Bleeding a 3 Cylinder Diesel

[SawWhet]

We have a 1997 Beneteau 321 (new to us this season)
Equiped with a Yanmar 3GM30F--Older style Racor primary filter and standard Yanmar filter
I would like any suggestions on bleeding the fuel system when replacing the filters

[St Anna]

I have a similar age yanmar running the kohler genset. I will find the manual for you.
Saying this, however;

I undo the 'nut' at the yanmar filter end and have to crank the engine until fuel spirts out. Tighten the '2nd filter nut' and all will be well.

I am planning to run a car fuel pump with electric switch - one for the main and another for the genset. This is great for bleeding and also if you are at the dregs of your tank in a rolly sea, it will assist in the fuel delivery. I used this on the last yacht [St Anna] very successfully.

[aa3jy]

There are (2) bleed points on the low pressure side of the 3GM30F. Also use the lever on the manual pump located up stream from the primary fuel filter. On top of the primary fuel filter open slightly the smaller(?12mm?) of the bleed bolts at the same time press down on the manual fuel pump until fuel bleeds out as well as any air bubbles..keep pumping until only fuel spurts out with no air bubbles. Close off the bleed bolt at the same time pushing the manual lever down..making sure no air is sucked back in.

The second bleed point (?12mm bolt?)is at the entrance to the high pressure pump..just underneath the 2" rubber hose leading to the heat exchanger. Use the same technique as described above.

Also if necessary one can crack open one of the high pressure lines on the side of the injector..this will require the engine to be turned over by electric starter..and watch for spurting fuel.

[mm2187]

When replacing the filters you want to either have some spare diesel on hand or keep what you take out to refill the filters before you attatch (to minimize the priming you will have to do). Then loosen the nut on top of the fuel filter on the engine. Usually the smaller of the two. Then use the hand engine priming lever (trace if back from your filter inlet) to pump fuel into the filters until all the air comes until you get diesel coming out the top then tighten the nut back up but not enough to ruin the gasket that is there. To make sure you did it correct I would run the engine for a little while just to make sure you got all the air out. You dont want to stall and the most unoppertune time.
Good Luck

[ereiss]

10 mm in both cases, at least on mine. And that bleed on the secondary, a fiendish devil put it there. You have to reach over another screw/bolt to get at it. Have spent more hours than I care to think about trying to get it tight enough.