Loader FX28D with FEL problem

[Ben755]

The Koyker loader on my FX28D tractor developed a problem yesterday. Instead of lowering when the joystick controller is pushed forward, the loader now raises. Only the lowering functions fails - all the other functions work (raise and tilt). This occurred once before after I had removed the 3-point assembly to replace orings and a seal. However, the FEL started working correctly after I adjusted the valve held in position with the left 3-point lift arm cap plate. (shown in the pic below). This time, adjusting this control valves didn't help. The 2nd pic shown is a valve control under the driver's seat which also has a significant effect on the FEL and the 3-point lift. Apparently, the these two controls vary the hydraulic fluid and pressure to the FEL and 3-point lift. The hose hookups (pressure and return) to the FEL are routed through the 3-point housing via metal banjo connections. The below seat valve effects the pressure line going out to the FEL. I don't know if this loader lift problem is in the FEL joystick controller or the the two valves described above. Has anyone experienced this problem, and can anyone explain the exact function and the proper setting positions of the two valves ?

 

[runningbird]

have you moved the slide in the 2nd picture. what it does is divert fluid to the connectors under your right foot panel, and that is what feeds your loader control. it does not look like it is all the way in place. when you start the tractor does it seem to be lugging, if so you have that slide in the wrong spot. also double check the quick connects under the right foot panel.

 

[Ben755]

I've moved that slide control through it's entire range with no improvement. Before the loader raise problem occurred, the FEL worked best with the slide sitting in the far left position - moving it right toward center would stop the FEL from moving at all.

 

[runningbird]

I would disconnect and reconnect the quick connects under the right foot panel.

 

[Ben755]

I replaced the quick connects with threaded couplings some time ago due to leakage from the quick connects that new o rings didn't fix.

 

[winston1]

Was this last occurrence sudden and with no changes on any of the system? Maybe the loader control valve? How hard to change function hoses on the loader and see what happens,

 

[Ben755]

When I started the tractor this morning, I noticed that the 3-point lift was dead - no movement at all as if there was no pressurized fluid on the piston head. But, back to the FEL problem....
I temporarily replaced the return hose from the FEL control with another hose and routed it directly to the opening to the fluid sump (used for adding hydraulic fluid). Started the engine and checked the FEL - it work perfectly, up and down. Apparently, there is a blockage somewhere in the return line. So now, I left with finding the blockage and determining what's happeded to the 3-point.

 

[winston1]

I have no idea just how you are plumbed. Is your loader valve using a power beyond? Does the fluid go through the loader valve before going to the 3 point?

 

[Jtullis13]

Confused... I'm not sure how your tractor is plumbed either. I follow what you are saying but a flow diagram would be helpful. Sounds like an O-ring or seal is out. Or could be a flow problem to do possible linkage with that lever if there is linkage used with it? I don't know. Can you feel fluid running through the hoses when manipulating the joystick? And like Winston asked, do you have PB?

 

[Ben755]

There is no service manual in English for the FX series tractors. With my limited knowledge of hydraulic systems, I can only show you how the hydraulic flow appears to be plumbed based on my experiences in dealing with the problems that I've presented in this forum. The diagram below shows the fluid flow from the pump to the 3-pt cylinder head cap plate. The pressure flow to the FEL is routed through the 3-pt housing and out to the FEL. It appears that the FEL problem is caused by back pressure on the return/suction line. I've removed and checked the lines and couplings from the 3-pt to/from the FEL and found no constrictions. I suspect the problem may be in the below seat valve on the FEL return line. There are several valve assembly modules on the 3-pt housing including a somewhat elaborate module (36 parts - o rings, springs,etc) bolted to the base of the housing when it bolts to the transmission - only God and manufacturer know its functionality.