My rear brakes continue to get softer and I run out of adjustment on them. I know what the problem is, the sealed drum gets filled with water/mud. However, the pads do not seem to wear down. They look like they are about stock thickness still. Here's my question, could the brake drum be wearing down instead of the brake pad? Anybody know the inside diameter of a new/stock brake drum?

I know mud will eat up brakes, but wouldn't it take out the brake pad vs the drum?

 

Same problem with mine. It's not the brakes wearing or the drum wearing, it's just that little bit of lube added as soon as you go through the first puddle or mudhole. It doesn't take much moisture to make the drum brakes slip.

Mine worked great when new and for the first year or two, but once the rear brake system was opened up, neither I nor the dealer could get it to stay sealed like new again. I pretty much rebuild the rear brake after every ride - gave up on hoping that it stays sealed and run it with the drain plug out - that way we can run it through flowing water whenever we cross a creek and clean out the mud.

 

Here's what I ended up doing:

I found a replacement seal from QuadBoss (about $35 shipped) and installed that. This seal is the one that is on the outside where the hub meets it. Then, I cleaned it out real well (again) and lubed it up at the two seal points (the new seal and where the casing meets the brake plate) with marine grade grease. Then, I moved the brake lever back one spline so I've got plenty of squeeze now in the hand brake and on the footh brake. Hoping this will keep it stopping.