FEL Hydraulics

[bill18163]

The FEL on my B2710 Kubota will not go in the down direction with any amount of force. All other directions have hydraulic force. The down direction is VERY slow. If you release the down valve by pushing the stick all the way forward it will go down very fast. But it doesn't work under hydraulic pressure. Anyone have any ideas????

 

[J_J]

You are going into float, and I think you have a QD not connected all the way.

If you have QD's in the work port, remove them and attach a hose in the work ports, and place the hose in a bucket and activate the levers for the FEL.

You could also attach a gage in a work port to check pressure. Put the loose hose in a bucket.

 

[bill18163]

JJ,
Not quite sure what you want me to do here. I did remove and re-connect all the quick disconnects. That did not cure the problem. Now do you want me to determine which circuit disconnect is for the down direction of the FEL and remove it and connect a hose to that port instead of the QD and route the hose to a bucket? If that is true then what am I looking for? What should I expect to see?

 

[J_J]

If you have flow out of the work ports, then the cyl should work if all the QD's's are good.

That is assuming that the pump is good and the relief is working right.

If you have flow and the cyl will build up pressure, then something will move or the relief will activate.

Do you know if the spool is moving in and out the same? Remove the bottom cap on the valve and make sure the nuts are all tight.

Even after resetting the QD's, they could still be bad. The only way to know for sure is to see if fluid is passing through the connected QD, and you do that by unscrewing the QD off the hose and see if you can pass fluid through the complete QD set with out the hose on it.

There is something that is not letting fluid into the cyl or not letting fluid out of the cyl.

If a lift cyl is raised and will not come down, something is blocking the flow, and therefore the QD's are the most likely to be the cause of the trouble.

 

[SSdoxie]

Here is a step by step of what JJ is trying to tell you;
Use your "float" position to lower it to the ground.
1.Disconnect 1 hose from rod end of the boom lift cylinder and put it in a bucket to catch the oil if it is working. Then start tractor and move the lever forward (pressure down). If oil comes out that circuit is working, so hook hose back up and go step 3
2. If no oil comes out the hose, trace that line back to the QD on loader valve and remove it. Put a hose in place of the QD, put other end of hose in bucket and try the above test again. If no oil comes out, you have a control valve problem. I oil comes out but did not on step 1, either your male or female QD is blocked.
3. Remove a pivot pin from end of 1 lift cylinder, start the tractor and move stick to raise, extending the cylinder a couple inches. (It will extend without raising the loader unless you hit end of stroke). Follow the line back from base end cylinder to find the QD. Take that QD out put the end in a bucket. Start tractor and try powering down again. If no oil comes out the QD (female or male) is blocked. The QD couplers can stick to stop flow in 1 direction.

 

[bill18163]

Well there are two caps on the bottom of the valve and I had just enough time today to remove one of them. Got a hand full of steel balls and a spring. There were four small balls and one larger one. Didn't see any thing that looked like a nut that might be loose. There was a lot of gunk in there and rust inside one of the sleeves. Cleaned it all up and put it back together and started up the tractor. Still have the problem. I will take the other cap off the bottom of the valve tomorrow and check it out. If that doesn't cure the problem I will move on to check out the quick disconnects. Just one question. Am I working in the right place? Where are these "nuts" that JJ mentioned that could be loose?

 

[J_J]

Some of the spools have nuts on the bottom of the spools to keep everything together. If they come loose, things do not work right. You might have to look at a diagram to make sure the parts are back together correctly. Some of those are for detent, float, spring center, etc.

If the parts are rusty or the spring is worn or broken, they will need replacing.

http://www.princehyd.com/Portals/0/products/valves/LVManual.pdf

This Prince valve PDF is for reference only.

The spool ends on this valve is held on by the two screws. Clean and lube real good, and if they hold water, some people drill a small hole in the bottom of the cap.

 

[wdchyd]

The FEL on my B2710 Kubota will not go in the down direction with any amount of force. All other directions have hydraulic force. The down direction is VERY slow. If you release the down valve by pushing the stick all the way forward it will go down very fast. But it doesn't work under hydraulic pressure. Anyone have any ideas????

Don't overlook the 3ph control valve in the "UP" position....some tractors will not go down if this lever is in the up position because the 3ph is trying to lift a load and is extended all the way up.....

 

[bill18163]

Well guys I feel like an idiot. WDCHYD was correct. I signed on here today to tell you how I went through all the suggested tests and could find nothing wrong and I saw WDCHYD's suggestion. I went to check the tractor and the 3 point hitch lever was engaged about three fourths of the way. I never noticed the hitch arms being up because I have my back hoe on the tractor right now. I don't know how the 3pt hitch engaging lever got pushed to the up position but it was. I even found a hydraulic shop here in town that would test and rebuild it and after this holiday week end I was going to remove the valve and take it to them. I did all that testing with the hoses for nothing and to top it all off I don't have my float position now. What I mean is that the joy stick will not lock into the float position. It pops out so that if you want to float the loader you have to hold it in float. I know what is wrong. When I took the cap off the bottom of the valve to clean it up as I mentioned before, all those little balls came out. I thought I got them all back in place but it's very hard to do with the valve on the tractor because it's all pointing in a down ward direction for the re-assembly. I'm going to have to remove the loader valve so I can stand it in the upward position on a bench and then remove the cap and re-assem the poppet balls so they stay in place. I think the four small ones probably stayed in place but the larger one that gets positioned at the end of the spring may have slipped off when I re-assem everything. One thing I did get from this though was a good education on how to test out the valve and you can bet I will never forget about the 3pt hitch valve being open!!!!!!

 

[J_J]

I pasted this the other day, and it is related to your problem.

The 3pt can pressurize the hyd circuit back to the FEL valve. Don't know why the pressure blocks the fluid only in the down position. I always thought the cyl expended fluid flowed out the OUT port. but it appears the pressurized line will block the cyl from dumping the fluid.

http://www.tractorbynet.com/forums/yanmar/216990-adding-grapple-3.html#post2497320

Post #29