Front power lift on a Kubota B4200D

[EggerDE]

Hi folks,

I want to add a front power lift to my Kubota B4200D to be able to lift some counter weight or a transport box etc.

I figured out I have a plugged knob below the seat, where I can take oil from.

However, it is not completely clear to me and my friend (hydraulic professional), how it works. We looked into the manual, the parts list and into documentation for buying replacements from coleman equipment.

My current understanding is the following:
1. It is possible to connect something to this hydraulic takeoff
2. Then the knob has to be turned with a certain position of the lever for the 3point hitch.
3. Now, I think, there is a continuous oil flow out of this takeoff to the implement valves and back to the tank.
4. The 3 point hitch cannot be used while using power from this takeoff

Is this correct?

If yes, I cannot directly connect a power cylinder lift here, without any valve or lever.
Initially I thought I can connect something here and control it with the 3 point hitch, but this seems not possible here.

The most convenient solution would be to have some valves, where the fluid can go to the 3 point hitch, if the valves are in center position.
However, for something like this I would have to cut in the pressure line? Is this a dumb idea?

One last question, which we were wondering about today for some time:
Where is the pressure relief valve in the system? Is it in the pump? I could not find anything in the documentation about this. Or is there no valve at all?

Best regards from Germany
Egger

 

[North Idaho Wolfman]

Hi folks,

I want to add a front power lift to my Kubota B4200D to be able to lift some counter weight or a transport box etc.

I figured out I have a plugged knob below the seat, where I can take oil from.

However, it is not completely clear to me and my friend (hydraulic professional), how it works. We looked into the manual, the parts list and into documentation for buying replacements from coleman equipment.

My current understanding is the following:
1. It is possible to connect something to this hydraulic takeoff
2. Then the knob has to be turned with a certain position of the lever for the 3point hitch.
3. Now, I think, there is a continuous oil flow out of this takeoff to the implement valves and back to the tank.
4. The 3 point hitch cannot be used while using power from this takeoff

Is this correct?

If yes, I cannot directly connect a power cylinder lift here, without any valve or lever.
Initially I thought I can connect something here and control it with the 3 point hitch, but this seems not possible here.

The most convenient solution would be to have some valves, where the fluid can go to the 3 point hitch, if the valves are in center position.
However, for something like this I would have to cut in the pressure line? Is this a dumb idea?

One last question, which we were wondering about today for some time:
Where is the pressure relief valve in the system? Is it in the pump? I could not find anything in the documentation about this. Or is there no valve at all?

Best regards from Germany
Egger

That port will only get flow when you move the three point control.
All your doing when you change the valve on the cover is redirect the flow to the port instead of the three point cylinder.

It will run a single action cylinder not a dual action cylinder.

Thew pressure relief for the hydraulics is in the three point control.

 

[North Idaho Wolfman]

If you want full control for a spool valve and a dual action cylinder you will need to cut and loop in a spool valve.
Make 100% sure the spool valve has a pressure relief valve built into it or you will blow the seals out of the pump.

 

[Russell King]

You and your friend could just remove the pipe #60 in the picture above and attach a hose (or hydraulic line) with a banjo bolt to the hydraulic pump outlet (bottom of the pump) [this would be pressure supply line to the valve]. Then at the other end of #60 pipe install another hose with a banjo bolt [this would be pressure supply line to the three point hitch]. If those two hoses were connected together they would simply be replacing pipe #60. But if you put an OPEN CENTER valve that has a POWER BEYOND sleeve between the two hoses, then you can control a hydraulic cylinder. The new valve will also need to have a tank return line going to the tractor sump. (there are other names for the power beyond function like “high pressure carry over“ that may translate to German better)

Here is the three point control valve showing the pressure relief valve

 

[EggerDE]

Wolfman, Russel King, thank you very much for your reply.

I think I try to start with a single action cylinder for lifting with a front power lift. As I understand, for this, I only need to connect the lifting cylinder with the three point outlet. I think its very convenient using the hydraulics this way, because I can use the already available three point control and the existing pressure relief valve.

@Russell King I guess the pressure relief valve is #020?

One question concerning this knob:

On my machine this knob is very hard to turn. I can only move it by some degrees and quite some force applied. I guess it was never turned in the last 30 years, as the plug also sat very strong Any ideas how to make the knob turn without breaking it?

My hydraulic specialist supplied me with some parts and a hose, so, if I can turn the knob, I can see if the hydraulic flow works like expected.

 

[North Idaho Wolfman]

This is the pressure relief section, your pointing to the spool valve.

I would be pulling the cylinder cover 4 bolts and remove the guts and clean and polish all parts and the bore, replace the O-rings

 

[Russell King]

Since you can move the knob a little, you can try to spray the shaft with a penetrating spray like PB Blaster, Kroil, etc. Since you are in Germany, I don’t know what products are available there.

Spray the shaft where it enters the tractor case. Try to gently rotate the shaft slightly in both directions. Then move it back and forth several times if it does move. Then spray again and walk away for a few hours or overnight. Spray, move back and forth. Repeat over and over until you get it loose or you give up.

Just be careful to not shear the shaft or you will have more trouble than you do now. It should move both directions (CW and CCW) unless it is at one of the limits.

 

[EggerDE]

Hi there, just wanted to give a small update. Unfortunatelly I only can visit my small machine on the weekend.

I managed to unmount the knob, as I wanted to clean it out. However, after I had it removed from the tractor it turned around easily and smoothly. After turning it some times I built it back, however I cleaned out some dirt on the cylinder head, as the oil there looked very dirty.

Unfortunatelly I find it very difficult for me to get the original spare parts, thus I just put everything back together with the original seals. I also made some tests and could not encounter some leaks under load, so hopefully the old seals can stay a little longer Anyone has any thoughts about that? Is this a no go or can do, if must?

I will now proceed with the front power lift. I will start to connect it with a hose, as bending a metal pipe seems rather difficult (can make it in my work place, however it seems rather difficult without the tractor being onsite).

Concerning the front power lift I am not yet decided which one I should add.

Thank you guys for your help.