I haven't long owned my international 444. I recently bought a topper to top my field. I was running for about 15/20minutes on Tuesday before my core plug blew out. I put the core plug back in with engine sealer and tried topping the field again today. But again I was running for 15/20minutes and noticed water/steam coming out of the radiator cap. So I stopped the tractor as I did not want to do any further damage. I've flushed the radiator out with a hose. The radiator seems to be clear. Any advice on what my problem could be? Thanks in advance