Single acting cylinder help

[tommu56]

you said it had some sort of vent fitting right?

How hard would it be to add the second hose?

plumb in the second line to were the vent fitting is and see what it does.

with out pictures and or schematics suggesting whats wrong is an educated guess on out part
I'm sure it as some thing to do with the regenerative or the flow in the valve. Was it connected to the rear remotes on the other tractor what brand ect?

tom

 

[CraigM]

Tom:

I'd bet the tractor that a second line in place of the vent would fix the problem, but it's just not worth the trouble. The other tractor was an old Farmall H.

I'm sure you are right about the cause being some wierdness in the valve, I just wish I knew what.

Pictures are just not in the cards right now. It will take at least a week for the ground to dry out enough to get the tractor out. It's so wet in front of the shed where we have it parked that I wouldn't be able to get back up the little slope in front even in 4WD. I can lower the wagon when I need to, even if it's inconvenient so it's not a real big deal. We would probably be hauling any load with the JD 3020 anyhow, and I know that works with single acting cylinders.

Thanks to all for the ideas

 

[Leejohn]

Where is the loader valve out port going to? It should be going to tank and no where else.

 

[CraigM]

I assume it goes to the tank. I haven't modified it in any way.

 

[Leejohn]

I'm just shooting in the dark, but check it out. The loader valve might not be plumbed right. If it is and everything else seems to be right, then maybe, then I would look at the valve. How many hoses are hooked to the Valve?

 

[ol'George]

Maybe I missed something here, but the load check valves most loader valves have, seem to be comming into play, they make sure you have pressure to lower/raise the load in a controlled motion so it don't drop/raise the load unsafely. with no pressure from the pump,( engine stopped) they uncheck and the "float" position drops the wagon (& loader)
you need to hook the wagon cyl. to the remote cyl. outlet and select "single action cyl"

 

[J_J]

In an open center valve, in neutral, and when the engine is off, the work ports are blocked, but they can leak down over time. Load checks inside the valve only work to prevent the FEL arms/bucket from moving when you are shifting the valve. There are external load checks that can be pilot operated. The float position opens the work cyl so the cylinder can move freely. If a single action cyl does not have sufficient force on the shaft in the vertical plane, it must be helped in some way. Maybe modify the geometry, add springs, etc.

 

[ol'George]

You speak what I have experanced to be true, no question
I understood him to say it would only go down in float with the engine off (not withstanding normal leakage)
I feel that would be caused by the load check on it's seat by the absence of pressure in the valve from the other side of the cylinder,to uncheck the ball.

We both understand the dead heading of the pressure relief because no circuit to the other side of the cyl with the pump running ( valve in down position). if it were not for the load checks it would of dropped
( understanding with sufficient load on the cyl to compress it)
now, please point out what I'm am missing?

 

[J_J]

If those QD's are not seated fully, there will be blockage, and maybe enough to slow the flow of hyd fluid to build up some pressure, and if the cylinder has pressure in the float mode, it will not or maybe not come down. You can do a quick test, turn engine off, take the out/return hose going back to tank, and place in a bucket. Cylinder should stay extended, because the spools are blocking the work ports from the main flow galleries. When you go to float, you open the spools to let fluid flow freely. If the out or return hose is in a bucket, then the fluid from the cyl should bleed out into the bucket when float is activated. It should lock the cyl if valve is in neutral.

 

[CraigM]

J_J and George. Sorry, I was away for a few days. Sounds like you guys have explained my problem. It seemed like there must be something going on in the valve that I didn't know about. I had never heard of load checks. I guess I could run those tests and confirm things, but load checks explain my symptoms and that's good enough for me.

I don't have any remotes, that's why I used the loader valve. Sounds like remote valves come with load checks that can be turned on and off by selecting single acting cyl?

It's not worth the trouble, so this question is academic...what if I used the power beyond port on the loader valve to run the wagon cylinder? Would a valve that I'd connect to PB come with load checks? Are they a default standard in open center systems...would it be a good assumption that any OC valve I found would have them?