Changing the fuel prefilter on a 21ec

[paulspbe]

Any trick to getting the fuel pump to pick up fuel out of the tank ....All lines are clear but I can't get any fuel passed the prefilter..engine will run until engine filter is low and then die...

 

[rt11002003]

I'm assuming you're talking about the first fuel filter past the fuel tank; the one mounted on the bulkhead forward of the fuel tank. It's normally referred to as "the primary fuel filter"; the filter housing unscrews from the filter head, that's where the fuel lines enter and exit. The filter head is bolted to the bulkhead. When new, that housing can be really tight and a bear to loosen. My housing has a drain plug which can be removed to drain the fuel before removing the housing.

My first R21EC was a 2009 model; one of the first to come with a primary fuel filter. At about 25 hours of engine operation, the engine would stop. I'd drain the housing; it'd start, run awhile and then stop. Then, I changed the filter which was somewhat dirty. That cured the problem.

Later, I changed the secondary filter, the one on the engine. It was perfectly clean as one would expect if the primary filter was doing its job properly.

 

[sheral]

Well we’ll wait for someone who knows a lot more than I do, but I would guess that you have air in the line, which you will need to purge. The engine manual shows you how to do this. I actually installed a purge bulb after the tank and before the primary filter. I haven’t had any issues with air in the lines after changing out the primary filter since putting in the purge bulb. FWIW.

 

[SGIDAVE]

Any trick to getting the fuel pump to pick up fuel out of the tank ....All lines are clear but I can't get any fuel passed the prefilter..engine will run until engine filter is low and then die...

Hello Paul,

On the Yanmar 3YM engine there is a 'priming' lever near the fuel filter on the engine. There is also a "bleed" screw on top of this filter assembly. The procedure is to loosen the bleed screw a couple turns (DO NOT REMOVE IT) then pump the priming lever until fuel starts to bubble out around the bleed screw. Tighten it back up - all set. Note that the bleed screw is plastic and can easily be stripped so be gentle with it.

Not sure of the Volvo set up; suspect it has a similar system for purging the fuel system.

If you're having this trouble after working on the fuel system, you must also ensure the both the primary (back near fuel tank) and secondary (engine mounted) filter assemblies are tight such that no air is being entrained into the system. When you say the engine runs until the filter bowl empties - then dies, well, you must suspect air entrainment. The most likely places for that to occur are the points in the fuel system you most recently 'opened.' Which is the fuel filter, right?

Let us know how it works out,

/dave