B7200HSTD - What else do I need for power steering?

[Creig]

Hello all,

A while back I jumped on an eBay auction for the difficult to find portion of a factory Kubota power steering kit for the older B series tractors. Namely, the hydraulic cylinder, drag link and the mounts. I even managed to get the seller to include the rubber lines and the two steel lines that cross over the tractor and attach to the top of the hydraulic block.

My question is, if I can find a source for the factory three steel hydraulic lines and hydraulic block from a B8200, will they be a direct bolt-in on my B7200? I believe that the B8200 block was used on the B7200 as part of the upgrade kit because it has the two power steering ports on top. The stock B7200 block does not. I'm just not sure if the three steel lines from the B8200 would be direct bolt-in replacements for the steel lines on the B7200. Or would I be better off going some other route to get the fluid to/from the cylinder?

I'm almost certain that I've seen pictures of B7200s with factory PS that have the B8200 hydraulic block. But the stock B7200 block has one line in from the pump and one line out to the 3-point whereas the B8200 block has one line in and two lines out?

Thanks in advance for any thoughts/suggestions.

First attachment - B8200 hydraulic block diagram
Second attachment - Photo of B7200 block
Third attachment - Cylinder, drag link, brackets and soft lines I now own
Fourth attachment - Hard lines (I own) and B8200 hydraulic block and input/output lines (I don't own)

 

[Creig]

Three additional pics:

First is a screen grab from the WSM showing the B7200 block and lines.
Second is a shot of what I believe is just the bare B7200 block.
Third is another different angle shot of the B7200 block.

 

[North Idaho Wolfman]

What you would need to hook it up to the B7200 diverter block was an add on block.

The b7200 block is power in and power out no provision for tank/ return where the B8200 block has that provision for tank/return.
So no a B8200 block is not going to be the same hook up.
I do believe the Power steering style for the B8200 was different in that it used an open system (power in, power out).

The steering system you have is a closed loop system, it has power in and tank/ return out.
That style of power steering requires the block to divert fluid on a priority level as needed to make it work. (One of a kind setup)

Now as far as just adding it into the lines, you can't do that as it's not a open loop system like the rest of the tractor, and doing so would make the rest of the hydraulic system inoperable.

Here is the add on block and the connections:
P/N 96319-37030

 

[Creig]

Yup, that's the part and diagram that I couldn't find. Thanks NIW! I suspected that it was going to be something like this, but hoped not. There certainly are a lot of differences between the B6200/B7200 and the B8200 despite being from the same era and of similar HP.

Looks like my next step will be to go over the diagram and see which parts are still available and how much it will cost to source them. These power steering kits are incredibly hard to come across, even for the B8200 which has the ports already built into the hydraulic block. The odds of me finding the B6200/B7200 add-on block and return fitting for sale by someone would be beyond reasonable hope.

 

[Creig]

As an inelegant alternative, I could probably also do what this person did and tap onto the supply line and plumb a B8200 hydraulic block to it in order to get the supply/return ports for the power steering.

 

[North Idaho Wolfman]

I don't know why they even bothered with the b8200 block (not that the block is wrong it's they way they connected it) .....
What they did was the same as just hooking it to the block on the b7100.

There is no priority valve use and there is no return line use, sorry but that's a stupid setup, waste of money.

I can also tell you that the fittings were forced into the block as the outputs on a b8200 for the PS are banjo bolt fittings and they have used other style fittings.

I even more surprised that it works at all.

If you want to spend the time to repipe and swap out your B7200 block to a b8200 block, you'll need to make or get an adapter for the fill port or better yet add a return line that would put return fluid right back into the suction line which if you look at the b7200 block it does that out the little hose that goes out the front of the block, an no that small hose is too small for a b8200 block to be used as he return.

The return line becomes very important to this block because it returns fluid back to the system with no back pressure which the relife and priority valves needs.

Now after doing all this, I still can't say for 100% certainty that it will work properly for your add on PS unit, but it won't hurt either.

I looked around for a B8200 Block, one on ebay at $499.99 and another 149.99 for the lines makes this one pricey change out.