8011 hydraulic

Hi, new to the zetor world and this forum. I just bought an 8011 and it seems to have a very small hydraulic leak. The problem i have is i cant locate where i top up the hydraulic oil? So if anyone can help me find where this is i would appreciate it, and if its ordinary hydraulic oil that goes into it, eg iso46. I have ordered the manual for this tractor but it will be another weak before it arrives. thanks

there is a hole in the cab floor between gear stick and dif lock pedal. multi purpose oil is all i ever used.

To follow on from Zed's reply, its a 27mm hex nut with the dipstick attached on the bottom

Thanks for that guys, much appreciated.