2006 2500 Cummins, 180K. I have a small coolant leak towards the front of the engine, right by the A/C compressor. I have replaced that small hose driver side, coming out the side a couple years ago. My original had failed as many others had. No leak for several years. Have replaced the water pump recently because that appeared to be leaking. But now I see coolant again. I see others have had failures on aftermarket ones, but it just seems the leak is starting below the water pump. I see the belt tensioner and the bracket for the A/C compressor are both below the water pump. Do either of those have a gasket that could be leaking coolant? Maybe it is the new water pump, but it seems to be leaking about the same amount as the previous water pump. That is why I am looking at other possible sources before replacing water pump again. Not the easiest area to see. Thanks!!

 

Check the bottom of your top radiator hose. I just found a pinhole leak on mine which would shoot glycol down by the water pump, was hard to find the actual leak.

 

I just had to replace my whole radiator :/

 

Still looking for more insight on this. I would like to rule out my question about the A/C mount and the tensioner, does anyone know if these open to the block when removed? If so, maybe I have a bad gasket.

Thanks

 

Tensioner does not have a gasket or opening to coolant behind it.