kubota L235dt Hydraulic issue

[captjack]

I have an L235 dt with a loader. It has an open system. When I bought the tractor it had a 2 lever control for the loader. Since it was leaking a little I decided to upgrade to a single lever design. I purchased a Brand mono block valve with regen.

I have been having some issues. The hydraulics seem to get weak when heated up, both the 3 pt and the loader.

I can get more power to the 3 point if I press down on the loader valve at the same time. When this is done the 3 point can pick up more weight.


Just the other day I noticed that I no longer have the "float detent" on the loader valve. I still had the previous problems prior to this happening but thought I would mention it.

I called Brand and after a long chat the guy says I need more restriction ? I think he wanted me off the phone.

Any thoughts about this ?

 

[AKKAMAAN]

I have an L235 dt with a loader. It has an open system. When I bought the tractor it had a 2 lever control for the loader. Since it was leaking a little I decided to upgrade to a single lever design. I purchased a Brand mono block valve with regen.

I have been having some issues. The hydraulics seem to get weak when heated up, both the 3 pt and the loader.

I can get more power to the 3 point if I press down on the loader valve at the same time. When this is done the 3 point can pick up more weight.


Just the other day I noticed that I no longer have the "float detent" on the loader valve. I still had the previous problems prior to this happening but thought I would mention it.

I called Brand and after a long chat the guy says I need more restriction ? I think he wanted me off the phone.

Any thoughts about this ?

we need to get more details from you.....start with this...
can you refere a web link to the new valve you just plumbded in?
Is your system "heating up" or "warming up"? Can you locate where system creates heat?

 

[captjack]

I installed the valve into the lines that fed the old valve. Pretty straight forward.

When I say heat - I am referring to "after the tractor has been run for a while" I have not actually measured it.

I have checked fluid(replaced several times with new filter)

Fluid is the standard UDT as per the manual

The valve is http://www.brand-hyd.com/lv/lv-info.htm

LV22RFSTKAB
............... Two spool valve, tandem center fourth position regen spool (R), fourth position spring center (FS), tandem center (T), fourth position float (K), joystick assembly (A), adjustable relief (B) 2000 psi (138 bar) setting

 

[kennyd]

Is there 2 or three lines (not counting the four to the cylinders) hooked to the new valve? Did you get the "power beyond" option on the new valve?

 

[captjack]

There are 2 lines - 1 feed , 1 return. I have the option of the power beyond but it is not being used. I would need to purchase a kit and install it for it to work.

 

[kennyd]

There are 2 lines - 1 feed , 1 return. I have the option of the power beyond but it is not being used. I would need to purchase a kit and install it for it to work.

Well, at this point you need to define "heat" and isolate where the heat build up is like AK wrote. If you plumbed in a open center valve then all should be OK-possibly there is something wrong with that valve.

 

[AKKAMAAN]

I have an L235 dt with a loader. It has an open system. When I bought the tractor it had a 2 lever control for the loader. Since it was leaking a little I decided to upgrade to a single lever design. I purchased a Brand mono block valve with regen.

I have been having some issues. The hydraulics seem to get weak when heated up, both the 3 pt and the loader.

I can get more power to the 3 point if I press down on the loader valve at the same time. When this is done the 3 point can pick up more weight.


Just the other day I noticed that I no longer have the "float detent" on the loader valve. I still had the previous problems prior to this happening but thought I would mention it.

I called Brand and after a long chat the guy says I need more restriction ? I think he wanted me off the phone.

Any thoughts about this ?

According to tractor data, your original valve is rated 6.2 gpm....your new current valve is rated for a 10gpm flow...that means your current valve might be little oversized....and would require more throttle (restriction) on the control valve, to build enough pressure to move loader....that means that most of your flow is bypassing (diverted) in the control valve unless you move spool (lever) to the end. This is probably what your shop tech is referring to.....

You HAVE to pull/push valve lever to max end to divert entire flow to cylinder...that will also reduce overheating of oil....put entire flow to real work, not into heat....increase pump flow with engine throttle if needed (gaspedal)

This have just recently been discussed in one of my threads...under sized and/or over sized control valve

 

[captjack]

So how do I fix what I have ? Find a valve the is rated closer to 6.2 ?

 

[kennyd]

I personally do not believe the difference between 6.2 GPM and 10 GPM makes a hill of beans of difference in this case. PLENTY of peaple plumb in 25 GPM valves on small tractors and equipment because they are cheap (the valves that is), smaller valves usually cost more.

Get a IR thermometer and do some testing...I still think that valve may be bad/wrong-possibly it was mis-packaged or labeled, where did you get it from?

 

[captjack]

I called Brand Hydaulics again and spoke to a tech in great length. The out come was this.

The tractor has an aux flange for hooking up aux hydraulics such as a loader. The manual says to use a valve of the "power beyond type" when operating the flange block.

I dont have it set up that way. I have the inlet and the outlet ports on the flange block plumbed to the psi side and the return side of the loader valve. This was the way i got the tractor. It looks to be the way the tractor was set up originally.

The tech said that I needed to install the power beyond plug in the loader valve and plumb that to the flange, then get another hydraulic line made up and run it from the return side of valve to the return port under the seat of the tractor.

The odd part of this is that the original loader valve was not plumbed this way. The original valve was the old 2 lever control that is usually seen on an old tractor like this one. It had the in and out from the flange and the 4 hoses going to the loader from the valve.

The tech seemed to think that I would have a lot more power to the loader and three point with the new plumbing




Thoughts ?