Weak FEL on 4220D

[Gary Fowler]

I have a Yanmar 4220D with V3 FEL. I have had it a couple of years and when I first got it, the FEL had lots of lift/curl capacity. It would actually lift the rear wheels off the ground if you hung the bucket teeth under a tree root. Now it is very weak and will hardly put any pressure on the tractor even in the curl mode. The 3 ph still works and picks up lots of load. I dont have a pressure gauge to hook on to see what pressure it is putting out. Anyone have any idea what could be wrong with this. It looks like the joystick might have some sort of setting on the side, perhaps a relieve valve or something, but I have not touched it as I am not sure what it does. It is to the far left of the handle and has a hex key adjustment with a lock nut to hold it in place. Could this thing have become weak and need adjustment?

 

[Smoody]

The screen mesh filter could be dirty, have you checked that? Im not sure put that model may have a spin on filter as well. How many hours have you put on it and has the hydraulic fluid ever been serviced? You should change filters and fluid every 500 hours.

 

[Gary Fowler]

I havent cleaned the screen in about a year but I only have about 30 hours on the tractor. I cleaned the screen about 4 times and changed the filter 3 times when I first got it because the system was contaminated with grey mud of some type that stopped up the screen and the spin on filter. I finally got this clean I think. That pump also works the powershift clutch so when it stops up, it wont go either. The same pump works all the hydraulic including the 3 ph and it still works fine. Just the FEL is weak. I can still pick up a 850 pound disk with the tractor on idle with the 3 ph.