<VV> Oil cooler removal

[David George]

Trying to replace seals for oil cooler to fix a leak. I have removed the four small bolts that go into the sheet metal around the cooler (the ones holding the cover and base on) and the large 9/16 bolt going through the right side of the cooler. While the right side of the cooler comes loose, the left does not. Do I also need to remove the larger bolt to the left of the oil cooler to remove it? I ask because before I put a wrench on it I want to be sure because it is very tight and looks a little rusty. I don't want it to snap off. I plan to soak it with some WD-40 or the like this evening. My shop manual does not seem to indicate that the left bolt holds the cooler on, but when I took the right one out and moved the cooler, it looked to be held down by the left bolt as well. Just wanted to ask for some advice since I have never taken the cooler off before. Thanks!

Dave