5040 allis chalmer farm tractor

[arctel]

I just purchased a 5040 allis chalmer farm tractor year model around 1980, it is a 9 speed with hydrolic hook up

the problem is the lift will raise sometimes and sometimes it will not when this happens the hydrolic will not work either
can someone tell me if this tractor has a hydrolic filter? if it has more than one filter for the hydrolic and where
the filters are located

thanks