Time to rebuild the calipers?

[shadowmagic]

So I stopped riding with my helmet on and now I hear some noise. It sounds like my brakes need work. I can hear them rubbing while I ride, the sound seems to change and dissipate when brakes are applied. Brakes work fine but I suspect its time to rebuild the calipers. That is one of the few things I haven't done to this bike yet. Any tips or advice from the masters? I already read the manual and it seems pretty straight forward but I know everyone in this group usually has a better way of doing something through experience 

[Jess from VA]

I don't know if this is your problem, but when my bikes sit for a while, the rotors get a bit of corrosion (not really visible).  I will have a bit more dragging noise when first riding after sitting (or spinning them up on the lift), but it soon disappears with running and brake use.  

Also, when I really clean my bike, I scrub the brakes, rotors and all with smaller stiff bristle brushes and a mild corrosive like S100 or auto parts mag wheel cleaner, followed by good rinse and leaf blower dry.  (For more intense cleaning, I use gun bore solvent and a pistol rod with old beater brass brushes on brakes and pistons)

The brakes are always smoother and quieter after.

My rotors have never been changed (60K and 107K) and are definitely worn with an outer lip, and may even be out of minimum speck, but all cleaned up they still work great.  

[shadowmagic]

Awesome, thank you for all the great info.

[Chrisj CMA]

I don't know if this is your problem, but when my bikes sit for a while, the rotors get a bit of corrosion (not really visible).  I will have a bit more dragging noise when first riding after sitting (or spinning them up on the lift), but it soon disappears with running and brake use.  

Also, when I really clean my bike, I scrub the brakes, rotors and all with smaller stiff bristle brushes and a mild corrosive like S100 or auto parts mag wheel cleaner, followed by good rinse and leaf blower dry.  (For more intense cleaning, I use gun bore solvent and a pistol rod with old beater brass brushes on brakes and pistons)

The brakes are always smoother and quieter after.

My rotors have never been changed (60K and 107K) and are definitely worn with an outer lip, and may even be out of minimum speck, but all cleaned up they still work great.  

The danger with letting them get too thin is cracking. Especially on a mountain road where they may get hot. Saving a few $$ is not worth it. If they are below minimum spec replace them. Friends don’t let friends ride on worn brakes.

[Jess from VA]

I understand Jeff.  Last time they were specked, they were OK.  I'm real easy on my bike brakes (and would never ride them on downhills, I'd use a lower gear).  Pads last me a long time. 

[RonW]

when's the last time you changed brake fluid, just asking.

[shadowmagic]

I redid my brake fluid a few months ago. I figured I would flush the system when I had my wheels off to put new tires and change out the bearings. I should have rebuilt them then but I got lazy lol

[rug_burn]

I only rebuild mine when the seal leaks, usually because I didn't chenge the fluid at least every other brake pad change.    I just compress the pistons all the way in using a c clamp, then empty the (then) full reservior with a turkey baster buld, and refill with the right fluid.   All you gotta do is keep the  fluid from becoming saturated with water, which will fall out of solution in cold conditions and corrode the caliper bore.   The solubility of water in brake fluid  increases when its hot, and decreases when it's cold.   The water corroding the aluminum bore is what causes the calipers to fail.