[C320-list] Heat Exchanger Removal - Perkins M30

[Dave Hupe]

 Bob-
I couldn't figure out how to break loose all 4 nuts on the exhaust elbow when I did my job, but since my emphasis was primarily on replacing my bad heat exchanger tank, it worked well for me to remove both the tank and elbow at the same time and then dismount the elbow from the tank in my garage.  Reinstalling my new tank with the exhaust elbow and wet exhaust hose already attached to it went pretty easily to slide it into place and seat the hose onto the muffler nipple without a lot of twisting/stress. However, if you DON"T have a reason to remove the tank itself, maybe look/try very hard to see if you can get the exhaust elbow off (maybe removing something else fairly easy) by itself as mentioned by Mark Cole.
As Mark mentioned a little heat on the wet exhaust hose and rubber end cap (and dish soap lube) during reassembly helps a lot. Also, consider alternatively using a more flexible replacement hump hose from Catalina Direct between the exhaust elbow and the muffler.  This hump hose  https://www.catalinadirect.com/index.cfm/product/2624/exhaust-hump-hose-2-id-x-6.cfm  will work, but you will also need the fiberglass splice available https://www.catalinadirect.com/shop-by-boat/catalina-350/engine/exhaust-system/exhaust-hose-fiberglass-splice-for-2quot-hose/ and a very short piece of regular 2 inch I.D. wet exhaust hose to fill the entire (although short overall) length between the muffler and exhaust elbow. 
I am positive my exhaust elbow had never previously been replaced.  I was amazed how clean the inside of my exhaust elbow and the exhaust manifold outlet on the heat exchanger tank were (probably due to my freshwater situation). Note .... After comparing my new and old heat exchanger tank exhaust outlet areas (where the exhaust elbow mounts), I can see where people may misinterpret that there is scale buildup. I can provide comparison photos to illustrate if desired. 
Dave Hupe
1994 C320 (#32) "Mayan Sun"
Holland, MI