3 point hitch will not lift on l2900

[gunman]

My l2900 was lift ok with the loader attached but took it off and the 3 point has quit .I turned the little slotted control on the front valve body and it worked but did not lift all the way up.Does anyone know if it has a screen or if the filter might need changing ,the front loader works fine when attached but the 3 point will lift without load but will not lift my mower at all.The tracter looks like it was never serviced.Thanks for any help.

 

[Bulldog]

How many hrs on the tractor?

 

[gunman]

Thanks for the reply it has 1410 hours on it and the filter looks like it has been changed.I going to try and check the control there where it connects back together when i turn it off then back on it starts to lift then quits.