hi there any ideas on this one. we got a great Case 956 XL always worked well on mowing, all clean rads, coolant etc. This year the pressure built up in rocker cover and bust the gasket and now its overheating, but only when working at normal full revs

Removed thermostat, water pump seems ok but not sure if its just got slightly weak.
Aboslutely no sign of any problem with engine power, nor oil in water and water in oil, so no crack.
Cleaned filter etc. Put new rocker cover checked breather.

Also loads of steam comes out from breather underneath when working generally

Are we missing something obvious or what . Some of the diesel lines seem a bit leaky and we have to replace but would that do it, fuel shortage ?

just wouldnt go round at the right speed.

Or general debility
any thoghts /experiences