire.

 

This is almost always caused by a blocked return drilling in the master cylinder....they are TINY!!!

You'll need to flush the caliper and jiggle a small nozzle cleaning wire in the two holes in the bottom of the cylinder (after you have syringed all the dirt out) and then flush it through and put new brake fluid in.

If you have time, dismantle to whole master cyl and clean all the passages...which is the correct way to do it but the above will get you home.

 

Spanners I greatly respect you but I have no idea what a return drilling is!!
Also what is a small nozzle cleaning wire?
I have never seen a wire with a nozzle.

By the way I am not being a smart *** I truly don't understand.

My truck and trailer got me home so I have all the time in the world so I guess I have to tear apart the caliper.

 

then return drilling is the return hole in the master cyl & the wire is just a piece of bailing wire that fits the hole , run it through so knock the dirt out , explaned in redneck talk

 

I think a drilling is what we refer to as an oil gallery.
The nozzle wire is a small gauge wire to poke through the gallery to clean out any debris.

 

Nozzle cleaning wires are available from welding suppliers and the like, used for cleaning oxy-acetylene torch nozzles.

If you take the top off the master cylinder and clean out all the gunge you will see a hole in the bottom.....if y'all look really close you will see a smaller hole to the left of the bigger hole (as you look down...so towards the rear of the bike) the tiny one you can hardly see is the one you need to clean but it got clogged with crap so y'all gotta git that there crud outta the system.

 

Nozzle cleaning wires = torch tip cleaner...you should have one in your tool box even if you don't own a torch..very handy

https://www.google.com/search?q=torc...e=off&tbm=shop

 

Thanks for the explanation's.
This will be the first brake caliper I have rebuilt so I ain't real familiar with the process.