2001 Freightliner 12.7 series 60 pre egr. I have blown two water pump seals now. The first was about a year ago. It was a detroit pump with unknown miles on it. It just started leaking one day coolant from the weep hole. I replaced that with a gates pump. Now it is weeping coolant also. Have replaced overflow cap and pressure tested the system. Truck does not run hot or blow coolant out.