OIl leak in SK 160

Hi, does someone have service or repair manual in pdf for -97 US made Kobelco SK 160 LC ser nro YMU1372 I have problem with hydraulic leak somewhere, the leak perform itself so that oil start to come between the line in turning device below upper frame from tops side either the rotation oil feed or drive motor thru shows no leaks external it drives and turn still normally, but oil comes out so that 40 liters in two hours come out the digging wok and perform well, no loss of power I would like to look the hydraulic schematics and how to uninstall Local importer does not have manuals for this old machine, and was not very co-operative to order it from factory would need good advise and some help to locate manuals Pekka