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Discussion Starter #1
So I noticed one of my front wave rotors is warped and since Im poor ill probably pick up a set of used OEM from Ebay or something. Im thinking I'll bleed the brakes as well as clean the callipers around the same time. My pads still have a lot left so what I've been told is that its fine to keep them?

What I'm wondering is there a specific order that I should do this or doesn't it matter at all? Im thinking change rotors, clean callipers while the wheel is off and lastly bleed the brakes. For the rear I'll just take the calliper off, clean it then put it back on and bleed it. Is that OK?
 

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So I noticed one of my front wave rotors is warped and since Im poor ill probably pick up a set of used OEM from Ebay or something. Im thinking I'll bleed the brakes as well as clean the callipers around the same time. My pads still have a lot left so what I've been told is that its fine to keep them?

What I'm wondering is there a specific order that I should do this or doesn't it matter at all? Im thinking change rotors, clean callipers while the wheel is off and lastly bleed the brakes. For the rear I'll just take the calliper off, clean it then put it back on and bleed it. Is that OK?
1. remove front brake caliper bolts. Then remove the calipers from there placement on the rotor. use a bungee cord to support the caliper by wrapping it around the lower triple tree. Don't let them just hang by the brake lines, it's not the best for them.
2. remove the front axle and pull out the front tire, forgot to mention, you will need a front stand for this project.
3. remove both front brake rotors from the rims. I believe these or torx bolts so run down to the store to get the right size. These things are gonna be on there tight so you may want a breaker bar.
4. once both rotors are removed, you need to prep the new rotors. I'm not sure if there is a specific way you need to do this on bikes, but with cars all you need to do is wipe down both sides of the rotors with brake cleaner to get the manufacturing oil off the surface.
5. Place the rotors (one at a time) on the rim and reinstall the torx bolts (hopefully you didn't strip them when you removed them, they strip easy) Torque these down to spec using the criss cross star pattern (like you would when putting a car tire back on). Can't remember the exact torque spec off the top of my head, but it will definitely be in the service manual.
6. Remove the old brake pads, this involves removing the cotter pins and retaining clips. If you just need to clean and bleed the calipers, there is no need to disconnect them from the brake line. You can bleed them on or off where they bolt in.. all personal preference.
7. I PERSONALLY would get new brake pads that way you are starting with all fresh material, BUT you should be okay using the old brake pads if they have plenty of material still on them.
8. Bleed the brakes, install the new pads, put the front tire with the new rotors back on the bike and bolt the front calipers back on, if you need to do additionally bleeding to get air out do so now. make sure your brake fluid is to the full line. pump up the brakes to seat the pads on the rotors and take it for a spin.

For the rear, clean it, bleed it, and reinstall.

I hope this helps
 

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I'm more curious about the circumstances that caused them to warp. If they're at or beyond minimum thickness, mystery solved. Otherwise you'll want to check for things such as excessive drag, bent axle, damaged forks, etcetera.

EDIT: I'd also be inclined to chalk warped rotors up to them being aftermarket, if they're after market.
 

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Discussion Starter #4
Thank you r6Ben00 very helpful!

Intuit Im not sure actually but my guess is the previous owner went down since it was a race bike. How do you mean beyond minimum thickness, if the rotors are thinner than stock?

"EDIT: I'd also be inclined to chalk warped rotors up to them being aftermarket, if they're after market."

What does that mean exactly? They are aftermarket.
 

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Service manuals typically contain specifications for minimum rotor thickness. Measuring this with a micrometer is how one typically determines that it's time for replacement.

Aftermarket parts often are either sub-quality when compared to OEM, or are designed to trade-off durability for some other advantage, such as weight. (drive chains are the most common example of the latter)
 

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not everyone spends the money on important things like brakes. sad but true, these could just be some sketchy china ebay brake rotors.
most aftermarket companies (the good ones) will stamp or paint their name on the rotor carriers. can you see one?
 

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Discussion Starter #7
So I think I have to apologise for posting to soon. I just received my new stand and I lifted the bike up on it, I held a pen towards the calliper so the pen just touched the rotor and I span the wheel and although I know this may not be completely accurate I think it seemed like my rotors are not warped.

However, I still have a heavy pulsating feeling especially at lower speeds so I think I should take it apart and clean everything and then bleed the breaks. So what is the most basic stuff I can use to clean everything? Can I just use regular break cleaner and a toothbrush for the rotors, a rug and break cleaner for the rotors? And what about the pads?
 

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Discussion Starter #8 (Edited)
not everyone spends the money on important things like brakes. sad but true, these could just be some sketchy china ebay brake rotors.
most aftermarket companies (the good ones) will stamp or paint their name on the rotor carriers. can you see one?
Pretty sure mine are arashi wave rotors.
 

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So I think I have to apologise for posting to soon. I just received my new stand and I lifted the bike up on it, I held a pen towards the calliper so the pen just touched the rotor and I span the wheel and although I know this may not be completely accurate I think it seemed like my rotors are not warped.

