Juicy 7 Front Brake Squealing
Hello everyone, I'm new to the forums so hello! I recently purchased juicy 7s for my bike, and for a while I didn't have any problems with them. Lately, however, there is a really nasty squealing sound coming from the front wheel. I have narrowed down the problem to the rotor slightly rubbing against the pad while the wheel turns. To fix it I will take the wheel off, then try to put it back on as straight as possible. Then I will realign the caliper. Immediately after I do this the sound goes away. However, I will take it out to ride for a few minutes, and within five to ten minutes of riding down my street the squealing starts again. It is quiet at first, but gets louder the more I ride. Eventually it becomes an incredibly loud, continuous squeal. If I do the same procedure mentioned above it will temporarily fix the problem, but it will return after a bit of riding. The problem exposes itself much more quickly if I do a few downhill runs or any sort of trail riding that exerts extra force on the bike. Also, the sound will sometimes start again even if I don't use the front brake at all.
I don't know if this makes a difference, but I am using an old Manitou fork. I'm not sure exactly what kind it is, but it looks similar to this: http://i18.ebayimg.com/03/i/000/d1/cb/9e58_1.JPG, except the bottom part is blue and I think it is older than that one. It also has the rubber boots on it, and doesn't have that bar going across the bottom. One of the knobs says "TPC+" on it.
Tonight when I get home from work I am going to try realigning the calipers and use loctite to secure the bolts in place, we'll see if that works. Have any of you run into this problem, or have any suggestions on what I can do to fix it? The sound is really starting to drive me batty.
welcome to mtbr, kompile15!
if you use loctiite, make sure it is the blue one and don't use too much.
also make sure that the rotor is straight and the caliper is centered (don't just realign it by pulling at the lever, but make sure the rotor is centered and the pistons are moving the same distance)... I know you have done most of it but just make sure....
Hey crisillo, thanks for the response and sorry for my delay responding to you. After further examination I found that when I tightened the quick release, it was pushing the two sides of the fork together ever so slightly, causing the caliper to move closer to the rotor, causing the rubbing. I played around with extra washers in the hub until I got the fork to stay straight. However, now the other side of the front piston (the right side when looking at it from a seated position on my bike) will not fully return to its starting position. Furthermore, the front brake is now very loose and it will compress all the way to my handlebar. I'm wondering if I should bleed my brakes to fix the problem, but I don't see how that could affect the piston returning to its starting position. I can push it back with a flathead screwdriver like it says in the manual, but it will just keep going back out. I have attached an image, it doesn't do a great job but I think it will work. I also added a picture of my bike since it seems like people like to show off their babies, and I wanted to join the club .
Thanks again for the response!
*Edit* After reading through the forums it looks like I have a sticky piston due to either an air bubble or one of the other various reasons a piston gets sticky. I'm going to order a bleed kit and try to get this straightened out. This forum is a wealth of knowledge, thanks so much you guys!!
Last edited by kompile15; 01-21-2008 at 10:36 AM.
well..in use the pistons don't go all the way back in the bore, they always go back a little bit that's how they self adjust for wear), however they should be moving at least a similar amount...
as you already saw, just follow the recommendations in other threads for sticky pistons and troubleshoot your brake...
The piston isn't supposed to pull all the way back into the bore...
Noise can come from lots of things... improperly torqued hardware, play in the hubs, loose spokes, glazed pads, pads/rotors that aren't bedded, etc.