oil contamination in header tank

[a j motors]

we have got a transit 140 t 350 in the garage with a gearbox problem and we have noticed oil contamination in the water header tank does anyone know if this model of transit has had any oil cooler or head gasket problems the van as done 280000 miles and not been very well looked after

[Frag]

Oil cooler is part of oil filter housing assy & common for failing.
Unless its been repaired but not flushed enough previously ,
be aware that hoses will perish then fail also if oil has been in cooling system any length of time......

[a j motors]

THANKS FOR ADVISE I WILL CHECK OUT OIL COOLER IN MORNING