640 tailgate problem

[muduc]

Problems with the tailgate opening on my NH 640 round baler it is stored in my machine shed all winter...it was blown off completely and oiled the chains and greased it before winter storage...ready to bale some first cut alfalfa...hooked up to my JI Case 970 & pulled out of the barn...flipped on the pto it was good, always cycle the tailgate up and down before starting the first bale...tractor grunts but the tailgate does not even budge...so checked my remote hookups all was right...even switched to other set of remotes..same problem...thought well maybe its the tractor...went back to the wheel rake Kuhn 10 wheeler V rake...hooked up...it raises up and down on both sets of remotes fine at idle....so I am thinking not tractor..but baler...so I thought the safety valve that you engage when tailgate is up in the air...uncoupled the pressure side of cylinder on the back side of safety valve and shot fluid everywhere when I popped the remote lever..so safety valve is ruled out...I think somehow the big latches that drop on the tailgate pins are stuck down or the packing(O-rings in a cylinder or both cylinders) let go and the fluid is just by passing and pushing the tailgate up....HELP!! Anything I am missing here?

 

[old]

Had that happen on my NH850 round baler a few years back. The cylinder where getting bad and leaking inside so the tail gate would start to open as you baled. Rebuilt them both and all has been well. If the cylinder are like the on on the 850 they are not fun to take apart since you have to push down on the end cap part to get to the locking ring. I have the exploded view some place on this desk

 

[rrlund]

And you're absolutely positive that it's not one of the male tips at the couplers?

 

[muduc]

Yes sir you nailed it...I had pressure on the return side male tip...smacked it on the side of the baler and worked like a charm!