Combines N6 pressure testing

[Dan]

Richard, What all was not working right on your hydralics or hydroIJ Did something fail suddenly or over timeIJ Make sure hydro is exactly in neutral when measureing pressure. I would install inline flow meter inbetween hydro and hydro filter so you can monitor flow to see what it is doing. Did you adjust replenishing valve pressure and replace it or did you adjust hydro charge valve and replace itIJ Did you find any junk in the bottom of your hyd. tankIJ Need a little more info and we'll try help out. Dan

 

[Richard]

Dan, nothing has actually failed. Clutch valve was replaced when we bought the machine 3 seasons ago and the pressures had not been re-checked since. I adjusted and replaced the replenishing valve and tried adjusting the hydro charge valve as well. local dealer today suggested, like you, to try a flow meter on the power steering line off the n1 valve in the valve stack. Do I need to undo the main drive belt to stop the hydro from starving or is that only when you check the pump by itselfIJ Agco rep. happened to be there and he said that the n1 master valve has been as source of trouble often enough. There was no debris in the tank when I changed the oil. Thanks for your time. Richard

 

[Dan]

Richard, You can tie flow meter into no. 1 valve to see that you approx. 5.5 gpm stays constant and if it don't you should look into the no. 1 valve. Use a long enough hose for your gauge so you can watch pressure from the cab while you are moving hydro handle back and forth to get your exact neutral. Pressure will be the highest in neutral and should be the reading you use. If you have someone in cab holding your steering hard one way you can turn the hydro charge adjusting screw in and out while watching pressure and set it at 75 psi less than charge pressure without holding steering wheel over hard. If you set hydro charge pressure to high it will be sending oil to hydro at all times even when not steering hard and that can heat your oil more than necessary. You do not need to unhook hydro drive belt to check your hydro pressures. Hope this helps. Dan

 

[Richard]

Dan, spent some time today adjusting replenishing relief valve and hydro charge valve. Seems like hydro charge was set high enough and replenishing low enough that the relief was always getting kicked out. Replenishing relief is now at 275 lbs. but hydro charge is at 580 non-steering and 540 steering hard. The hydro charge valve is backed out as far as is possible. When we initially found the bad clutch valve the mechanic doing the testing adjusted the compensator valve on the end of the main pump a little. Could I back that valve off a little and get my proper pressuresIJ It is the one closet to you when you stand beside the machine isn't itIJ Thanks again. Richard

 

[Dan]

Richard, Are you using the same gauge for both locations and do you have a long hose so you can monitor pressure from the seat while moving hydro handle to find exact neutral with the highest readingIJ I just wonder about your gauge or gauges at this point. let me know. Dan

 

[Richard]

Dan, I have been using two guages and have been able to see both from the seat. Something does some amiss though. At one point today both gauges dropped significantly. I tried bouncing the table a little and also the hydro lever back and forward a bit. The guages both came up again, the replenishing to 275 and the hydro to 580. Could it be I have a sticky valve somewhere and I am just chasing my tail aroundIJ Thanks Richard

 

[Dan]

Richard, I was starting to think hydro charge valve but that shouldn't have any thing to do with pressure when not steering hard. Did you hook a flow rater in to see if flow is proper or moving aroundIJ I wonder if you should switch your gauges around to see how they read when switched positions. Talk to you later. Dan

 

[Richard]

Dan, I removed the hydo charge valve today. Disassembly showed some small pieces of scrap inside. The piston inside was also stiff and very hard to remove initially. I'll let you know how it goes when I get it shined up and reassembled. later Richard

 

[Richard]

Dan, I think we have figured out our combine. We re-installed the hydro-charge pressure and went back to the original replenishing relief valve. I thought that the pressures between steering and non-steering mode weren't recovering properly but it seemed that when we steered that it moved the combine just to enough to move the hydro lever off of neutral. When I realized that it seems as if all systems are reacting as they should be. I certainly appreciate all of your input. Thanks Richard