Ray, I had a simular diesel leak with my Webasto. Your right with regards to finding out where it is leaking. For less than $70.00, I installed a new "fuel pump pressure pipe service kit" (only the long pressure pipe) Part #5000216A and a kit containing a new banjo bolts, gaskets and banjo tubes. Part #66548A. When you take this apart and compare the old vs. new, you'll understand why the old style tends to leak. It worked for me. I did install new fuel lines and hose clamps from the fuel filter to the unit (supply) and from the 3/8" to 1/4" connection for the return side. Mine still puts out white smoke on its initial start-up, but clears up at temperature. I also installed a marine bilge blower in this bay. Mine leaks alittle smoke @ the housing and smelled up the coach. This cleared up the smell. Call Eggimann Motors & Equipment @ (608) 271-5544. They are in Madison, WI.