After a year of a mysterious antifreeze leak on our M35B engine- a chance reading on a C34 forum pointed me in the direction of the heat exchanger/manifold hose at the back of the engine. Regardless how much I tightened the hose clamp on the manifold resevoir outlet, antifreeze managed to leak slowly. It was very difficult to see.The manifold resevoir outlet neck had a raised "nub" left over from when it was cast. This raised area allowed the small leak to form. I sanded the bur off the casting. Unfortunately, I had to destroy the hose to remove it. This hose is an odd size; 1 1/8" ID and is wire reinforced. Jamestown Supply in Rhode Island was able to supply a replacement hose.