View Full Version : Pushing the piston in on caliper


Hero Danny
May 30th, 2015, 07:25 PM
So... I was taking my wheels off of my cbr600rr to get the tires changed and long story short while the tires were off the front brake was pulled by an idiot (not me, another idiot) and now the pads are pushed out too much and won't fit on the rotor....

Is there a simple way I can fix this without having to go through the bs of removing the pads? Is it possible for me to push the pistons back without damaging the pads? :/

Thanks in advanced everyone.

snapshot
May 30th, 2015, 08:28 PM
Ouch! That's a tough one.

I'd pull the pads so that I could make sure that things stay aligned as I pushed the pistons back in. As one piston goes in, the other will want to come out, so you have to secure it first. A correctly sized C-clamp is handy for that. Do the push-in by hand, though. You'll need to feel what's going on.

Luck,

J~

alex.s
May 30th, 2015, 08:28 PM
the caliper looks like a big C... one side of these calipers has pistons. inbetween the C are the two brake pads. use two channel locks or two c clamps or something and squeeze from behind the pistons on one side of the caliper, all the way over the two brake pads to the back of one of the brake pads. so that the channel locks are pushing on the brake pad backing plate and the outside of the caliper to squeeze the pistons in. clean the pistons first.

EsrTek
May 30th, 2015, 09:54 PM
Small piece of wood between c-clamp and brake pad, as centered as possible, and watch for even pressure as you push them back in.

dcj13
May 30th, 2015, 10:00 PM
You could leave the pads in place and try a pushing in a pair of thin wooden construction shims from Lowe's or Home Depot to spread the pads apart.

Motofool
May 30th, 2015, 10:34 PM
You could leave the pads in place and try a pushing in a pair of thin wooden construction shims from Lowe's or Home Depot to spread the pads apart.

I like this idea, as Hero Danny's new bike has eight pistons to push back simultaneously, if I am not wrong.

As all pistons are connected to one single pressure source, pushing back the pistons of one caliper may push out the other four pistons.

http://ecx.images-amazon.com/images/I/41oH%2BrtlhYL._SX355_.jpg

http://www.cyclepedia.com/wp-content/uploads/2007/10/CBR600RR_1721.jpg

Somchai
May 30th, 2015, 11:33 PM
Danny please don't misunderstand what I'm saying, but if you're not so sure about how to do this job, you could go an easy way and take a look in the bay where the calipers are quiet cheap to get, i.e. http://www.ebay.com/itm/07-08-Honda-600RR-Front-Wheel-Brake-Calipers-Set-/131388688004?fits=Model%3ACBR600RR&hash=item1e97604684&vxp=mtr or here http://www.ebay.com/itm/07-08-Honda-CBR-600RR-Front-Wheel-Brake-Calipers-Set-/131524919823?fits=Model%3ACBR600RR&hash=item1e9f7f020f&vxp=mtr
Your friend will be happy to share some money with you, I think.

Many guys change the calipers of the CBR 600 to a better system, bc Tokico calipers seem to be well known.

Good luck for you :thumbup:

cadd
May 30th, 2015, 11:51 PM
Ouch!!! Why would he/she pull the lever knowing the calipers were off the bike?!?!

Try using a small C-clamp and a piece of thin wood (grab some from the paint dept of Home Depot)....the ones they give out for free when you buy paint. Hopefully you have the tiny c-clamps that would fit in there.

subxero
May 31st, 2015, 06:23 AM
just use something to force them back into the caliper. If the pads are still good and you don't want to damage them trying something like a plastic pry bar or something of the likes. You can always use a screwdriver but can damage the pads. If there is enough to get a c clamp on then use that to force them back in. Whatever works, it's not rocket science.

One tip though. Often as the pads get worn the pistons need to come out further to get the worn pads to meet the rotor, then the brake fluid takes up the extra space inside the caliper as the pistons move out. Your brake level goes down so you put more in.

So if you force the pistons out, you will push that brake fluid back into the MC reservoir and there might be more fluid in the system than can fit back into the reservoir so take some fluid out of the reservoir as you push the pistons back in.

Hero Danny
May 31st, 2015, 10:27 AM
Just an update. I tried it once more and they were able to slip in. I don't know how but it was fine. Huh... I'm surprised they didn't push forward...

While I was down there I did apply some brake cleaner to the pistons.

Anyway, tires are on and i'm happy with them! :)

broken neck
May 31st, 2015, 12:07 PM
Ouch!!! Why would he/she pull the lever knowing the calipers were off the bike?!?!

People are magically attracted to any kind of levers, especially the male kind... So, if a male finds a lonely lever attached anywhere in the world, he'll be more likely pushed by its brain to pull that lever just get the feeling of the pressure against the inside of its fingers... If there's no feedback from the lever, they'll give it a second try right away to confirm the lack of feeling...

Only after the brain will kick in and start asking why there's no feedback, then the male might be tempted to find the reason and finding the rotor is missing and now the pistons are out of the caliper or simply remembers the wheel was off...

It happened to me with my mountain bikes and my ninja 250... Even if I was the one who took off the wheel. After a short lapse of time, my brain resets and here I go pulling my levers...

Whenever I took off a wheel, I try to jam a plastic piece between the pads to be sure the piston won't move...

Sorry, for the long off subject post, by I don't want to go cleaning the house, so I procrastinate everywhere I can...

Somchai
May 31st, 2015, 10:58 PM
Good to see that the problem is solved :thumbup:

Flying
May 31st, 2015, 11:23 PM
People are magically attracted to any kind of levers, especially the male kind... So, if a male finds a lonely lever attached anywhere in the world, he'll be more likely pushed by its brain to pull that lever just get the feeling of the pressure against the inside of its fingers... If there's no feedback from the lever, they'll give it a second try right away to confirm the lack of feeling...

Only after the brain will kick in and start asking why there's no feedback, then the male might be tempted to find the reason and finding the rotor is missing and now the pistons are out of the caliper or simply remembers the wheel was off...

It happened to me with my mountain bikes and my ninja 250... Even if I was the one who took off the wheel. After a short lapse of time, my brain resets and here I go pulling my levers...

Whenever I took off a wheel, I try to jam a plastic piece between the pads to be sure the piston won't move...

Sorry, for the long off subject post, by I don't want to go cleaning the house, so I procrastinate everywhere I can...

https://imgs.xkcd.com/comics/the_difference.png

Hero Danny
June 1st, 2015, 08:17 AM
People are magically attracted to any kind of levers, especially the male kind... So, if a male finds a lonely lever attached anywhere in the world, he'll be more likely pushed by its brain to pull that lever just get the feeling of the pressure against the inside of its fingers... If there's no feedback from the lever, they'll give it a second try right away to confirm the lack of feeling...

Only after the brain will kick in and start asking why there's no feedback, then the male might be tempted to find the reason and finding the rotor is missing and now the pistons are out of the caliper or simply remembers the wheel was off...

It happened to me with my mountain bikes and my ninja 250... Even if I was the one who took off the wheel. After a short lapse of time, my brain resets and here I go pulling my levers...

Whenever I took off a wheel, I try to jam a plastic piece between the pads to be sure the piston won't move...

Sorry, for the long off subject post, by I don't want to go cleaning the house, so I procrastinate everywhere I can...

Hahaha, thanks for the good laugh.

crazymadbastard
June 1st, 2015, 08:35 AM
Crack the bleeder loose also, two benefits- makes pushing the pistons in easier also flushes and does not push old fluid back into the system. Put a hose on the bleeder to catch the juice.