I am trying to figure out why I have had a coolant line failure to the water to oil cooler which is located on the passenger side just under the exhaust manifold. This is the second one in 2 years, this time I was pulling up a mountain the tranny downshifted and I told my son I thought I heard a pop. I kept my speed loosing no power and mpg(17). This time it didn't blow off just looks like the o-ring failed. I had my tranny rebuilt awhile back with some work done to the valve body. Dodge garage tells me it is just a cooler and that this no large amounts of pressure on this line. I relaced the last one with dodge geniune parts so what the heck am I doing wrong.