John Deere 35c

Hello everyone. I am new to this forum and in much need of some help. I have recently bought an early 2002-2005 John Deere 35c mini excavator that has some issues; primarily all the original electrical wiring its gone, but someone managed to re wire all the basics, the machine runs, basically is an ignition switch and analog hour, battery, oil pressure, and water pressure gauges. Hydraulics is my big concern, like I said the machine runs and digs but it lacks power on swing motor, it swings really slow either way; left or right on a 360 turn. Another issue is that left track is really slower than the right one; at the point that it stops if right track is not moving, same going forwards or reverse. Finally, hydraulic oil gets pretty hot (have not measure temp yet but oil tank tube lines get hot within minutes of use), the hydraulic controls on joystick turn pretty hot at touch too. I have done basic maintenance like engine oil change, cleaned and drained radiator, fixed most of hydraulics leaks and greased most of grease points. I can work around the machine but my knowledge is limited, that is why I am looking for advice, tips, tricks or diagrams anyone can provide me with, did buy a parts and service manual, but is not of much help, it lacks electrical and hydraulic info, but is someone needs it I think I can share it too. Bought the machine at a good price, trying to save me some money here, thanks in advance for your help. Best regards Henry Sanabria