car377@drutx.UUCP (RogersCA) (10/14/86)
My newly installed disc brake pads cause a raucous and embarrassing squeal when light brake pressure is applied. This noise doesn't seem to be going away as the pads begin to wear. Anyone know of a good way to stop this? (If this is another "old" item on the net, please send e-mail). Thanks in advance! Chuck Rogers @ ATT-ISL, Denver
mojo@mp-mojo.UUCP (Mojo Jones) (10/17/86)
From: car377@drutx.UUCP (RogersCA) > My newly installed disc brake pads cause a raucous and embarrassing > squeal when light brake pressure is applied. This noise doesn't > seem to be going away as the pads begin to wear. Anyone know of > a good way to stop this? (If this is another "old" item on the > net, please send e-mail). Thanks in advance! > > Chuck Rogers @ ATT-ISL, Denver The brakes on my Yamaha Maxim-X have been driving me to distraction. I tried using some goo from the auto parts store that is supposed to quiet disk brakes and it work great! For about two weeks. Then it was back to squeeeeeal. I could use a few tips myself. Mojo ... Morris Jones, MicroPro Int'l Corp., Product Development Northern Calif. Motorcycle Safety Council, MSF Instructor {lll-crg,ptsfa,dual,well,pyramid}!micropro!mp-mojo!mojo Not the opinion of MicroPro! Democracy: The bludgeoning of the people by the people for the people. -- John Galt
ron@hpfcdc.HP.COM (Ron Miller x3260) (10/20/86)
Re: brake squeal
I recall reading an article or two about the subject.
The source of the noise is mechanical oscillation of some sort. The two
usual places for vibration to take place is either the brake pads or
the rotor discs.
One fix is to place some sort of damping material behind the brake
pads (not between pad and rotor) which prevents vibration of the
pad. This material is usually a very viscous fluid which is compatible
with brake materials. (I thing this is the stuff which one netter tried)
The other thing to try is the rotor itself. One of the production changes
of a popular bike (I don't remember which one) was to add a thin paper
gasket between the brake rotor and the wheel. This effectively changed
the oscillation characteristic of the rotor and killed off the squeal.
There are undoubtedly more fixes out there but these are 2 I've heard of.
Good Luck !
Ron Miller
{ihnp4, hplabs}hpfcla!ron
carey@uiucdcs.cs.uiuc.edu (10/22/86)
One book I was reading said that you should clean the disks,
sometimes there is a residue left on them from the pads.
With new pads, the noise would presumably be worse until a
small groove wore in at the spots were the extra material is.
I have no idea if this has any basis in reality.
Speaking of brakes, my front brake on my Honda CB550F is
stuck. My girlfriend had a similar problem with a sticking
front brake and we tried lots of things to try and fix it.
I wonder if the problem is "inside" the brakes -- perhaps
some corrosion (rust) on the pistons that close the pads?
(I don't know the correct terminology)
Has anyone else had a similar problem? If so, what was the
solution? If the problem is where I think it might be, can
the brake be dissasembled to that point, cleaned and reassembled?
How difficult is it to do? Or does the brake need to be replaced?
Any help would be greatly appreciated.
-John Carey
-- {ihnp4,convex,pur-ee}!uiucdcs!carey carey%uiuc@csnet-relay.arpa
carey@uiucdcs.CS.UIUC.EDUroman@sigma.UUCP (10/23/86)
I had a similar problem on my Yamaha XS650B. I was successful in completely disassembling, cleaning and rebuilding the caliper. It's a pain, but it can be done. If you're not used to working on brakes, and you've got a few dollars to spend on something your life depends on, buy a new caliper. For those of you out there who haven't been blessed with this sort of problem yet, go look in your brake fluid reservoir. Brake fluid getting a little dark, hmmm? Flush the system! It's cheaper/easier than fixing the caliper after that gunk in there jams it up.
