3 point hitch Woes. I'm stumped!

[Kernopelli]

Was doing some dirt work for a buddy of mine last week. You know the kind, he says "20 minutes with your box blade" and I spend 2 hours digging root balls out before I can even start using the BB.
Anyway, everything was working fine and suddenly, no lift at the 3PH. Loader works fine, ran the tractor about an hour this weekend and noticed the lift arms were up. I checked it out and they wouldn't lift with weight on them but I could drop them and they would rise as long as there was little/no weight on them. When they were up, they would hold pressure and lock in place until you lowered them with the lever. Ive got pressure ( flow anyway..I haven't put a gauge on it yet) to the 3ph, filter screen clean, full oil level. I assumed it was either a linkage problem (it isn't), a relief stuck partially open or something in the control valve. I disassembled the relief valve at the 3ph and everything appears to be OK. I took the top off the Diff housing and checked the 3ph piston and the o rings look good, no junk etc. I took the control valve off and disassembled it and found a small piece of metal in one of the spools...it looked like it was probably holding the valve partially open. I felt satisfied I had found the problem but upon reassembly, it still doesn't work. The arms won't even lift with no weight on them as before. When I move the control valve to "lift" it pulls the engine down slightly like when there is high pressure and a relief opens somewhere.
I have a loader and have the 3 PH plumbed in line with it.
Any ideas???

 

[Kernopelli]

OK, Just went out and put a gauge on the port for the 3ph and had pressure when I put the lever to lift but it would fluctuate between only 1200-1450 psi. That should be way more than enough to lift the arms though. I had set my loader relief valve (seperate from the joystick, it is in line between the loader valve and the 3 ph) to about 1500psi when I put it on but just now I tried turning that relief in/out did not produce any pressure difference at the 3ph gauge. When I move the lever to lower the 3ph, the gauge does fall to zero.
Now what????

 

[Kernopelli]

Well, problem solved. It appears the piece of junk in the control valve was the problem. However, I had inadvertently assembled the flow control backwards when putting everything back together. It contains a ball/spring setup and I put the ball in first, which blocked the orifice that flows hyd fluid to the piston. Swapped it around and everything is working great.....still need to get the sheet metal back on but I am glad to have it back up and running correctly.

 

[Egon]

Seemed like something I would do. Good you got it figured out!

I always think about taking pictures as I go along but come time they are forgotten or the hands are too dirty to handle the camera.

 

[Kernopelli]

I always think about taking pictures as I go along but come time they are forgotten or the hands are too dirty to handle the camera.

Same here. The flow control was the only item in my manual that didn't have a schematic. Then again, if I had been paying closer attention when I tore it down, I wouldn't have even noticed there wasn't one in the manual.

 

[3RRL]

Don't you just hate it when that happens?
I can't tell you how many times I've done what you did, re-assemble out of order like that or forgetting a tiny (but important) part. It's just annoying and the biggest problem is I end up breaking something disassembling it again to put it together right.
Glad you got it all working again.