antifreeze issues

[99ramtruck]

i flushed my radiator and refilled it with prestone. mixed at 50 50. first my water pump goes about three weeks after the flush. and now my heater core goes bad. i smell antifreeze when i turn on the heater. but i dont seem to be loosing any antifreeze and there is none inside the truck. how hard is it to replace the heater core in a 99 ram 4x4. i dont want to get into the project and find out i cant finish it. or maybe it is something else. anyone have anyclue or suggestions. thanks for the help

[mopartec]

i`d recamend taking it to a shop the complete dash has to come out and the ac system must discarged to remove dash then be recharged after reassembling.

[99ramtruck]

is there anything that can be recommended to possibly fill the hole in the heater core. i already tried bars leak.