806 Hydraulic problem

Here is my problem. I've put my blade on for winter. My hydraulics are operating a single cylinder in the front of the tractor 2 hoses are run to the back. The first time I raised the blade it worked fine. I tried to lower the blade but there was no action. Check the hose connection to see if on had popped out all was fine. Take the tractor back to the shop and hooked up my other tractor to make sure it was not a cylinder problem, nope it worked. Checked fluid level was below full, topped off, no change. Went to archieves on YT mag and here is what I've done so far. Changed filter and oil(both oil anf filter did look good) and over filled the resevouir by 3 to 5 gallons of trans hydraulic fluid. I also took out pressure relief valve and took it apart and found a approx 1mm by 2mm piece of steel between what I would call the needle and seat? Put it back into the tractor started it up and let it run for 15-20 minutes then tried the hydaulics. I lifted the blade slightly(feathering the lever) which worked fine and it worked good when I let it down(feathering the lever).I thought all was great then I pull the lever back the blade lifted up nice and fast but then was locked into that position again. I swithed hoses from side to side on the back and left some oil out so the blade came back down but I had the same result just with the lever moving the opposite direction. I do have two sets of remotes on the back of the tractor but the one set of couplers need work or changing so I have not tried the other set of remotes. If it matters with this problem or not my pto works, steering is good, t/a is working, brakes work. Also when I work the lever back and forth when the blade is raised up it does make the engine work so I would think the pump is ok. I can make the blade move very very slightly(next to nothing). There is no squelling noise when I move the levers back and forth.

What should I look for now? Get the other set of couplers working at the back? New pressure relief valve?
Thanks Todd

Put new ends on the tractor problem solved.

So you're saying it's my hydraulic couplers at the back correct? Would you put new IH ones on or switch over to pioneer style?
Todd

the 806 should have pioneer ends on it,but since it does not does it have the old IH valves with teh levers on the side?
If it does I would be willing to bet that if you get someone to play with those levers while the other runs the lever it will start working.
I will agree with tractor vet,the problem would be solved the right way with new breakways.

It has the old IH valves with the flow shut offs on the top. I hate this system anyways for trying to hook up. I'll get some new ones.

Well they came with pioneer when new . Over time the springs that hold the ball closed go bad and will shut the flow off . Now it also could be the ends on the hose . So to save time replace both end on the tractor and the hose .

I had a problem once it really was madning at the time on my 806 couldnt raise hydrulics, a pebble was caught under the lever on floor and i thought i was moving the lever but all way through motion, popped it out and everything work fine again, that was my problem but check it out anyway.

Changed the couplers tonight started it up and like the Vet said "Problem solved"

Thank you