No one said education is cheap
but I now know a whole lot more about my Mahe.
The fuel smell was traced to the fuel bleed off manifold to return hose joint. After nine attempts to get it to reseal to the nipple, an email
to a chap at Permatex brought a suggestion to seal it with Indian Head Gasket
Shelac. Coat nipple, coat inside of rubber hose, wait 45 seconds wondering how long to wait and assemble. I let it cure for a couple of hours doing other chores and double clamped. Worked. No need to replace the whole return hose, I did.
But...in the process, I apparently levered and twisted the bleed off manifold and it started to leak at the #2 injector. Not sure where and worried I might crack the fuel line at the nut if it were too corroded, I purchased a replacement line. At the injector, use two wrenches, one on the nut below the fuel line nut and one on the upper nut. But, You can’t just remove the #2 line without a special tool to hold the lower nut on the pump
. So all three are removed. Installed new line (the old was fine) and ran engine still leaks
. In the process, I had inadvertently loosened the nut holding the bleed off manifold. There are three copper or aluminum
that bear under the bleed off manifold banjo fittings that are in turn secured by a 17mm nut. No where is there a torque value for that nut. Note...over torquing the nut will make it leak at the seal ($16+ each). Torque lubed at 15 ft.lb., about the same as the fuel line nuts and a touch more if they don’t seal the first try. Replace all three seals
and if you over tighten the nuts, you get to replace them twice, guess how I know. There are 11 places fuel can leak from between the injection pump
and the engine. Btw, it takes less than 1.5 hours to remove and replace everything down to the bare injectors. It is straight forward but be both clean and methodical.
One more thing. The fuel bleed off return hose is a siphon from the tank. There is no shutoff except for the fuel feed. Both hoses need be closed to do the work
above. I made a hose clamp from 2 pieces of oak 3/4” square and 3” long. Drilled and tapped one for a pair of 1/4 20 x 2.5” bolts and the other so the bolt was free to rotate. Clamp that tight on the return hose and the operation becomes much easier.
While I had the panel out between stbd berth and fuel tank, I replaced all the forced air heater
hose, plus new double wall SS exhaust
on the D4 heater.