Anyone have any tips for hunting for a coolant leak? At idle, it does not leak, but if I run the truck and park it, then it starts to leak. It looks like it is leaking somewhere in the front of the motor, around the A/C unit. I spent 2 hours today looking for a leak but couldn't find it. It is really starting to *&^% me off. Anyone know what might usually go bad in that area? I checked all of the hoses and they all felt dry but i dunno....

 

The reason it does that is because pressure builds up in the cooling system after shutdown, because the cooling system is nno longer operating.
The water pump has a weep hole on the bottom that begins to leak when the seal/bearing begins to go bad in the water pump. That's all I know of in the front, besides the hoses.
The best way to check the cooling system is with a pressure tester which will allow you to pressurize the system without heating up the engine. Your current method can work also, it's just a bit hotter as you are trying to find the leak.

Chris

 

CHRIS!!! That makes so much sense now! I had the same thing happen on one of my gassers but it slipped my mind. Thanks for knocking some since into me haha. Is it hard to replace the water pump?

 

Dude, it takes longer to get the belt off and on than to change this water pump. 2 bolts and and O-ring. Best design I have ever seen.

Chris

 

What do you expect, it's a Cummins.

 

Well i started taking a second look at everything...It looked more like the thermostat because it was up high near the leak, so i replaced that. Ran it, still leaks, looked even closer at it and I am pretty sure it is the head gasket that is leaking now...Bummer, new truck, new work haha. I have never done a head on a diesel so this will be a new experience.