Brake bleeding twice in two months

[ZX11]

I took my bike out today for a test ride after some maintenance. It has been sitting for two weeks. I had no rear braking. I don't use it much since I am an old street rider so it could have been getting that way for awhile.

I bleed it and the braking returned. The thing is that I got the bike two months ago with no braking action on the rear. I had to bleed it to fix it then also. Normally I go years without having to bleed a brake system. What is going on with my ATV? The front brakes haven't needed anything.

[yfzracer14]

Take your rear master cylinder cover off and poke a small hole in the rubber seal in the center. This will fix your problem. I had to do it to both of mine.