I have a B8200 4x4 gear tractor with Kubota FEL and backhoe. The tractor had the manual steering box which was a real pain when using the FEL. After the 2nd time the steering box broke I decided to go with hydraulic steering. I bought a rotary 4 port hydraulic valve and a hydraulic cylinder and fabricated all of the mounts. I ran the hydraulics from the 2 ports that are on top of the hydraulic block that were intended for the factory power steering. The steering works great now and I can steer with one finger with the bucket full. However, since I did this the FEL is very slow and after running a little while it doesn’t want to lift anything but the smallest loads. I have found that when it doesn’t want to lift I can hold the steering wheel all the way to the right lock and the FEL then has full power and speed. What could be causing this? So far I have installed a new hydraulic pump, new FEL valves, cylinder seals, and replaced the fluid, screen, and all the systems o-rings.
Homemade Power Steering Issue
- Thread starter MPope03
- Start date
I do not know your specific tractor so my comments are a bit generic.
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Your tractor has an open center hydraulic system. Flow is continuous and at low pressure until something blocks the flow and then the pressure increases to do the requested task.
This is why when you make demands on the steering system, the pressure increases and then you have high pressure for the FEL as an unintended consequence.
Usually, when there is one hydraulic pump serving say a FEL, 3 pt hitch and power steering, the system incorporates a priority flow control or flow divider to ensure the steering always has flow so you have steering but also to not pump the entire system output through the steering leaving nothing for the other systems.
Often you will find tandem pumps i.e. two pumps locked together with one serving the steering and the other FEL, and 3 pt hitch.
I think you need to consider incorporating a priority flow valve in your system
Dave
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Your tractor has an open center hydraulic system. Flow is continuous and at low pressure until something blocks the flow and then the pressure increases to do the requested task.
This is why when you make demands on the steering system, the pressure increases and then you have high pressure for the FEL as an unintended consequence.
Usually, when there is one hydraulic pump serving say a FEL, 3 pt hitch and power steering, the system incorporates a priority flow control or flow divider to ensure the steering always has flow so you have steering but also to not pump the entire system output through the steering leaving nothing for the other systems.
Often you will find tandem pumps i.e. two pumps locked together with one serving the steering and the other FEL, and 3 pt hitch.
I think you need to consider incorporating a priority flow valve in your system
Dave
Dave - Thank you for your reply, it caused a light to go off when you said my tractor is open center. When I connected the steering valve to the hydraulic block steering ports I had to remove the factory plugs. Both of the ports were individually blocked. Could this mean that the hydraulic block is a priority valve and I should have installed a closed center steering valve instead of open center? If so, is there a cheaper way to fix this than buying another valve? Like maybe putting in an adjustable flow restrictor in the steering hose?
North Idaho Wolfman
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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
No a closed center valve wouldn't work in place of the open center.
The real issue is as Dave pointed out.
The models with hydrostatic steering have a separate hydraulic pump section to to run the steering unit.
A priority valve will help but it won't completely fix the issue.
I would suggest either installing a second pump, you can run it off the front of the crank, or belt driven off the fan belt drive.
The real issue is as Dave pointed out.
The models with hydrostatic steering have a separate hydraulic pump section to to run the steering unit.
A priority valve will help but it won't completely fix the issue.
I would suggest either installing a second pump, you can run it off the front of the crank, or belt driven off the fan belt drive.
When I had my B8200 I added power steering by buying a control valve, cylinder, steering rod and wheel, and hoses from a Toro (I'm pretty sure) 20 Hp mowing machine.
I adapted the shaft so I could use the Kubota factory steering wheel. Used a plasma cutter to modify the support where the control valve set. I removed the pitman arm and steering box. Fabricated up brackets to mount the cylinder.
Hooked the hoses up and I never had any trouble with it....ever! It was easy to steer, and the loader always worked fine. Here's some pictures that may help.
I adapted the shaft so I could use the Kubota factory steering wheel. Used a plasma cutter to modify the support where the control valve set. I removed the pitman arm and steering box. Fabricated up brackets to mount the cylinder.
Hooked the hoses up and I never had any trouble with it....ever! It was easy to steer, and the loader always worked fine. Here's some pictures that may help.
Attachments
A couple more. You can see here I couldn't get the original rubber bushing to fit around the column correctly. I use some rubber cement to make one. That is the only thing that did not look factory.
Attachments
Thanks for all your input. I'm not trying to be dense, but the B8200 came with a power steering option and there was no extra pump. The hydraulic block has two sections and the FEL connections are obvious open center. The power steering ports are capped if it didn't come with power steering. The more I think about it, it seems logical that maybe I do need a closed center orital vavle instead of closed:
I have picture of the b8200 hydraulic block from the manual but I can't figure out how to post it.
- If I turn the steering wheel all the way in one direction the cylinder cannot go any further and flow is being blocked then the FEL will work with full power
- The ports on the hydraulic block are normally capped, with no damage to anything, so no fluid could be flowing from in to out - looks like the hyrdaulic block was designed for this
- With the power steering ports blocked, the FEL works fine
I have picture of the b8200 hydraulic block from the manual but I can't figure out how to post it.
Donystoy
Active member
Equipment
LX2610HSDCC, B/H, Loader, plus numerous other attachments. B7200 sold
When I installed the factory power steering on my B7200 over 30 years ago it included an additional hydraulic block that piggy-backed to the block where the loader hoses attach. It accommodated the pressure line that went to the push-pull valve mounted on the cylinder. The return line went to a port on the hydro- unit just above the PTO control lever.
Not sure what is in this extra block but I will try to ask the parts guy at my dealer. He is very knowledgeable and came from service.
I recently asked him if parts were available for this system and he said yes but probably mostly repair parts. I have to pick up some front axle pivot parts for my tractor in the next day or so and will try to get any info he can supply although might be difficult due to social distancing due to the virus.
Not sure what is in this extra block but I will try to ask the parts guy at my dealer. He is very knowledgeable and came from service.
I recently asked him if parts were available for this system and he said yes but probably mostly repair parts. I have to pick up some front axle pivot parts for my tractor in the next day or so and will try to get any info he can supply although might be difficult due to social distancing due to the virus.
I have exactly the same issue and I have the factory power steering and bf300-a FEL. What did you find out?
Here is a picture of the factory pump, I have same issue.
And here is the hydraulic block you are talking about with 2 lines going to the power steering on top:
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I had a bigger tractor years back that had a proportioning valve that looked similar. Here is the 8200 valve. Try turning the directional valve labeled here to the opposite position. I think that is what enables the flow divider function in the valve.
THAT IS *EXACTLY* THE VALVE I HAVE and nobody has been able to explain what the directional valve does properly... I didn't realize I was adjusting flow between the FEL and the power steering. I guess you can't have both?