Chasing Down an Elusive Oil Leak

It’s been a long time coming. We’ve been fighting this mother of all wars for five long, hard years. But yesterday we tasted the sweetest of all fruits-Victory!

Yes, friends, after running our Yanmar diesel hard (2800 rpm continuously) for an hour, not a trace of oil was to be found. Danny, our miracle-working mechanic from Billings had indeed found the elusive oil leak which has plagued us since launching BEOWULF in New Zealand. And now our engine sump will stay CLEAN!

This is the fourth time a “professional” has fought this battle, not to mention numerous amateur attempts on the part of your writer. It took our savior less than an hour to find and fix the problem.

Danny’s technique is worth relaying, because it has the potential to help others with similar woes.

Step one: After general clean-up use a “Brake and Parts” cleaner to thoroughly clean the general area in which you think the leak is occurring (take care as this material is highly volatile-keep the interior well ventilated).

Step two: Using good light and mirrors carefully search for the location of the leak. Ours was found just to the edge of an alternator bracket, where a casing had been machined slightly to allow the bracket to fit, and then been punctured by a wrench.

Step three: Pull a vacuum on the engine using a vacuum cleaner with the hose going to the oil fill or breather vent (we used our central vacuum hose to the oil fill in the top of the rocker arm cover).

Step four: With the engine under vacuum, spray the area of the leak with the brake and parts cleaner.

Step five: Apply “Three Bond RTV Silicone Adhesive/Sealant” to the leak. This material is available in most auto parts stores. The material Danny used is labeled “Cummins Service Products”. The vacuum will suck this into the crack.

Apparently this “Three Bond” material is often used to replace gaskets and is an extremely versatile product to have on board. When storing the unused portion, squeeze out about 1/8″ (3mm) of material from the end of the tube, and then put on the cap. If the tube end hardens prematurely, you can extract material from the body. We’ve now got a couple of tubes of this on BEOWULF (which we will hopefully never use).

Meanwhile, BEOWULF is following the birds towards warmer water and air (it was 56F this morning on board). We’re looking forward to warm air, warm water, and being able to sail without constant attention to lobster pots.

Posted by Steve Dashew  (September 7, 2001)

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