3-Point Hitch 3-point Hydraulic cylinder has flow by

[Ben755]

Yes, the drawing for the FX28D shows the parts going in from the inside of the front plate - no way, the opening from the inside in much too small. I'm assuming that Yanmar made two different lock valve assemblies for the FX28, one without the the ball & spring setup and the other with it. I notice that Hoye shows both breakout drawings for YM1500 on their web site (image below) . So, I pushed the valve (no.9) in from the front, small end first. Well, I put the box blade on the 3-point and it raises and lowers. But, the lift arms still have a small drop and jump motion, indicating fluid loss somewhere. The lock valve in closed position will freeze the lift arms, but they slowly drift back down (about 4 minutes). I slightly scored the end of the no. 9 valve which may be causing the problem, or the piston seal is not working. I may just have to live with it.

 

[winston1]

Yes, your leak down could be coming from the control valve or a relief valve. Could be trash in one of them or possible bad o-ring in one of them.

 

[clemsonfor]

Or like in my case just wear. I replaced everything I could O ring wise in my 3pt valve and it will still slowly leak down after I put the new O ring on the piston and the o rings in the valve.