I just bought a 2018 cforce 400 2up.  The other day i was out for a run and i was doing aroung 60 km/h.  I had to brake hard and, use the foot brake. Ii heard a loud, repeating almost like cracking or clicking noise.  hard to tell if it was coming from drive train or brakes.  Only when braking hard at higher speeds.  This is the first quad i have owned.  Any info?  It would be greatly appreciated.  I am somewhat of a newbie to the atv world. 

[2015 Z Force 800 53/Trail EPS]

Many times when braking hard on a quad one tire or another will skip as it looses traction and jolts the drive train one direction then the other when it ends it's skip. This sounds like lots of loose drivetrain parts. Happens mostly on rough surfaces with some loose stuff during hard braking. Could this be what you heard? Try doing the same thing except on the smooth road. If it still does it you might be having a brake problem.