cabbie@chinet.UUCP (Richard Andrews) (10/25/86)
In article <8800042@uiucdcs> carey@uiucdcs.cs.uiuc.edu writes: > > >Speaking of brakes, my front brake on my Honda CB550F is >stuck. My girlfriend had a similar problem with a sticking >front brake and we tried lots of things to try and fix it. >I wonder if the problem is "inside" the brakes -- perhaps >some corrosion (rust) on the pistons that close the pads? >(I don't know the correct terminology) >Has anyone else had a similar problem? If so, what was the >solution? If the problem is where I think it might be, can >the brake be dissasembled to that point, cleaned and reassembled? >How difficult is it to do? Or does the brake need to be replaced? >Any help would be greatly appreciated. > > You bet the problem is inside! The pistons are stuck in the caliper. I suggest you get the service manual out and disassemble the front caliper(s). The easy way to get the pistons out is to remove the caliper from the front wheel and apply the brake and keep doing it until the piston is pushed out of the caliper. This is a common problem on corvettes and can happen on most any other car. If the piston is pitted, replace it. If the caliper is too then you will probably have to replace it also. Rich Andrews ...ihnp4!chinet!cabbie
ahn@houem.UUCP (Au H. Nguyen) (10/27/86)
> The easy way to get the pistons out is to remove the > caliper from the front wheel and apply the brake and keep doing it > until the piston is pushed out of the caliper. Wouldn't that make for brake fluid squirting all over the place? I thought you're supposed to disconnect the caliper from the brake line, drain it, and use compressed air to force the piston out? Silly me! Au ihnp4!houem!ahn
allen@uicsrd.CSRD.UIUC.EDU (10/27/86)
You guys make rebuilding a caliper sound like a big deal. Once you get the piston out, all you have to do (usually) is clean all the parts, replace the rubber seals, put the piston back in the caliper and bolt the thing back on.
cabbie@chinet.UUCP (Richard Andrews) (10/28/86)
In article <678@houem.UUCP> ahn@houem.UUCP (Au H. Nguyen) writes: >> The easy way to get the pistons out is to remove the >> caliper from the front wheel and apply the brake and keep doing it >> until the piston is pushed out of the caliper. > >Wouldn't that make for brake fluid squirting all over the place? I thought >you're supposed to disconnect the caliper from the brake line, drain it, and >use compressed air to force the piston out? Silly me! > > Au ihnp4!houem!ahn Well that is what they tell you to do in the books but if the piston is really stuck then compressed air will not work and if it does let go the piston usually goes flying across the work area and is ruined. I have seen several accidents from using the compressed air method. Secondly the caliper does not require removal from the car or bike just to get the piston out(with all of the associated grief with brake lines etc.). I have used this method for a long time and have found that it works quite well. Rich Andrews ...ihnp4!chinet!cabbie Don't knock it until you have tried it!
car377@drutx.UUCP (RogersCA) (10/29/86)
> > You guys make rebuilding a caliper sound like a big deal. Once you get the > piston out, all you have to do (usually) is clean all the parts, replace the > rubber seals, put the piston back in the caliper and bolt the thing back on. > > allen@uicsrd.UUCP For those individuals with no mechanical training or innate mechanical ability, any sort of mechanical repair is a "big deal". There is also a subgroup of professional mechanics who consider themselves to be competent technicians, but who are in fact absolutely incompetent and should not be permitted anywhere near mechanical devices. I am not a trained mechanic, but like many others, I learned a lot by trial and error, by using shop manuals, and by observing the efforts of others. I have "rebuilt" (disassembled, cleaned, replaced seals) calipers many times, and I have done so in total ignorance of whether or not the cylinder/piston machine tolerances were correct or not. In some cases, the walls of the cylinders or pistons were worn and pitted some, but I figured, "what the heck, it'll probably work out OK." There was also a time when I thought that torque wrenches were unnecessary, that all brake fluid is alike, that seals can be reused if they appear undamaged, that you can use an ice pick and a ball peen hammer to remove a piston circlip, etc., etc. Fortunately for me, all my brake work has been done on cars, not bikes, and I always had the other three wheels to stop with if one of my caliper "rebuilds" didn't pan out. I take a different attitude with my bike, since I can easily kill myself if I don't do things right on any one component. In any case, the "(usually)" you mention above is the operative term here. If your typical mechanical experience is so effortless, then you are either extraordinarily lucky, or you are understating the extent of your mechanical training and abilities. Many of us have stripped too many bolts, scarred too many machined surfaces, ended up with too many extra parts, observed too many after-the-job leaks, and patched up too many cuts and bruises (to the accompaniment of too many magic words) to consider a lot of "routine" mechanical repairs to be "no big deal". On the positive side, a lot of us do our own work anyway because it is fun, or it satisfies some inner desire to see how things really work, or we can't find a mechanic who appears to be sufficiently trained to be trusted with our machines. Chuck Rogers @ ATT-ISL, Denver