I have heard of a worn out/failed harmonic balancer causing broken cranks. I don't know if that engine has one or not but if it does I'd take a close look at it and if in doubt just replace it.
You're probably right but I was thinking if the nut fell off 4" might be about the distance the rod could travel through the piston before it quit blocking the hole and let fluid bypass. That would likely only happen once as the rod probably wouldn't line up with the hole to go back in the piston.
JIS and JIC have different threads as well as different tapers so they won't screw together short of forcing them. Maybe a picture of the fittings in question would help identify the problem.
Have you checked to see if you are getting 12 volts at the valve when the switch is pressed?
If you are and it still doesn't work check the resistance of the coils on the valve. They should be the same resistance. Why does a grapple need a circuit board?
I think that's likely what you'll have to do. The shape of the tank makes it about impossible to fish any debris out. I had the tank out of my BX22 years ago to fix tank port leaks. I don't remember it being a terrible job.
Looked like chrome solution but sure wasn't done anything like the shop I worked at 40 years ago. The rod would have been stripped of the old chrome and when rechromed it would come out with a frosted looking coating that would then be polished or ground. Tear down and reassembly all done on a...
About a 98% chance you have a quick couple unseated. Disconnect and reconnect them. It's not always obvious which one it is. Do it with the loader on the ground and relieve the pressure first. If it's not that check that your linkage is giving full range of stroke on the valve spool.
You can't just plug them. You say you removed 3 hoses but that they didn't install a power beyond bushing? What was the 3rd hose connected to then? I'm guessing they had the power beyond and tank hoses reversed, but only a guess. Hopefully someone with the same tractor can show the original...