mf 135?

During the long freezing spell this winter I went to check my MF 135 was OK. I keep it inside a barn. I started the engine with no problems and let it run for about 10 minutes whilst I went to get a cup of tea. On returning I found water coming out of a crack in the upper part of the engine block (fine crack 2" long - looked as if it may have been sealed previoulsy before I bought second hand about 5 years ago). I have tried to fill with metal sealsnt but water now appeard to be cascading doen from other parts of this top block. I am not wholly mechanically minded and use the tractor to do basics on my small holding - like topping and harrowing but little more. How do i fix..can I get help. I am in East Yorkshire, England