Thanks for the replies. The radiator is well above the thermostat, so thats no problem. The problem I have is I dont have anywhere high enough up to put the expansion tank for it to be higher than the rad and the thermostat housing. All tractors I have worked on just have the radiator, no expansion tank, thats why I was considering it. I presume that as you dont fill the radiator until it is coming out of the cap, then it allows for some expansion. The radiator is considerably bigger than the standard tdi radiator, maybe bigger than the rad and expansion tank combined, so I think it will probably be OK
On the tractor, the overflow pipe just goes to the floor, no recovery tank. Do you think I need the recovery tank ?