Loader with some hiccups, curls slow or not at all, lower; raises then lowers....

[project_X]

I have a Koyker loader on my Yanmar. It has a dinoil joystick to control the loader. Today when I was moving some earth, the loader would not curl and then curled slow. While lowering the loader, the loder decided to go up before going down.
Fluids are clean, 3pt lift works fine.
I suspect that the load check valve(s) needs to be cleaned out, but don't know where to start?

Any advise would be helpful?

Thanks,
Rob

 

[J_J]

I believe I would install a hyd gage in the system, and check the pressures. The spool load check normally only work to prevent the load from slipping when you are shifting the valve.

 

[project_X]

I believe I would install a hyd gage in the system, and check the pressures. The spool load check normally only work to prevent the load from slipping when you are shifting the valve.

JJ,
What do you think might be the problem? I will measure the pressure, but what do you expect me to find when I do the test?

Thanks,
Rob

 

[J_J]

If the 3pt works the pump appears good.

If the gage is installed at the input of the FEL valve, then anytime you activate the curl or lift levers, and there are good cyl, the cyl will extend or retract and when they get to the end of the travel, the PRV should relieve and indicate relief pressure. Just one of the cyl in a pair might be bad , and give weird results.

You can also exchange the lift hose with the curl hose, and verify some things.

If you could get your hands on a flow meter and pressure gage, you can so some further testing, such as what components have flow and pressure. and how much.


To test curl cyl, disconnect the rods at the bucket end. Remove hoses from cyl and cap hoses. Now, activate the cyl you are testing and see if it will extend and retract and relieve at the end of the stroke. Do the same for the other cylinders.

If you have a load and the load checks are held open by debris, when you try and shift, the load might drop until the pressure over rides the load imposed pressure.

 

[Leejohn]

Sounds like you might have a coupler that has come unhooked.

 

[jinman]

Sounds like you might have a coupler that has come unhooked.

+1 - I agree. The quick disconnects are the first thing I would check. For any weirdness in movement, the QDs are suspect. It only takes a few minutes to disconnect and reseat the connectors.

 

[project_X]

+1 - I agree. The quick disconnects are the first thing I would check. For any weirdness in movement, the QDs are suspect. It only takes a few minutes to disconnect and reseat the connectors.

I only have two quick connects on my hydraulics one from the pump to joystick and a return to the tank. If those get disconnected....I've got big problems, I think I shear a piece in the pump.

I will probably switch the hoses from lift to curl to see if it is the valve or cylinders.

 

[J_J]

Quick disconnect fittings to the FEL valve from the pump is not a good idea. If either one of those QD.s should ever get released, the pump pressure would go to max, and probably burst the hose, valve or pump. Even if it were released with the tractor off, when you started the tractor, you would hear a bang, and something is busted. I would hard fix the hose to the valve.

 

[project_X]

Quick disconnect fittings to the FEL valve from the pump is not a good idea. If either one of those QD.s should ever get released, the pump pressure would go to max, and probably burst the hose, valve or pump. Even if it were released with the tractor off, when you started the tractor, you would hear a bang, and something is busted. I would hard fix the hose to the valve.

That is how my loader disconnects from the hydraulic system so I can remove the loader from the tractor.

How is that usually done?

 

[jinman]

That is how my loader disconnects from the hydraulic system so I can remove the loader from the tractor.

How is that usually done?

I think your loader and joystick must be removed together. Is that right? Is the joystick mounted on the loader instead of the tractor?

If the answer is yes, you probably have a relief valve in the system before the quick connects so that it will open if one pops loose. Your tractor just treats your loader as another open-center load.

On many/most of our tractors, the joystick is on the tractor and plumbed with rigid piping. The joystick connects to the loader via two sets of quick connects (4 total).