[ummbikes]

Hayes Monkies,

Is there any special trick to doing this? I have the caliper apart and will be replacing the pistons and square seals. Seems straight forward. Is it? Any help would be great.

Thanks

Rob

 

[oldfart]

I think its pretty easy. Not very many parts and they only go in one way. The pistons can be hard to get out. I used a foot pump conected to the brake line to pop them out. Or at least one. I think I just pulled the other out with pliers because I damaged the post any way. I'd avoid sharp tools to remove the seals and go with a sharpened toothbrush or something like that to pry the old ones out. You should probably have a torque wrench to reasemble too. You'll want equal bolt tension so the caliper doesn't distort and leak. Not absolutely needed because I didn't have one when I did mine and its still working 2 years and a couple hundred rides later.

 

[ummbikes]

Originally posted by oldfart
I think its pretty easy. Not very many parts and they only go in one way. The pistons can be hard to get out. I used a foot pump conected to the brake line to pop them out. Or at least one. I think I just pulled the other out with pliers because I damaged the post any way. I'd avoid sharp tools to remove the seals and go with a sharpened toothbrush or something like that to pry the old ones out. You should probably have a torque wrench to reasemble too. You'll want equal bolt tension so the caliper doesn't distort and leak. Not absolutely needed because I didn't have one when I did mine and its still working 2 years and a couple hundred rides later.

Thanks, my wife had some "orange sticks" which I guess are used for some chick nail maintance or something. They worked great, and are a fairly soft wood. Did you clean the calipers while apart? I'm half tempted to buy the "polishing" kit for my dremel tool and polish the housing:devil: Vanity baby, ya!

 

[jonikl]

yeah you have to have a lot of damn pressure to get em out. Watch out though, or "you'll pop your eye out".
This doesn't make sense. when you're replacing the piston anyway, why would you need to worry about damaging the piston. I just pull em out with needlenose.

Make sure you lube the pistons and the square seals with fluid for about 5 minutes. Not necessary but it's better to do it than not. You're less likely to scratch the piston and the fluid helps make a tighter seal. Make sure the little dimple on the back of the piston isn't dry. Also. Whatever you do, push the pistons back in by pushing your thumbs on the edges of the piston as to not damage the new piston. you probably knew that I'm sure. Common sense

I wouldn't take a dremel to it though. You might overbuff, and remember my caliper leaking out of the caliper body itself.
Just take your time with some isopropyl alcohol and a lint free swab.

 

[ummbikes]

Originally posted by jonikl
yeah you have to have a lot of damn pressure to get em out. Watch out though, or "you'll pop your eye out".
This doesn't make sense. when you're replacing the piston anyway, why would you need to worry about damaging the piston. I just pull em out with needlenose.

Make sure you lube the pistons and the square seals with fluid for about 5 minutes. Not necessary but it's better to do it than not. You're less likely to scratch the piston and the fluid helps make a tighter seal. Make sure the little dimple on the back of the piston isn't dry. Also. Whatever you do, push the pistons back in by pushing your thumbs on the edges of the piston as to not damage the new piston. you probably knew that I'm sure. Common sense

I wouldn't take a dremel to it though. You might overbuff, and remember my caliper leaking out of the caliper body itself.
Just take your time with some isopropyl alcohol and a lint free swab.

Ya, I forgot about your caliper leak, you should warranty that sucker!

 

[Big hit]

When I rebuild the calipers I pop the pistons out i just hit the brake lever without the disk or anything else between the pads..they pop out enough that you can easily take a pair of needlenose to get them out the rest of the way