Retrofit hydraulics and PS on 716H

[jlasater]

So I spent the evening perusing the tech manuals online at simplicitytechpubs.com and noticed that the 716/7016 tractors evidently had a hydraulic option that also allowed the use of power steering. One of the two power steering options used a normal steering control similar to what's used in combines and the like, vs. the older style that used a hydraulic cylinder with the valving inside of it. Have any of you guys retrofitted the parts to put power steering on a 716/7016? Are we talking big bucks (over $1000) and are any special mods to the Sundstrand hydro required? Inquiring minds want to know. I haven't been able to track down the part number for the power steering system, but the manual listed it as a possible aftermarket kit.

[MikeES]

My friend took the hydraulic lift off from a 7790 and installed it on his 716H, made no changes to the hydro, and it works great. He just plug the hydraulic lines into the same place as they were on the 7790. He had to drill a hole in the side rail frame for the control valve lever shaft to poke through for the control lever. Everthing fit perfect including the hydraulic lines.

[UCD]

There is a difference in the pressure relief valves on a hydrostatic tractor with hydraulic lift and a hydrostatic tractor with out hydraulic lift. It will work just by just installing the hydraulic lift but it will not work right and is not good on the hydrostatic unit with out replacing the valves.

[jlasater]

Yes, the manual did refer to different valving in/on the hydro. Been looking around for the p/n for the power steering kit, but still no luck. The manual here describes two power steering units. One is called a Power STeering Control Unit, and the other is a Power Steering Unit. The first unit looks like the Simplicty #1692098 kit that has all the valving inside the hydraulic cylinder. I'm not finding a p/n for the second type of setup. [url]http://simplicitytechpubs.com/6767PRINT/PDF_files/TP_500_973_01_SV_SMA_Sec12.pdf[/url] shows both units.

[UCD]

I found 2 Power Steering Kit part#s 1691021 & 1692098 Both have the same diagram for Sovereign GTH-L 900 2800 7100 series and should work with out to many modifications but it doesn't show the control unit.

This is a diagram with the control unit for the newer sovereign & sunstar.

[jlasater]

Looking at the Sundstrand 15 service manual, it looks like there are two different pressure valves for the pump, depending on whether you run hydraulics or not. Am I right in assuming that you can simply swap the valving, remove the two cap screw plugs, and run hydraulics off the tranny? Granted, it's not a 35gpm pump, but it'd run power steering and power lift, right?

[UCD]

You change the relief valves for the pump and you can run power steering and hydraulic lift. that is how it is done from the factory. the only draw back is you loose power steering when you push on the clutch/brake pedal. That would not bother me as I have never used the clutch/brake pedal on my 7790. Maybe I should go push it to see if its not froze from lack of use.

[jlasater]

Being as how my 716 is missing the brake components, I don't use the brake/clutch pedal either :-) Although, I have greased the zerk on it just to be thorough. Haha

[jlasater]

Looking at the parts book, I too see two part numbers for the first system you showed, UCD. Do you have a part number for the second unit, and is the Sovereign that the second unit fits much different than the 716H tractor? The "control unit" on the first style of unit is represented by #27 in the diagram at the end of the hydraulic cylinder.