Hey all, looking for any advice on my issues here. I've got an 81 diesel caddy. Currently overheating and I'm not sure where to look next. It's always done fine, even when I lived in Arizona (I'm in SE Ohio now). Last summer on a trip to Pittsburg it started overheating climbing all the hills in West Virginia. I had just replaced the timing belt that winter and had been putting off doing the water pump, and had seen no signs of head gasket failure (no oil in coolant or vise versa). Replaced the water pump with a part I got from a friend that looked new, labels made in Germany, looked like a newer appropriate pump, and a new thermostat. I tested the thermostat in water and it opened @180f .the pump has one of those weeping holes and immediately I saw coolant leek out of there. Also since doing this my running temperature is up a few ticks from where it used to be, though it didn't overheat and tended to stay in the middle of the temp gauge. Well, it's overheating again and I just don't know if I should replace the pump again? Is a leak in the pump a definite failure? Seems odd it was brand new but maybe it was defective. I'm other questions are just where else to look. As I said I haven't notice anything bad about the head gasket and I replaced the radiator about 5 yrs ago with a cheap one. Can I test it's performance? Coolabt system was flushed by running a hose in through the resevoir when i installed the new pump. Also, it does run a notch or so cooler when I run through the heater core if that is helpful. Thanks!