The "usual" bad rear brake master cylinder
Ok, after reading a bunch of posts on this exact problem (rear brake cylinder going bad on older Cats), I'm not sure what to do here. My wife's '04 400 4x4 auto has followed what seems to be the normal path to rear master failure. I took the machine to our local atv/dirt bike expert (where I have way more confidence that the local Cat dealer...) and he found the problem to be a bad master cylinder. He tried to order a rebuild kit but low and behold, Cat doesn't offer a rebuild kit. What's up with that? So now it's either buy a whole NEW m/c (for big bucks - like over $200), or try to cob something up. I'm headed off to Napa to see if they can match up these 'cups' that are actually the problem but can't be purchased individually from Cat.
I've read where some folks have replaced the entire rear brake system with parts from later year 500's with success. I'm up for that if that is a viable alternative to buying another '04 cylinder that will just go bad again.
Any tips or experience in this area that I can use to get us back on the trail? Bear???