Water separating filter

[ftornabe]

Hello,

I want to replace the internal and external water separating filters. Once replaced there will not be any fuel in them. Should I squeeze rubber balloon to push fuel through the line to avoid an air gap? Otherwise I guess I'll pour some fuel into the filters which I want to avoid doing.

Its a 2021 R25.

Thanks!

 

[BB marine]

I will answer this based on it being a D3 Volvo power plant. The D3 does not require filling of the filters. You can install both filters with no fuel. Actually is is best to do it that way to prevent any contamination of fuel to get into the secondary filter. The D3 has an electric fuel pump. There is a push button on the engine that will activate the fuel pump for priming and filling the filter. The manual will state a different procedure but this is what I did. After installing new primary and secondary filters. I pushed the electric primer button for 10 second count. I would stop wait a few moments then repeat the step. Then I would activate the engine start at the helm and listen to the electric pump. When it stopped I would hit the start monetary switch at the helm as the engine cranks it should fire as usual. If it doesn’t I would repeat one more cycle of ten second prime. Then repeat start cycle.

 

[Cutwater28GG]

on the D4. its a manual push on the rubber "button" to prime the fuel through the filters.

after installing new filters and turning the fuel feed on again from the fuel tank.

1. put a small container under the stainless bleed valve. i use a solo cup as it fits pretty well in the space on the cutwater 28.
2. undo a few turns of the bleed valve
3. pump the button until pure fuel and not air comes out
4. tighten up the bleed valve.
5. start the engine as normal.

you dont need to touch the black rubber pump button until you are ready to bleed the air out. also if both filters are empty it will take a number of pumps before the fuel flows.

 

[watson1987]

Also to note about priming the fuel filter, pump the black button on the D4 until all the bubbles stop.

If you don't prime it enough, the engine will start, run for a few seconds, then die, and it will freak you out, but it's just out of fuel. Just prime it again and try again.

 

[Cutwater28GG]

Ive had the same experience!

theres something so reliable about a volvo diesel engine that if it stops on its own - its especially worrying!

 

[Haifisch]

The only part that I see missing in the prior comments after several fuel filter maintenance routines on the D4-300 has to do with once your "think" you've bled the air from the fuel lines:

After you bleed air from the system (I use a clear hose on the petcock) and do a lot of pumping on the black button until there are no more air bubbles in the clear hose: Close the petcock and push the black button some more until you literally cannot pump anymore. (This is from the Volvo manual BTW). The pumping button will become very stiff. Start the engine. It may or may not stop running. Go back and push the button again until it will take no more. Start the engine again, check for leaks and all should be fine. This has worked for me on 4x filter changes.

BTW a PSA on the topic: You should do this bit of maintenance practice on your own at least once rather than leaving it up to your normal mechanics. This is a serious safety issue in the event you are in bad weather or far from home and need to deal with fuel issues far from home or a safe port.

 

[ftornabe]

I forgot to mention, its an outboard. Yamaha F250. There's a primer bulb after the filter then feeds the engine. So I presume after replacing the filter then squeeze the primer to put fuel in the line. Just want to confi
Thanks

 

[BB marine]

Yes pump the primer bulb to help fill filter. The engines lift pump will take care of the rest. Gas engines do not require priming the fuel system.

 

[ftornabe]

ok thanks for the info.