Hello everyone I am a new member & looking for a little advice regarding a 1998 model toyota 1.50 ton forklift I am unsure what the model is but believe it is a 2 litre petrol.

This forklift has done only 600 genuine hours, I have only purchased it recently, I checked the dipstick a couple of weeks ago & found that it was overfull, I drained about 9 litres of oil out of it before it was down to the correct level, I checked the level on a daily basis for a few days & all seemed ok, anyway checked it today the oil in the sump seems to have increased to where it was a few days ago before I drained it prolly close to 15 litres of oil I noticed that the hydraulic oil is very low & believe the hydraulic is somehow mixing into the engine oil is this possible? or common what maybe the cause? there are no oil leaks coming from the machine at all. would appreciate any assistance thanx.