Bicycle Mechanics - Brakes are screaming!!

I have a 07 Gary Fisher Wahoo, not even a year old. I have never had a problem with the brakes ,not even 2 days ago, all of a sudden tonight, im getting the bike ready to sell, and I take it for a ride and the brakes are screaming when i hit them. they are v brakes not disc, What would cause this all of a sudden?And on both front and back. FYI I haven't used any solvents or cleaners of any kind on the rims. Is there a quick fix for this. I hate now to have some one come test ride the bike and blow out there ear drums.

I've had a lot of success eliminating v-brake squeal with a brake booster. It's a big horseshoe shaped piece of metal that goes in front of the calipers.

I use this on my old Trek antelope which has Alivio V-brakes with koolstop pads that still squeal in front without it. It says it is for rear brakes but it fits and works on the front too which is where I have it. I had a similar problem on my friend's Trek 820 with the same solution.

http://www.nashbar.com/profile.cfm?sku=11615

toe in the brake pads.

toe in the brake pads.

Please explain that to me. Sorry If its a dumb ? Thats why im here.

Taken from the Park Tool website.
http://www.parktool.com/repair/readhowto.asp?id=19

"Pad Toeing:This is the setting of pad angle as it touches the rim. Toeing refers to setting the pad so the pad's front edge strikes first, which tends to reduce squeal during braking. Caliper arms tend to have play in the pivots and the arms flex when the brake is applied. This may cause squealing in the brake pads. It is simplest to first ride the bike and see if the brakes squeal. http://www.parktool.com/images_inc/repair_help/pad_toe_line.jpg Front of pad strikes rim first for "toe".
Most models of cantilever calipers use a "smooth stud brake pad." The brake pad is fitted with a non-threaded stud. The stud fits into a hole in a bolt head that secures to the caliper arm with a series of convex and concave washer and spacers. This system allows the pad face to adjusted to correct positions described above. Generally, it is easiest to adjust brake pads after the caliper arms are correctly positioned. The brake pads may prevent this. Loosen brake pad-fixing nuts on both sides of cantilever and lubricate threads, curved washers and washer-to-arm contact points."

It's kind of a pain in the behind on V brakes. You loosen the allen bolts or whatever that hold the shoes to the brake arms, and make the front of the shoe touch the rim before the rear. What happens is the whole shoe touches the rim at once, and begins quickly vibrating front to back. The brake grips the rim, flexes, and then lets go over and over . The vibration is heard as a squeal. A little hard to explain, hehe. With the shoes toed in, the vibration is stopped and the brakes are once again silent.,,,,BD

At least yours are adjustable, I just had to bend my old vintage brake arms to achieve the same effect.;)

beat me to it, lol.,,,,BD

Good explanation though BD :D

Thanks Guys, and or ladies, I will try to fix it tomorrow when I get home tomorrow.