The mounting bracket for the stock coolant expansion tank on a 1983 diesel Vanagon is prone to forming stress cracks and leaks in the plastic tank, due to the way it attaches to the bulkhead just forward of the battery platform.
During the course of an engine replacement, I upgraded to a complete set of silicone coolant hoses. These new hose diameters necessitate using a coolant expansion tank from the 1986-1991 gasoline Vanagons. While these tanks are of a better design and more readily available, they will not fit into the stock 1983 diesel mounting bracket.
So I took the opportunity to further improve things using a tank mounting bracket from Rocky Mountain Westy. This design provides better support for the tank, eliminating the stress cracks.
Unfortunately, the original tank mounting flanges on the bulkhead interfere with the surface mounting of the new bracket. I suppose one could simply bend and hammer these flanges flat, but I generally avoid such permanent modifications and molestations to original bodywork.
So I made a short stand off to fit between the flanges on the bulkhead, and to extend the mounting surface. It’s just a short section of one-inch (25 mm) square tube stock, about 5.25 inches (135 mm) long, with three bolt holes drilled though it. I spaced the holes in order to utilize the bulkhead’s existing slots, requiring only one additional hole to be drilled in the bulkhead.
These same three holes must also be drilled in the mounting flange of the new bracket, though you may find that one or two of the bracket’s existing holes can be used.
Install the bracket with stand off, mount your new coolant expansion tank in the bracket, and connect your hoses.