hydrolic's system education

I'm wondering about the efficiency of the equipment I own. The loder bucket today struggled to manage a lift would have thought it should have covered. My questions pertains to improving my equipments lifting ability.

If your pump pressure is consistent and your lines are all common in size. Can you improve the lifting ability of your loader with a change in cylinder size/bore? Seems to me the fluid pressure is what defines the capibity of the work that can be completed. Pivot angle also contributes but pressure and flow are the A and B factors in the system.

WR[/b]

Yes, you can increase your lifting capacity, but at the cost of speed. The pump output is constant, meaning the bigger the cylinder, the longer it takes to fill it. There is also a design capacity engineered into the frame of the loader and the cylinders are engineered to work within that design capacity. Replacing with bigger cylinders will most likely result in breaking the loader.

Did the loader used to work better? Or is it new to you and you suspect it's not properly matched to the pump?

There should be recommendations from the loader mfg for the pressure and pump volume. You'll need to research this and compare the numbers. Test the pressure actually being delivered to the lift cylinders either under heavy load or fully extended.

Also, does the lift stay up when the valve is in neutral? If it leaks down, there may be a cylinder piston seal leaking internally.

Like Hayrack said, trying to increase the lifting ability beyond the intended use will probably break something!

Hayrack is right. You can get more power out of your machine, at the same flow and pressure, but the movement will be slower due to the larger area in the cylinder having to be filled. Too, given that most machines are designed around a certain set of parameters, changing cylinders, or doing anything to significantly change the lifting capabilities opens the door for damage to the machine's frame, be it cracks, or worst case a catastrophic failure.

To see the differences in the forces applied by various sized cylinders, and some common pressure points, take a look on the chart at the provided link. As you'll see, even a 1/4 inch change in diameter on the cylinder (1-1/4" to 1-1/2") will make a change of nearly 1100 lbs at 2000 psi. Basically the higher the operating pressure, the more change imparted due to the diameter change to the cylinder bore.

That said, before I did anything else, I'd check the pressures on your hydraulic system. Usually what happens is that as the pumps age, the start to wear out. The result is the pumps bypass pressure internally and tend to put out less than normal pressure and flow. Usually most folks don't notice the change in either pressure or flow as the reduction comes on a little at a time, over a long period. Too, many machine operations don't require the use of full pressure, so, once again, no change is noticed until a use comes about that requires force/pressure that is no longer there.

Hope this helps.
Cylinder force chart

No change that I know of, just the first heavy lift Ibe done. The
loader Cylinders would not lift my new plow off the trailer that I
had chained to the arms but the bucket tilt would lift it.
Different cylinder and rotation of the bucket not a linear lift like
of the loader cylinders. I need to check filter, I also know my
tractor is not known for its hydraulic system being robust. I just
want to make the best if the system I have.

You need to use a proper pressure gauge and find out what pressure the system has in each circuit.

If a circuit is low, then find out if you have a a screw adjustable pressure regulator valve. Some valves may require a new spring or to add washers to increase pressure. Srings can break or get weak with age.

It might help if you can determine in advance from the manufacturer what the system pressure is supposed to be. Each circuit should probably be about equal ib pressure to the other circuits.

You need to find out at what the peak pressure is
when trying to lift and the loader stops. It it's
reaching factory specs -then adding larger
cylinders or raising the pressure will likely
exceed the engineering limits of the loader frame.
If not- raise the pressure. Could be a problem
with the main relief valve and might also have a
circuit relief valve just for the loader.

What happened isn't unusual, so I think you just reached the limit of what your machine is rated for. Like you said, there is a difference in the way the bucket pivots as opposed to the way the loader arms lift the whole assembly. That being the case, the roll of the bucket, or what mfgs usually rate as breakout force, will be greater than the lifting force obtained by the loader arms. So, if you were able to lift with plow by rolling the bucket but not by lifting the arms, I don't think you have any real issues with the hydraulics. Too, if the lift cylinders held position, and didn't collapse, that also tells me that the packing in them should be OK, and that the port relief (if it has one) on that portion of the system is OK too, otherwise it would have popped off and set the load down the second you got it raised a little, if not sooner.

That said, I've got an old 3500 Ford with a loader on front, and the backhoe attachment on the back. It has forks on it right now and appears like it should pick up a pretty good load, but the rating on the loader is only around 500 lbs. In other words I have discovered the hard way that it won't do as much as I thought it would do. In fact I've got many things sitting around that were moved with a skid steer and a set of forks, and the Ford won't touch them.

I did not experience and drift with the pic, just thought the loader should have been able to pick it off the trailer. I've not had any other issues and have been thinking about a fluid change and filter flush. Might be the right time to give that a shot and see what happens.

WR