Hi I have a 540 very good machine well liked by toolmakers and trade shops,hydrauics usual problem is dirty or choked filter in oil tank,the hydraulics do not look to be very complicated,one problem can be air in system after machine left standing ,remedy is to let table operate over full travel for a few minutes ,this is recomended in the handbook.Golden rule with grinders do not strip any part unless it is essential,as it is all too easy to get particles of grit in the works.If you hand feed the table
the slide ways have to be lubricated with oil can as during normal operation there is a bleed off the hydraulics to lubricate the bed ways,under the table there are two pockets which catch oil that drips from the slides,clean these out as they attract airborne grit and can turn the oil in the pockets into a grinding paste and damage the slides.wheel nuts are left hand.A j and s service engineer once told me that lubrication nipple for the cross feed slide hand wheel must not be greased ,it must be oiled,very commom problem cross feed stiff,usual cause filled with grease. The automatic feed has been found to be assembled incorrectly,which can cause the feed too operate when the table reaches one end of its travel,it should operate when the table reaches either end.hope info is of help.