I have a 16 Uforce 800 EPS.  The brakes have always been soft.  I tried bleeding them and had several air bubbles come out.  But now they seem even worse. The pedal has very little resistance to it.  I have flushed and bled the brakes until I can't get any air out at all, but still can't get the pedal solid.  The calipers do move , but they have a very small amount of travel. 
Starting to think I have a bad master cylinder.  Anyone have that go bad in one of these machines? I know the rubber seal that goes on the master cylinder cap doesn't fit well and deforms easily. 

[2015 Z Force 800 53/Trail EPS]

Yours won't be the first with a bad master cylinder. If you know all the air is out without question, then it has to be. I had air in mine and when I bleed the brakes I went one pump too much and pulled air in and that took a while to work down to the calipers. Thought I would never get there. Think a power bleeder would be the answer cause any more then three pumps when full will do it. They are solid now but didn't start that way. I also wend to a different pad up front which made the biggest difference.

Mighty vac works good for brakes. I'm thinking master cylinder too. Is there a seal kit.

Yeah a couple weeks ago I bleed my system a second time.  I had a real firm pedal that didn't go to the floor.  The machine sat in the barn for 8 or 9 days before I took it out again and the brakes are spongy again.  Not as bad as before, but spongy!

[2015 Z Force 800 53/Trail EPS]

Yeah a couple weeks ago I bleed my system a second time.  I had a real firm pedal that didn't go to the floor.  The machine sat in the barn for 8 or 9 days before I took it out again and the brakes are spongy again.  Not as bad as before, but spongy!

Check to make sure the push-rod isn't too tight. It needs enough play to allow the master's piston to come all the way back. Many have found then set too tight.

Sounds like a leak. Not a bad one, but I would check all the fittings.

Sounds like a leak. Not a bad one, but I would check all the fittings.

Well, I made a trip out to my rural property today to go over the brake system.  What I found is the pin that attaches the brake pedal to mater cylinder rod was missing.  I found a 1/4" bolt to use for now and the brakes are working fine.

On a (hopefully) related note: I came from a Polaris Rzr 570 and the only thing that was better was the brakes! It always gave me change back on that dime....ZForce Im steadily putting quarters in it when I need to stop suddenly.

[2015 Z Force 800 53/Trail EPS]

Mine are finally decent. It took upgraded pads and a fluid change-out to synthetic which also took some air out of the system.

I just replaced the rear pads to EBC sintered, the factory ones were worn to the metal in 800 miles.  Changed the fluid, adjusted everything, and they are better but the pedal is still a little soft.  I think the calipers and master cylinder in these things are just weak and arent really up to the task of stopping a 1000 pound vehicle quickly.

[2015 Z Force 800 53/Trail EPS]

I just replaced the rear pads to EBC sintered, the factory ones were worn to the metal in 800 miles.  Changed the fluid, adjusted everything, and they are better but the pedal is still a little soft.  I think the calipers and master cylinder in these things are just weak and arent really up to the task of stopping a 1000 pound vehicle quickly.

I think your right but check that the push rod on the master has play at the top. The master's piston has to come all the way out to the stop to open the return to the reservoirs. I also found it a bitch to get all the air out. I think I'll invest in a small power bleeder next time.