Allmand TLB

[Dwellonroof]

Alfaggoma is that the Italian co who makes the gear pump

No that is the rear hydraulic drive motor hose the gear pump is Eaton

 

[Dwellonroof]

In which case if you steered left you would go right…. But anyway I guess mine is set up a little different then because I don’t have 2 steering lines coming off that gear pump in the photo, I have ONE line that leads to the steering orbitrol (which than has 3 lines from there, two of which are for steering cylinder; same size like you kindly pointed out, and then a to tank line). BUT the SECOND line coming off the gear/charge pump goes to the loader valve. Seeing as the gear/charge pump has a 1500 psi relief for steering circuit (which has priority) with the remaining flow being provided to the loader control valve i thought their was a chance those two lines were cross crossed. The two lines are actually one right above the other and I so desperately wished the lines on my pump came off the same side as yours (confirming your comment on orientation) but in fact they are opposite side leading them right into my forward reverse arm

I really don't know why the 2 steering lines because my orbitrol has a return to tank and looks like return to suction if it didn't have the second line on the suction side I could install a relief valve in that port I am thinking.

 

[River Valley Landscaping]

I really don't know why the 2 steering lines because my orbitrol has a return to tank and looks like return to suction if it didn't have the second line on the suction side I could install a relief valve in that port I am thinking.

It has two steering lines because it has a double rod end cylinder, so in the steering circuit it’s not flow In for one line, and flow out for the other. Instead both lines travel too and from depending on which way you steer

 

[River Valley Landscaping]

 

[Dwellonroof]

It has two steering lines because it has a double rod end cylinder, so in the steering circuit it’s not flow In for one line, and flow out for the other. Instead both lines travel too and from depending on which way you steer

I'm referring about the 2 lines on the pump itself.

 

[River Valley Landscaping]

I had a look at the parts manual for your model this morning and it is kinda confusing with all the different models. In your picture you posted of your gear pump, above the A in Alfagomma there are two lines that come off that side of the gear pump. One on top of the other vertically. They look to be close in size. On my allmand they are the same size both 3/8”. One line powers the steering valve circuit and the other line powers the loader valve circuit. My original comment on this thread was asking if you had double checked those two lines have not been swapped with each other, routed from the wrong port in the gear pump. The manual doesn’t do a good job showing which hose connects to the top port and which hose connects to the bottom port. So if someone has messed around in there before it could easily be overlooked. As far as I know only one of the ports out of the two has the lower relief pressure and that is for the steering circuit…. When I bought my allmand the previous owner had the tank line and supply line of the steering orbitrol connected to each other’s ports without knowing it. He said he replaced the orbitrol motor with a new one but yet still didn’t have power steering and he couldn’t figure out why. He thought it was something to do with the pump and gave up and put it up for sale for penny’s on the dollar of what it was worth. I used the tractor for almost a year without ever looking into it because he seemed knowledgeable and I didn’t second guess his judgement. Over the first year I owned it the steering cylinder started to leak more than just a random drip here or there and since it came with a box full of extra seal kits I figured hey why not? So I replaced the seals in the steering cylinder. Upon reinstalling the cylinder I followed the hydraulic lines back up to steering orbitrol just to check for any splits in the hoses. This is when I realized the IN hose was connected to the OUT port, and the OUT/TANK hose connected to the IN port of the orbitrol. I sat in the middle of winter in my ice cold cramped dimly light shed/garage laughing for a good half hour at myself upon this discovery. Then I thought about it for a few minutes and realized the previous owner must have just removed all the hoses from his “non working” orbitrol and just reconnected them to the new one in the same exact ports as he had them before! Moral of the story here is the hose routing diagram in the manual is not real clear so double checking the port locations is a good idea. I would hate to see you spend over a grand on a part that isn’t the cause of your problem. I also remember someone lapping the back plate you spoke of to get it back to flat. I’m not sure if I read that on this forum or saw it on YouTube or something.

 

[Dwellonroof]

Thanks for the explanation and the manual is not very clear even the hydraulic schematic from the Kohler engine vs the Kubota looks to me that on the pump/ steering circuit the Kubota should be the same as the Kohler.

 

[Dwellonroof]

I got to thinking that maybe the second line from the pump to steering is pressure also and the load sense valve changes direction or am I confusing myself??
View attachment 737214

 

[Dwellonroof]

 

[River Valley Landscaping]

I would think that the way it is setup in your situation is so the machine uses those two lines coming from the gear pump as both to/from depending on which way you are steering. Leaving the tank line to only let a little bit of fluid release when a shock is given to the system, as in steering left and all of a sudden wheel hits a rock giving the steering a jerk. Similar to how the drive motor would be. I have nothing to back up this line of thinking though other than common sense so I could be way off.