There began a slight pulse feel in the application of the front brakes which leads me to believe that my rotors are warping.

First question, do I have to get new rotors or is there some way to refurbish them? The thickness is around 4.3mm so I have some room to work with.

Second, If my brakes are dragging causing overheating and warping, how do I tell for certain? If the answer is to just ride and touch them, then by that thought pattern, properly functioning automotive rotors get hot driving in traffic.

Third, if I have to get new rotors then are the ebay ones any good? Seriously, I don't have $300 dollars to just blow and I need to think economically as well as safety. I don't need a speech on the importance of brakes, that's why I am here to learn what can and shouldn't be done. Sorry for the rant but I have noticed that people get on soap boxes.

Thanks everyone.

 

Pulsing can come from a warped rotor or dragging caliper (leading to a warped rotor).
If you have the wrench skills, brake over-haul is fairly easy. Take it all apart, throughly
clean and then re-lube/assemble. If you're not upgrading to braided stainless lines
(something I highly recommend), you don't even have to remove the lines.

Check the how-to's for a couple of good picture-posted ones.

To check the rotors, the easy way is with a dial-micrometer, while on the bike.

The cheap way, lay the rotor on a piece of thick glass or marble/granite.
Run a feeler guage around the edge, trying to slip it under.
The thickest guage that will slip under anywhere around the rim, is half the run-out.
Check the manual for what that tolerance is.for your particular bike.
The manual will also note if you have the material to have the rotors turned true,
as well. You haven't commented on what particular make/model you're riding.

As far as determining if the brakes are dragging. Prop the front-end up and rotate the front tire by hand. you'll feel/hear it if thay are dragging.
You can check to see if the calipers are floating properly, by grabbing them and
push/pulling them side to side. they should move freely.

I've had good luck with e-bay , by noting the sellers rating and # of sales.
Generally they won't last long if they are cheating people.
Rotors are not something that are easily damaged, so odds are in
your favor buying used from a part-out.

Ern

 

Sorry about that. I ride a 95 CBR F3.

I think the left caliper is dragging since I just took it for a short ride and the left was hotter than the right. I measured the rotor by taking off the rotor from the wheel and measuring it from the side against a flat surface with a small ruler with very small increments. I don't have a dial micrometer yet but, it's on the list. Max runout is .3mm and my measurement is about .39 which is obviously out of specification. Note, my method of measurement is terrible so I suspect that this is a worst case scenario type of measurement since I fail conservatively.

I am now going to go check the caliper float and re-access from there. Where would I go to get the rotors true turned? I don't think that many of the automotive places like Auto Zone do that anymore.

I will replace the brake lines with stainless steel braid if that really helps but, it will have to be a winter project.
I will keep the post updated until satisfactory standards are achieved.
By the way, thank you for replying so quickly.

 

I know that oriellys turns rotors still...

 

I just looked at the float on the calipers. The pads are so close to the rotors that the degree of float couldn't be accessed by just trying to move the calipers side to side. So, I disassembled the brakes and found an error. The retaining clip for the brake pads was bent over and I bent it back to proper shape. I must have accidentally done that last night when I rebalanced the front wheel and reassembled the front end with minimal light, oops. Any ways, the pads moved properly and the float was fine.

I then took it for a ride and there was still that pulse feeling upon application of the front brakes but, I think there was improvement. How can you tell if the pistons need repair?
I am going to call O'Riley's tomorrow and see if they can turn the rotors.

 

The pistons themselves are normally fine but the seal can go bad. if this happens theres a seal kit. U just disassemble and replace.

 

Wouldn't fluid be leaking? There isn't any.

 

I recently rebuilt my rear caliper. I had one piston that was freezing up. During tear down I had to work it a few times to get both pistons to come out using compressed air. But mine wasn't leaking fluid at all and the seals were more than bad...

 

Well, I went to O'Rielly's and they said that the rotors won't work on their lathe. They tried but to no avail. I guess I will be buying new ones off of Fleabay. I will look at rebuilding the pistons here in the next day or so.

 

Thank you everyone for the assistance. I just cleaned the caliper pistons and the rotors run cooler which meant that there must have been some drag. There is still a pulse but I did some test brakes and the bike stops safely enough, I just won't be dreaming of riding on a track.

History: I bought the bike used three years ago for $1,000. It sounds mean, runs great, looks crappy in my opinion since it had been dropped. I wish I had more money to do all the fixes right now but, if that were the case, then I would be driving a F4i instead of an F3 that needs work.

This winter I am going to rebuild the forks, get new rotors, new front tire, and perhaps a new front wheel. I just put it in the wheel balancing stand again and noticed a slight wobble in the rim. Perhaps this is the origin of my problem with the brakes??????? I don't think so since I don't stunt my bike. Perhaps an older problem?? Perhaps I hit an Illinois pothole and now it's bent. I don't know but, what I can tell you is that this is a great learning experience. The tolerance is 2.0 mm and I am going to buy a dial micrometer in the next week and do some more measurements. At least my wife understands my purchasing of tools since I save so much money in maintenance.

Thanks again every one.