FEL sometimes wont lift?

[garcol]

Sometimes my loader wont lift, or is slow to lift with little power. Most times I can curl the bucket up to lock and this seems to get it working good again. Just the other day I went to lift my tiller and when I went to lift loader a bit higher it actually dropped down slowly while I operated the valve.
This has been this way for a while, but I dont recall it ever dropping like that. I also have a small backhoe and a grabble attached and all hydraulics seem to work very well, except the lift on the loader does this on occasion even with the bucket empty. The backhoe is now off.
My tractor is a small YM155d. I did replace the hoses to it last year, except for the hard lines. It has always bled down about 2 to 4 inches after actuating it but holds good there.
There is no sound from pressure relief when this happens.

With it dropping that way I feel it is time to get it fixed.

Is it possible I have some crud in the lines? How do I bleed those cylinders/lines out?

Thanks,
Gary

 

[marimus]

Have you checked your fluid levels? Might just need a top-up.

 

[kennyd]

The system is self-bleeding, so unless there is a leak on the suction side of your system(you would have foamy fluid) then air should not be the problem.

Since the loader is dropping before raising, I would suspect the valve is the problem, the load-check could be bad, or the spool is just worn beyond tolerance.

 

[Farmerford]

When curling bucket to lock to get the lift working again, do you have to hold the bucket valve against the stop for it to affect the bucket?

 

[J_J]

Gary,

I would put a gage in the circuit to check pressures. Just tee in a gage before the valve, and after the valve. Would only cost about $40.00. Like Kenny said, there are load checks in the valve, and the purpose of them is to prevent the load from shifting when the valve is actuated. I am thinking your valve is gummed up, and needs a good cleaning, or some 0-rings replaced, or the valve replaced. Just about all the valves leak to some degree, but to watch it drop is not a good thing. It sort of tells you about the integrity of the hydraulics. A good joystick valve can be had for about $200, from Surplus Hydraulics, or Northern tools.
You will not hear the reliefs if you are not fully extended or retracted, and if the relief are set at some pressure above your current operating pressure, you will never hear them. I had a lift pump that was only working at about half of it's rated pressure, and I could only lift about half the rated capacity. Replaced with a new pump, and regained the advertised lifting capacity. Before that, thinking my valve was bad, I took it to a hyd shop for testing, and it passed. I had already redid the seals and o-rings in the cylinders.

 

[garcol]

To marimus.. All fluids are topped off/up.
To Farmerford.. No i do not have to hold the bucket curled up.

I did however buy a 3 handle (spool/valve assy) to add a 3rd hydraulic cylinder to a grapple on the bucket. Not exactly sure what to call it (valve/spool?). But it used to do the same thing even when it had a two valve assy. Just not as bad.
Have to get me some T's and some gages and watch what is happening with pressures I guess....
Thanks guys. will let you know when i get it narrowed down.
Got too much to do and not enough time to do it all.. I know you all know what Iam talking about....lol
Gary