3 point control lever raising bucket

[ggtechman7]

I have 23 HP Rhino, and the 3 point contol valve did not work, it had a broken shaft, so I ordered a new one from Homier at parts.farmprotractors.com. I installed it and with lever in rear position I hear the hydraulic pump cavitating, and in the forward position it lifts the bucket.
I am not sure what to check now? The hydraulic power lift is like the farmpro, and I have a drawing of it, but I do not understand how it functions?

 

[Affordable]

It sounds to me like it's not plumbed correctly,The pressure side of the pump should go to the inlet of the frontend loader valve and out of that valve to the feed of the 3-point valve ?

Tommy
Affordable Tractor Sales Co
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[ggtechman7]

I did not do anything with the pressure or the return hydraulic lines, and before the 3 point worked OK with the old valve until it broke. Could it be the 3 point piston is jammed in a position where the 3 point doesnt work, and is sending high pressure to the bucket loader? But then how could the bucket control valve be bypassed in the circuit that it allows the bucket to raise? When I operate the bucket control valve it operates normaly: raise, lower, tilt. I may just have to open up the piston end and see if its not jammed.

 

[greg_g]

If Tommy's suggestions don't apply, I suspect your loader may be plumbed into the wrong place on the lift box. Technically not wrong wrong, just inconvenient wrong. Is one of the loader hoses connected to a 90 degree fitting on the side of the lift box? If so, there may be a hex head just to the side of it. It looks like a bolt, but it actually controls a diverter valve that shunts hydraulic fluid between the lift cylinder and that 90 degree fitting.

Try turning the hex head in the opposite direction to see if your loader works again. If it does, it unfortunately means now your TPH won't work. Since 90 degree fitting is intended for 1-way cylinders, it's an either/or proposition. If you find that this to be the case - with the hex head all the way to one direction, the loader works. With the hex head all the way to the other direction, the TPH works. Never the twain shall meet, unless/until the loader gets plumbed somewhere other than into that 90 degree fitting.

//greg//

 

[ggtechman7]

I will check and see if there is a hex head/diverter valve on the Power lift. I attached a picture of the power lift. I did turn/tried to adjust #3, it stated somewhere that it was the lowering speed adjustment for the 3 point, but nothing happened, it just leaked hyd fluid. I will also check the hydraulic lines coming from the pump to see how they are connected, and I will report back.

The hydraulic power lift is a mystery to me, as to how it works, how does the hydraulic pressure control the piston movement... did anyone out there dissasemble one of these units?

 

[erj]

Read through the various notes, is this what is happening?

1. Installed new 3 point control valve (where is that valve located?)
2. Hydraulic lines were installed on new valve the same way as on old valve.
3. With the old valve, 3 point operated as it should and Front End Loader operated as it should.
Now:
1. Moving 3 point control lever to rear causes cavitating sound in hydraulic pump.
2. Moving 3 point control lever to front causes FEL bucket to lift.
3. Bucket (FEL) control valve still operates loader correctly.
RonJ

 

[ggtechman7]

Hi Ron, this is what is happening, I did not get chance to work on it more:
1. Replaced new 3 point control valve (located on right side of hydraulic lift, attaches with the three bolds #57 in the picture)
2. Hydraulic pressure line only connects to the valve on the bottom.
3. Moving 3 point control lever to rear causes deadheading sound in hydraulic pump.
4. Moving 3 point control lever to front causes FEL bucket to lift.
5. Bucket (FEL) control valve still operates loader correctly.

 

[ggtechman7]

I followed the hydraulic lines and from the rear of the hydraulic pump, line goes to the IN of the Loader Valve (Cross Valve Made in USA). From the OUT of loader valve line goes to the bottom of the 3Pt Control valve. From Top Front area of the Hydraulic Power LIft a larger line goes back to the side of the hydraulic Pump.
In the picture of the power lift I noticed that item #3 has a knob on it #1, mine does not have a know, but wahat is that adjustment for? and how do you know where to adjust it to?

 

[greg_g]

I can't quite picture your loader circuit in my head, as it sounds like the loader was plumbed in series with the TPH. I'd have expected a parallel circuit. Any chance you can post photos?

The thing without a knob is your flow control valve. It's typically used in conjunction with the three point hitch, to regulate how fast the hydraulic fluid returns to the sump. When you have no load on the lift arms, you want it wide open so the arms go down under their own weight. When an implement is mounted, you then regulate the speed at which the arms drop (it doesn't affect lift speed). In most cases - the heavier the implement, the slower you want the return flow adjusted.

If you've never used it, it may be stuck. But the valve body itself can be removed for cleaning, just be careful to first remove the set screw that's recessed into the face of the valve housing. And those - are often painted over.

//greg//

 

[ggtechman7]

OK, problem solved!!! It was the valve #3 (without knob) that was screwed all the way down, because that is when it did not leak hydraulic fluid around it, but it stopped all action to the 3 point. I turnded it all the way counterclockwise but it did not come out, so I could inspect it. So I screwed it back in about half way down, and 3 point works good, up and down by using the lever. It still leaked hydraulic fluid so I wrapped the threads with teflon tape to stop the leak. Thanks for all the suggestions, now I can get to work boxscraping and brushhoging.
I still have one more issue with the FELoader where its springgy about 6" before it feels solid, I may start another thread on that later.

 

[erj]

I am glad that you got it working properly again!

However, if the rest of you do not mind I would like to further my continuing education of the hydraulic system.
Can someone explain what happens in the system when:
1. The three point flow control valve is completely closed.
2. The three point control lever is pushed forward into the Lower position.
3. The FEL bucket raises.

It would seem to indicate that the hydraulic fluid reverses normal direction and somehow activates the Raise portion of the FEL valve.

Is that possible?

Thank you,
RonJ

 

[greg_g]

I believe you're in the same camp with me and Tommy. Doesn't seem that loader circuit was plumbed in correctly in the first place.

//greg//

 

[erj]

Techman,

Even though you got your problem solved, perhaps you can help us with understanding what was happening.

Look at the pictures below to see if they are like your plumbing.
There is a line A from the pump to the FEL control valve whose controls look something like these.
There is a line B from the FEL control valve to the 3-point valve.
There is one more line that you mentioned that goes from the tank to the pump.

Is this correct? Are there any other hydraulic lines?
RonJ

 

[ggtechman7]

RonJ- Continuing the discussion in depth is great, the more we know about our tractors, the better we could take care of them and keep them running better/longer. Regarding one of your question I found out following about the 3PtControlValve:
"Floating control is suitable for field plowing. In floating control, the supporting wheel is needed for implement. During plowing, hold the control lever of distributor at "lowering" position (i.e. push the control lever of distributor forward with the return stopper. Do not return the control lever to the neutral position). The hydraulic circuit is then in "floating" control. Using floating control, the plowing depth is controlled by the change in height of the supporting wheel. The uniform plowing depth will be obtained in the field with changes of soil resistance.
In looking at your pictures, that is how my hydraulic lines run, looks like your pressure line runs in series through the FEL valve also. I have attached a sketch of how my system inter-connects. I'll see if I can take some actual pictures of system in next few days.
George

 

[ggtechman7]

I was able to take some photos of the hydraulic system, so here they are. Again that flow control valve adjusting screw was screwed in down all the way clockwise, which kept the 3 point from working, now it is at about mid way up between fully closed, and fully open.