I have a leaking master cylinger on the right hand side of my 89 4X6 Big Boss. The Polaris manual shows a breakdown of the left hand mastercylinder but not the right. It does not mention the repairs are identical on both sides but it also does not mention the right is not rebuildable. My Polaris dealer shows the same information on his micro fiche, left hand parts shown but not right. No one so far has been able to tell me if I can rebuild the right hand one. My next step would be to pull both apart and see what's up. Also the manual mentions a repair tool used to insert the piston and seals into the cylinger, can this be done without the tool? Is there anyone out there that knows some information on the master cylinders of this aging beast. It's gotta be the best ATV i"ve ever owned and it still runs great - except for the right hand brake problems.

 

In addition to your search for the answer to your question (sorry, can’t help you there) you may also want to do a web search for a used master cylinder. Use ATV parts for your search phrase and you’ll come up with a few that sell used stuff, like bone yards for cars. Might be worth a shot. Good Luck!

 

Back when I had my 88 Trail Bosses, I broke my Left hand brake assy. I replaced it with a 93 unit, much better handles and braking power.

So what I would look at is a newer year of 4x6, 6x6's to see what they offer for the right hand side brake assy.

I know this doesnt apply to fixing, rebuilding what U got but I really did find that the new brake assys are much better.

Now with that stated, on my 96 ATV's, I went and replaced them with 98 assy cause they were even better then the early 90-96 units. I am not sure of what years they changed, but I know my 96 was like the mid 90 units and my 98 is newer then that. Important part is that they had the same hose fittings and fit on my handle bars.