2404 hydraulic pressure

I have a 2404 and the hydraulics only have pressure when the 3 point I at the very top squeeling the pump as soon as u move the lever down enough so that pump stops squeeling the pressure drops to 0 psi. The result is the power steering doesn"t work. I was curious where is the pressure relief at and would that be what it sounds like? Thanks for any input.

(quoted from post at 02:53:43 12/06/09) I have a 2404 and the hydraulics only have pressure when the 3 point I at the very top squeeling the pump as soon as u move the lever down enough so that pump stops squeeling the pressure drops to 0 psi. The result is the power steering doesn"t work. I was curious where is the pressure relief at and would that be what it sounds like? Thanks for any input.

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The squeal you are hearing is the relief valve opening. The linkage must be adjusted wrong or you would not be able to put the system on high pressure with the hitch.

If you do not have steering unless the the system is forced to open the relief valve, your problem is with the priority flow divider valve for the steering. The valve should be the first place the oil goes to when it leaves the hydraulic pump. The valve should separate off about three gallons of flow for the power steering. The rest of the flow should go to the hitch and remote control valves if so equipped.

That was my first thought also so I took that apart and it apeared to be fine. Everything inside the valve looked very good no scars and fight really well. When the tractor is running and the 3 point is not topped out it has 0 hydraulic pressure. Maybe I am not understanding the system right.

The hydraulic system is an "open center" type system. That means that the oil leaving the hydraulic pump goes through the various valves and then returns to the reservoir. As long as no valve is putting a demand on the system the oil just returns to the reservoir and you will have no pressure in the system. When a control valve is moved the oil is diverted through that valve to what ever is attached to it, a motor, cylinder, power steering, etc. The pressure will then rise to whatever is needed to move the cylinder or motor and no more. If a cylinder should reach the end of it's stroke so that it can move no farther, the pressure in the system will rise until the relief valve opens. At that point you will hear the squealing caused by the oil escaping past the valve. That will be the maximum pressure the system capable of delivering.

If your power steering works when the system is on high pressure, caused by the hitch system, but not working any other time, the steering system is working but not getting the priority flow it needs. The priority valve works on flow, not pressure. The steering system is also an open center system so when no load is placed on the steering there will be no pressure rise there. However, when demand is placed on the steering system, the pressure will rise, but only in the oil that is flowing from that side of the priority valve. The remaining flow to the hitch will still pass out of the valve with no rise in pressure.

What it sounds like is happening is that when you activate the steering the flow through that part of the system stops and all oil flows to the hitch. When the hitch valve causes the pressure to rise it is also rising in the steering system to allow it to work.

You are a big help Alan. I think I may have my trouble figured out. I bought the tractor as is and they put hydrostat steering on it and if I am correct hydro steering needs constant pressure to operate correctly. I may have more trouble also though because when the oil comes through the priority valve it is purging. Even when the 3 point is topped out the steering still does not work. I am gonna keep after it surely I will eventually get it. Any further ideas will be a big help. These old tractors are fun to learn about but they also get aggrivating sometimes.

Owen I opoligize for my last post. I called you Alan I am posting this from my phone and I read it wrong.

Relief should be 1650 psi.

CT

The power steering does not need constant pressure but it does need constant flow. The pressure will vary depending on the amount of force necessary to turn the wheels. The flow needs to remain constant over the whole pressure range.

Is the steering system that was added the original equipment setup or is a an after market system?

Owen I honestly don't know what it is I was told it is what is on the 504 model tractors. I got an I&T manual on monday but haven't had time yet to look and just see what I can find out from there. I know what is on there has a 2 line steering motor and what I would call a diverter type valve that puts the oil into the proper sides of the cylinder. I wonder if a 4 line motor and do away with the diverter would be any better. Another thing is since the oil isn't a constant flow as I previously mentioned would that priority valve be the place to start on that? I feel like I need to have a good oil flow before anything else. I am bout willing to try anything at this point. I bought this tractor because it has a loader and we are suppose to get a pretty good amount of snow this winter. Thanks Owen and everybody else who has had input.