4210 Hydraulic Issues

mike48130 · Dec 5, 2017

This tractor is new to me, so no real history, 1600 hrs. The loader and rear lift seem to not have any power. It gets worse when the tractor gets warm. I put a pressure gauge on the loader connections, and they are not constant. It seems if I play with the controls, the pressure will get up to over 2,000, but if I just hold it I get only about 1,000psi or less. The bucket curl seems to have a dead spot in it and can't ever get to the 2,000 psi. I put the pressure gauge on the power beyond, and I only get 750 psi. It seems odd. I put a new oring on the pressure relief valve and no change. I pulled both pumps and rebuilt them since the tractor has 1600 hrs. There was some wear on the pump internals at the inlet side of the gears housing, more than I normally see when I rebuild pumps so I put new bushings in as well.

I ordered some fittings so I can put the pressure gauge directly to the pump, but not here yet.

I pulled the valve off today and the spools look like they are brand new. They are tight, and no scratches, scuffs or wear. It ha the 300x loader, so it is later than the tractor, so It was added later in it's life.

I scoped the valve and saw one area that may look like a crack. There were some casting lines, but this one area looked like a crack. I will attach the pictures. The pictures are looking into the pressure relief valve port.

Any thoughts or comments would be appreciated. I can't believe the valve would be cracked since the 4210 is 2150 psi vs. 250 psi on the 4310 and 4410 with the same valve. Anything is possible I guess.

mike48130 · Dec 7, 2017

So for an update, I cleaned the PRV really good and put on new O-rings and backer rings. I put it all back on, and got it to adjust to 2300psi at the PB port. The loader now will lift the front wheels off the ground. It is in the garage so I don't have the bucket on, but it lifted. I need to put the seat back on tomorrow, and try her out.