FEL Hydraulic Issue

[tdkins]

This is my first post but I've been researching on here for a while. I'm trying out a Kubota M5030SU with M1000 FEL. The lift on the FEL is leaking down kind of fast, even when its running. I raised it and measured last night and then disconnected the lines on the lift and it didn't drop any. The tilt on the bucket doesn't seem to be losing any pressure either. I lowered the bucket down and tilted it up putting pressure on the bucket, left it for several hours and hadn't moved any. I believe I've narrowed it down to the valve on the lift side. I don't really know where to go from here, or what to expect on a repair cost?

Another question, is there any reason that I couldn't switch the lines from the lift and tilt? I don't have any experience with hydraulic repair.

Thanks

 

[tdkins]

I also forgot to mention I had a bale of hay on the 3Pt for 2 days and it didn't drop any.

 

[J_J]

You might try removing the relief valve and inspect/clean.

Do you know if the levers are going back to center. They are supposed to be spring centered, but springs get weak or break.

Look under the caps on the bottom of the valve for corrosion, rust, etc.

Spools do wear, and most are not replaceable.

Install a gage and provide us with some test pressures.

 

[SSdoxie]

Just because you disconnected the lift lines form the valve and had no leak down does not mean a cylinder is not by-passing. If a cylinder packing is bad, it will leak equal pressure to both sides of the rod and base end having more surface will try to push up so loader won't drift if oil can't get away. There a couple of ways to test the cylinder:
Swap hoses from lift to tilt spool and try it. If it still leaks it is likely a cylinder packing.
Or raise lift part way (only a small ways off the ground), shut everything off, & disconnet QD from the valve then loosen a hose at the rod end of the lift. If it drifts and oil comes out the fitting 1 or both of the cylinders are leaking. Be very careful doing this. Put a rag over the fittings as you loosen it, if a bad leak it could drop quickly.

 

[tdkins]

I checked and the handles are going back to center. Tomorrow I'll try to take the caps off and see what they look like.

I'll try lowering the bucket tomorrow also and loosen the line at the rod end of the cylinder. If I understand right with the QD disconnected I should not lose any fluid when I loosen it. I may switch the lines tomorrow evening as well and leave it over night and see what happens. Should the pressure be the same coming out of all remotes?

Thanks.

 

[J_J]

What so you mean about the pressure on the remotes?

Pressure is developed by the cyl or hyd motor doing work. You will have different pressures with different loads.

If you are trying to see what the pressure on the relief valve is, then you would plug in the gage and max out a cyl and the FEL relief should come on and the pressure would be indicated on the gage. You will see varying pressures as you use the loader, caused by say a light load or heavy load or empty bucket.

What you want to see, is, if the pump and the cyl are getting the most they can out of the hyd system. Diminished pressure can be caused by worn parts, leaks, debris clogging some parts, pump worn. Light load.

If you check the hyd system and read the specified pressure on the gage, then you can assume the hyd system is working as advertised.

No pressure and no flow = not good. Your trouble shooting techniques will come into play here and help you isolate the faulty unit or parts.

One should know how something operates in order to do some logical trouble shooting.

 

[tdkins]

By "pressure at the remotes", I meant that all four QD locations should have the same pressure. That the lift does not require more pressure to operate than the tilt on the loader and there would be more fluid passing through on one remote(line) than another. My previous thread probably did not have the proper terminology in it.

Like I said before I am very green when it comes to hydraulics, but I'm starting to get an idea of how they work. I'll work on getting a gauge tomorrow as well to test.

Thanks

 

[J_J]

It is hard to prejudge pressure unless you have lifted the same item before.

Yes, the flow and pressure will vary on two different ports, because of lever movement, and the load each cyl has.

You can work two controls at the same time, and the flow will divide.


PARALLEL VALVE is a multiple spool valve whereby all spools may simultaneously control different functions. The oil flow will be divided equally providing the operating pressure requirements for all functions are the same.

The function requiring the lowest pressure will operate first. The next function will operate when pressure reaches it’s requirements, before or after the first function is fully operated.

If you installed a hyd gage in each hyd circuit you could see the pressure required to do the work.

 

[tdkins]

I found a line leaking on the tilt, Switched the lines between the tilt and lift at the quick disconnect and it is leaking down just the same as before.