Rear Hydraulics not working

JHK Farms · Mar 14, 2012

I received a 2000 NH 3415 with 218 hours from my brother's trust after a 2.5 year court battle by his 3 day bride. I got it running just fine, the rear hydraulics seem to work fine. Then the hydraulic pump starting grawling/whining. I checked the hydraulic fluid and found it had water in it. So I drained the Hydraulic fluids, which also include clumbs of hydraulic fluid/trash at the end. Rinsed the reservoir with diesel fluid several times and drained, then replaced the hydraulic filter that I purchased at the New Holland dealer and added the correct Hydraulic fluid. The rear hydraulics still do not work. What am I doing wrong? Do I need to bleed air out some where? The hydraulic pump is running smoothly. The tractor does not have a FEL. Thanks, JHK Farms

jinman · Mar 14, 2012

Do you have a steep hill? I think I'd be tempted to park with the nose down a steep hill to see if that helped. You probably have an airlock and the pump cannot self-prime. With water in the hydraulic system, your HPL valve might be stuck, but that's just a remote possibility. I looked at the NH diagrams and do not see a screen inside the reservoir for your tractor. Sometimes gummy residue can clog a screen in the suction pipe going to the reservoir, but I don't see one on your tractor.

JHK Farms · Mar 15, 2012

Thanks Jim I will Check that. Waht I found is the hydraulic reservoir takes around 8.5 gallons empty? Let you know waht happens. But I think it is getting hydraulic fuid to the rar because there's a little box on the return line that you can unbolt. On top it has a decal with what looks like a finger punching a button on a calculator. When I remove that Bolt/plug looking bolt, hydraulic fluid comes pouring out. Hoby

jinman · Mar 15, 2012

Hoby, I think that "little box" is in the pressure line instead of the return line. The box sounds like the system diverter/pressure relief valve. The little book is telling you to refer to the Repair Manual for servicing/shimming the relief valve. If your hydaulic lines are two sizes, the large one is suction and the small one is pressure. The diverter block does have a return line attached because fluid from your relief valve goes through that line to the reservoir, but its main function is to regulate system pressure and to divert flow to a loader if installed.

JHK Farms · Mar 17, 2012

Jim, I parked it on a steep hill over night, must have been an air lock. When I started her up, the rear hydraulics came up. No noise from the pump or any place. Now to clean her up and put her up for sale. I just don't need a third tractor at this point. Thanks for all your help.
Hoby