4500 ford backhoe hydraulic problem

Sometimes when I use the lever that drags the front boom and bucket back, it just stops moving , it will work to push back in the opposite direction. I sit there and jiggle the lever back and for a few minutes and the boom will finally take off as usual. I noticed it usually happens after I have let that boom drop fast when I am in a hurry . It seems like the gravity of the boom falling some way out runs the fluid that pushes the boom down and causes it to freeze .

It could just be the cylinder's piston seals are shot. On my 4500 the front bucket curl pistons did that and rebuilding the cylinders was the only thing that fixed it. On that repair, just remember one thing; when you knock the pin out holding the cylinder in, don't have your hand under the cylinder. You'll know why if you do.

Thanks JF , I have put new seals in that cylinder once or twice for leaks over the years and best I can remember it didn't affect the other problem . Both the boom cylinders are leaking again and so it is worth a try because they need new seals any way. That reminds me of another thing I never did know , sometimes a leak can be helped by tightening the nut on the end that compresses the seals . Problem is I never did know how tight that should be . I don't have the proper wrench but I use a big pipe wrench to snug it up good but afraid to tighten to much. Is their a torque spec or something for that ? I can estimate the inch lbs of torque by multiplying the length of the pipe wrench by the amount of a weight I slide on the handle. I know the torque depends on the size cylinder and I forget the dia. of the 2 boom cylinders . I think they call that a 7500 attachment used on the 4500 backhoe. That is a very good safety tip you gave and I hope others read that . The cylinder is very heavy especially when full of fluid. Also if their is a little air in the cylinder or hoses a hard kickback can occur when knocking the first pin out if you forget to disconnect the hoses first.

When I get cylinder leaks at the rods I just tighten enough to stop the leak and not more. The 750 hoe is the largest one available for the 4500.

Worn O-rings in the control unit?

Seems I had a similar problem, on my 4500 a few years ago. one of the O-rings was smashed.

For any of you guys with 4500's, I've pulled the loader off of mine to install a lighter Farm Hand quick attach loader. All I do with it is move round bales of hay, pull a rake or wagon and clear roads in winter.
I've got a good set of two handle controls along with non leaking lift and tilt cylinders. Main frame has been welded but still looks ok, loader boom is pretty much junk, didn't get the hoe with tractor when I bought it.
If any one needs parts let me know.

Thanks Plowjockey ,
That makes sense to me because an o ring gets its seal when the fluid pressure moves it against the space it is sealing . If there is a problem from wear or something the fluid may just slide by the o ring and not make it move every time .Also when I have the boom dropping fast and let off on the lever I can see how that could put a lot of back pressure on the o ring and cause it decide to act up for a while . Best I can remember that valve is not to hard to open up . I had it out one time but I didnt really know to look for . I was mostly looking for some thing obvious and for trash . I might not have noticed a flat shaped o ring as a problem . I hope I can get o rings for that. Do you know where ?