My son and I were riding our '03 Wolverine last week when the rear brake suddenly stopped working. Both the foot and hand lever work (when you pull either, the other moves), and I don't seen anything obviously (at least to me) damaged. The rear brakes don't grab at all, but when I took out the pads (which are thin, but not completely gone), the piston (or whatever it's called) that pushes the brake pads does come out a bit when you step on the brake. I'm not sure it comes out as much as it should. The rear brake rotor isn't perfectly flat - it is slightly bowl-shaped - I don't remember if it was this way before. I don't see any obvous sign of having hit a rock, but that is certainly possible. It was a very hot day, and we rode through creeks numerous times, as well as over rocky terrain. One guy I spoke with guessed that the rotor may have warped from getting hot and then being submerged in cold water - does this sound likely?

I've ordered a replacement rotor (Tusk stainless), and a set of brake pads, but I'm concerned that these may not really be the main problem. It seems odd that they would suddenly stop working. My son was riding it at the time, so I don't know if anything unusual happened. He said he was having some trouble shifting, and I noticed that the quad will now start when it is in gear (which it wouldn't do before - it always had to be in neutral). I don't know if this is related to the brake issue or not.

Just as background, we bought the quad a few months ago, but I don't think the previous owner had used it much (he'd had some medical problems, so I think it sat in a shed for a year or more). He'd recently had is serviced ("everything checked") by a dealer. He did this because it wouldn't start - probably had gas carmelized in the carberator from sitting so long. It looks nearly new, and prior to this has run fine - the only problem being somewhat difficult shifting at times.

I spilled a few drops of the brake fluid when I was removng the brake pads (loosened the wrong bolt). I don't know how or where to check for sufficient fluid - I'm going to trace the brake line and see if I can figure it out. I noticed a couple of rubber capped "nipples" on the brake mechanism - are these for adding/bleading fluid, or maybe grease or something?

Sorry if this is a rookie question, but we're definately rookies when it comes to mechanical work on ATVs. Any suggestions about what could cause this will be much appreciated.

Thanks

Doug

 

Doug,
Did you get this figured out? I'm wondering if the parking brake is on or stuck. Check that and take a look.

The rear reservior for the brake fluid should be on the left side of the quad (as your sitting on it).

While you have the caliper off, lube the slide pins. There's not much grease on them from the factory and lubing them will help the caliper float back and forth like it's suposed to.

 

Glen, Thanks for the advice - much appreciated.

I wound up changing the rotor (which was pretty bent) and putting on new brake pads. It seems much better now, but I think the new pads are rubbing against the new rotor slightly - is this normal? It seems like I should loosen the brakes a little somehow to leave a little more space between the pads and the rotor, but maybe that's not necessary. Are the brakes adjustable in this way? Do I need to worry about this?

Thanks again.

Doug

 

Doug,

The new pads should really rub at all. When installing the new pads, did you push the piston back into the caliper? If not use a c-clamp to do so. Make sure you remove the cap to the fluid reservior to leat the pressure escape. The face of the piston should be about even with the body of the caliper. I had an issue with pushing the piston back all the way. Turns out, the e-brake mechanism was holding things up. Just popped that off, and I was good to go. Once the pads were installed and the caliper was mounted, I hooked up the e-brake again.

One thing to watch on these calipers is the sliders. Even with boots, they get gummed up and rust a bit. That's all it takes to keep the caliper from working properly. Ever few rides, it's a good idea to lube the pins with a little waterproof grease. That should keep things moving freely.