Well the noise when from bad to almost a crash, I hit the brakes lightly at about 40 mph and the front brakes locked up I wouldn't have beleved it but the thing almost fliped, it stood straight up on the front wheels, anyone have a clue what is going on with this thing, pain isn't my favorite thing.

 

Did you change anything???

A friend of mine bought a 96 sp500 new....He's complained about the noisy brakes since day one....Might have to let him know about the o-ring trick.

 

Dcroc

 

OOPS! hit too many buttons at once.
dcroc, sounds like your have a problem with your proportioning valve or some sort of blockage to the rear brakes, this sounds like it could get you into trouble fast. I suggest taking a real good look at what you did back there, maybe get a buddy to give a second set of eyes on the situation.

 

Well just got through checking everything out, it's getting even brake pressure front and back, the pads are good and not glazed, no broken bolts, and the rotors are still in good shape and not wharped, took it for a test drive and still plenty of noise at applacation, but haven't had the locking up problem as of yet, maybe I need to get some body armor or have a direct line to life flite to keep riding this thing.

 

Try adjusting the rear brake. It may help your nosedive problem.

SurferSam

 

I don't think it is the rear brakes, I am no expert but it acted like the front brake locked up because the rear wheels came completely off the ground, kind of put me up on the tank. I checked the rear brake and it is ajusted and has free play. I'm stumped!!!!!!!

 

dcroc,
Considering you just had new pads installed, this may have uncovered another brake system problem. With worn pads, the quad's braking probably wasn't that good and another problem wasn't evident.

I took this out of a service manual. One of these might help:

Sympton: BRAKE LOCKING
Check:Incorrect brake fluidPlugged passages in master cylinderIncorrect front brake adjustmentCaliper piston and/or brake adjustmentWarped brake disk


Some things to try:
Jack up the quad completely off the ground, turn each wheel and inspect for brake adjustment and possible disk warpage. Theoretically, the brake pads should barely drag their respective disks and the amount of drag should be the same for each wheel. Next, remove the front tires so you can see the front brake disks, start the quad, put it in gear (and AWD), and give it a little throttle to turn the wheels to about 10 mph. Listen and look for any potential problems. Very lightly, apply the brakes. The wheel that stops turning first may have the possible disk warpage or "too tight" brake adjustment. Put the quad back in neutral, and turn the suspect wheel by hand while applying light brake. If you feel resistance only during part of each revolution, it may be a warped disk. Otherwise, check the brake adjustment.

Uneven hydraulic pressure from the master cylinder will cause one wheel to get way too much pressure and the other wheel to not get enough brake pressure. If you find one wheel stops abruptly while the other has little drag, suspect hydraulic problems (ie. brake line, master cylinder, caliper).

This is enough to get you started on troubleshooting the problem. Post what you find and maybe we can narrow down the problem.

SurferSam

 

Well Surfer Sam, I tryed all that you had on your post, jacked it up and tried the power on deal, with slight brake pressure and still got noise from the rear brakes but no lock up, the pads are the correct ones for my model, checked the rotors and no discoloration and are not warped, pads are adjusted correctly, have always used Dot 3 fluid. the calipers are free and not sticking. Put it back together and test rode it with no lockup but still making plenty of noise, I don't know what to do short of replacing the entire brake sys. I have never seen anything like this before. Called four different dealers in the area and they have heard about the noise in the older models like mine but not about the front locking up like this one did, what's worse I can't make it do it again, kind of scary isn't it. Any other suggestions?

 

dcroc,

One good thing about the brake system: it's all mechanical- no electrical gremlins to chase. If your rotors are good and the calipers are in good working order, you may have had a temporary brake system clog to one of the wheels. The dealer may have added brake fluid that had trash in it. A piece of trash could have temporarily clogged one of the brake circuits causing all of the hydraulic pressure to be directed to only one or two calipers instead of all three. That's a lotta hydraulics to just one caliper. If it's trash in the system, you may have to go all the way to the extreme of disassembling the hydraulic components to clean and flush the system.

Chasing gremlins and their intermittent chaos is the hardest. I wish I could give you a clear cut solution. Hope this helps.