I couldn't have said it better.

 

That is **REALLY* bad bearings if it caused the disk to angle and pushes the cailper back in. Seems like you woud hear them or feel them before it got anywhere near that bad.

If you ride in lots of water then yes repacking often is necessary. Not only on a Cat, but any quad.

-jeff b.

 

There obviously has to have movement or this to happen.
How much movement is going to be based on piston size, and master cylinder bore size.

Another thing that can multiply this is the fact that the arctic cat uses one master cylinder to operate THREE calipers. From what I understand, there is actually FOUR calipers on the Arctic cat. That is a lot of volume for one master cylinder. Even a warped rotor can have a hand in this soft pull equation. Or how about warped rotors, and two slightly loose wheel bearings.
So to answer your statement that you would have to have a (really) bad wheel bearing isn’t 100% factual, but just one reason for this.

There are to many items involved in this simple action.
My previous statement was to help understand the basic principle, not to make every one on this forum a certified Mechanic.

 

Thanks for all the repies to this post. I would have never suspected the wheel bearings were the problem. I have not had the time to check, but since I have never looked at the bearings (2200 miles), it warrants looking into. I ride mostly old logging roads, lots of mud/water. I checked the price, about $52 CDN/bearing.
Do you have to take the hub right off to change the bearings, or do they come out just by removing the hub nut?

 

I believe you have to remove the hub.There are two seals one inside one outside.

 

mine has done that from day one i only have 280 miles on it now. the dealership said it was the master cylinder so they replaced it. but it still happens.

 

My 2000 300 has 2800 miles on it & I've changed all wheel bearings once at about 2200, I do ride a lot of mud, but my brakes have always been as decribed, they have never improved after a bearing change??

 

If the rotor is deflecting any amount, or warped, the piston will move back into the caliper. If there is any play in axle, and the calipers are fixed to the frame, you will move the piston back. If the attach points, or calipers are vibrating back and forth while riding, you will move the piston back. If the wheel assembly flexes in a corner, you will move the caliper.

The first thing I would do is make sure there are none of the above going on... Which I am sure a little of all is happening.

Second,,,, Maybe I should start marketing a second master cylinder to operate the rear brakes... This would reduce the amount of fluid to be divided up....

Maybe you guys should ship me your bikes to test and diagnose for repairs... I figure it will take a hunting season to decide what is causing this grief..

 

Ok,, Here is a perfect example. This just happened today.. Four wheel disk brake system.. Customer had damaged a wheel jumping a curb. The different wheel is what made me look farther into the complaint of a soft brake pedal.. Pressure>>>> The brake pad wore a small pit into the brake anchor.. I measured the axle run out.... Guess what,,,, thirty thousands of run out... After the pad was unable to shift side to side, it pushed the piston back making a soft pedal..

Have fun in your detective work....

 

i know this is an old thread but i have to say that this is so common on Polaris ATVs and UTVs THey all eat bearings and exactly what WearyWonderer explained. A disc that doesnt maintain its position in the caliper causes the piston and pads to need excess travel before the brakes actually clamp tight. The master cylinder only moves so much fluid. Couple that with old worn rotors that are worn unevenly and thats alot of gap to make up. Then you have either 3 or 4 calipers depending on the model adding to the equation