John deere 2940 PTO problem

I recently bought a Hesston 1160 windrower for my John deere 2940. I have everything ready and just when I started cutting the PTO stopped rotating.The power take-off no longer rotates if it has any load.Everything else on the tractor works great.All filters are new.Is there a quick fix that can fix the PTO problem?This is quite urgent.

Thanks in advance,

It is the clutch of the power take-off.Either it is burned or the piston seals.Either way you have to take John deere 2940 apart.