case 195 power steering
Posted July 12, 2010 - 09:36 PM
Posted July 13, 2010 - 04:37 AM
I am not the best with hydraulics,but someone will be along after a while to help you.
Posted July 13, 2010 - 05:24 AM
Posted July 13, 2010 - 07:38 AM
Essentially, you were on the right track with your installation but you did not recognize one key factor.
Hydraulic oil is lazy. It does not want to do any work if it can be avoided so it always takes the path of least resistance. When you put the Tee in the pump's output line, you gave the oil a choice of which direction to take. If you turn the steering wheel, the oil senses that you are asking it to do some work. If taking the other path through the travel valve is easier, then that's the way the oil will go. That leaves you with little to no oil available to turn your front wheels.
The solution is to remove the Tee fitting and install a priority flow valve.
Here's a link for you to see them. Steering Priority Valves - Sauer-Danfoss
These valves are available in two forms. Fixed and adjustable. If the power steering pump you used, needs 3 gallons per minute to be happy, then you need to obtain a fixed priority valve with the 3 gpm rating. Buying an adjustable valve will allow you to scale back the flow to the steering pump until it is unhappy and then you can dial it back up a tad until it works smoothly.
Priority flow valves are designed to steal a fixed amount of oil from the pump output all the time. The problem with that concept is the fact that you lose that output for all other functions that happen after the priority valve. In other words, if your pump currently puts out 8 gpm at zero PSI and you put a 3gpm priority valve in series with it, then the rest of your system will only see 5 gpm from now on. If you intend to run a rototiller, then that could be a problem but if you have a loader on the tractor and all you do is loader work, then the worst that happens is that your travel speed isn't as fast as what it was before the priority valve was installed.
On the other side of the coin, by installing the priority valve, your power steering pump will always receive 3 gpm from the pump and therefore, you will always have power steering available to you. Another way this problem is solved is by changing to an integrated dual pump. The lead pump puts out 8 gpm for the hydraulic system and the second pump puts out 3 gpm that is dedicated to the power steering. However, these are expensive pumps and you don't have the room between the engine and the dash pedestal to accomodate one anyway.
The final option is to belt drive an automotive power steering pump on the side of the Kohler and use that to feed your power-steering.
Nobody said it was going to be easy. :madhop:
Posted July 13, 2010 - 09:36 AM
Posted July 13, 2010 - 09:38 AM
There are power beyond orbitrols that can be used as well.
You will use oil in the steering only when steering and have full flow to the traction when not steering.
Posted July 13, 2010 - 10:56 AM
Thanks for the replies. I contacted Sauer Danfoss and he explained that putting another pump on the front may be the easiest. You are right nothing is ever easy. lol
I don't know why he would tell you that.
The 648 model came standard with power steering and it used a priority valve to take care of the steering needs. He should have discussed this with you further and made a recommendation on which valve or valves would do the job. This isn't rocket science here. You need a priority valve that has 1/2 inch ports on the IN and OUT sides plus a third port that will deliver the needed flow to the steering pump.
I find it very annoying when you call up a company as large as Sauer-Danfoss and can't get the sort of help you came there to find. I would call them back and request to speak to someone with a technical background. Tell them that your system's pump only flows 9 gpm at zero PSI and the working pressure is 2000 PSI. Tell them you need a priority valve that will adjust from zero to 4 gpm that will work with the flow rate mentioned and you also want a list of SD dealers in your area, as well as the catalog numbers for any products suggested.
Posted July 13, 2010 - 11:04 AM
Posted July 14, 2010 - 09:04 PM
Posted July 28, 2010 - 06:56 PM