However, I still have a heavy pulsating feeling especially at lower speeds so I think I should take it apart and clean everything and then bleed the breaks. So what is the most basic stuff I can use to clean everything? Can I just use regular break cleaner and a toothbrush for the rotors, a rug and break cleaner for the rotors? And what about the pads?
Kinda going off of this, i am curious to know what ya'll recommend for brake caliper cleaning. is the CRC brake parts cleaner safe to use? it's like the only brand available at most hardware/auto parts stores anyways. Flammable vs non-flammable? does it make a difference?
 

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For cleaning the caliper pistons just use brake fluid. For everything else on the caliper's simple green works well. I don't use brake cleaner anywhere there are rubber seals. Brake cleaner is a very harsh chemical and will destroy anything rubber. I only use brake cleaner on the rotors or pads themselves.
 

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Sooner or later the piston seals will start to go, the times I've seen thats been characterized by the pistons being very hard to free and prone to sticking. The worst one I saw was a 2000 bike where goop had built up in the ring seats, squishing them even harder against the pistons. With the seals removed, it needed a pick to scrape out the solidified gunk, a brass brush is helpful too- but go easy, no harsh steel wirewheels and powertools, don't want to scratch/abrade the caliper internals.
 

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For cleaning the caliper pistons just use brake fluid. For everything else on the caliper's simple green works well. I don't use brake cleaner anywhere there are rubber seals. Brake cleaner is a very harsh chemical and will destroy anything rubber. I only use brake cleaner on the rotors or pads themselves.
I know that brake fluid is corrosive on paint. Is the rear caliper coated in anything that you want to keep brake fluid off of?

So would you recommend dipping a sponge brush in some brake fluid and scrubbing the inside of the caliper?

I agree that brake cleaner is some really strong stuff, which is why i asked. figured that stuff would just eat through rubber. I gotta do a brake service soon and want to know how i should clean the inside of the caliper with the pistons still seated. Just take brake fluid and a sponge brush and get to cleaning??
 

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Discussion Starter #14
So youre saying use brake fluid for the pistons and simple green for everything else? I saw some videos where they use brake cleaner and scotch brite for the rotors that seemed good. But what about the pads?
 

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Once a year, or if I have the wheels off for some reason, I clean the pads with brake cleaner, then acetone, followed by deglazing by briefly lapping them on a piece of sandpaper against a flat surface. Same treatment to the brake rotors, though I don't remove those, just scrub both sides with sandpaper. Not trying to remove material, but to scrape the surface.
 

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I know that brake fluid is corrosive on paint. Is the rear caliper coated in anything that you want to keep brake fluid off of?

So would you recommend dipping a sponge brush in some brake fluid and scrubbing the inside of the caliper?.....
No. You want something that won't make such a mess. I use an old toothbrush. A little brake fluid goes a long way. Dave Moss has videos of cleaning caliper pistons that offers some good tips. Remember this is just for cleaning the pistons. You want to minimize getting brake fluid all over the place, stuff is messy. Once My pistons are clean and none are sticking I'll push the pistons all the way back in then wipe down the entire caliper real well with Simple Green to get any brake fluid off the caliper, etc.

I believe there is a write up on the forums somewhere if you need a step by step on how to proceed. The key is to not push the pistons out to far where they pop out. Everyone has their own way of tackling the job so just find methods that work for you.
 

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Maybe the previous owner bent the rotor while changing a tire. Maybe being on one side only suggests this even more. If there isn’t any visible damage or stress marks upon very close inspection, perhaps you just... bend it back with a rubber mallet?
 

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Discussion Starter #18
So I cleaned my callipers, pads, and rotors. It made it a lot better but I still have some pulsating as I come to a stop and it annoys me. When I was cleaning the pistons I couldn't get them all to move evenly when applying pressure and it was getting dark and I needed the bike for the next day so I had to put it back together. Could this be the reason for my slight pulsating?

Also, I looked at that Dave Moss video and he said he uses water with dish soap for the pistons, so what do you guys think, dish soap or brake fluid for the pistons?
 

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Most cases of "warped rotors" are actually just pad material deposits on the rotor. For bikes, you definitely have the possibility that someone dropped the wheel or dropped the bike and actually bent it, of course. However, since yours looks straight, you probably just have uneven friction due to deposits. This can happen if you do some heavy braking and heat up the rotor then get stuck at a stoplight and keep the front brake on, for example. Use a scotchbrite pad to rub down both sides of the affected rotor. Do enough that you have a new clean surface. From there, opinions vary as to how you should go about bedding in the pads to the new surface, but that's a whole 'nother discussion.
 

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Discussion Starter #20
Most cases of "warped rotors" are actually just pad material deposits on the rotor. For bikes, you definitely have the possibility that someone dropped the wheel or dropped the bike and actually bent it, of course. However, since yours looks straight, you probably just have uneven friction due to deposits. This can happen if you do some heavy braking and heat up the rotor then get stuck at a stoplight and keep the front brake on, for example. Use a scotchbrite pad to rub down both sides of the affected rotor. Do enough that you have a new clean surface. From there, opinions vary as to how you should go about bedding in the pads to the new surface, but that's a whole 'nother discussion.
I already did clean the rotor surface and it did get a little better but there is still some pulsating. Thats why im wondering if it might be caused by the fact that my pistons did not come out evenly.
 
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