Priming fuel system after fuel filter changes

[BB marine]

Last week I changed both the bulkhead mounted Racor filter and the engine mounted Volvo filter. The bulkhead filter was no problem .I did install a Racor drain valve instead of drain plug, bottom of the bowl so I can check for water easier then removing the drain plug. (less mess) . The engine mounted filter , not so easy. I had to remove the filter housing and put it in a vise to remove the filter . In doing this the fuel lines, and two filters are completely dry. Manual says do not fill filters before installing them. Use the pump primer button to prime system. Push and hold for 5 seconds. I want to check for leaks at fuel lines and fuel filters now. My boat is still in storage. I can not run the engine. Will I do damage to the pump running it for a period of time to fill the system with fuel and check for leaks . I don't think 5 seconds is going to fill two filters and the fuel lines. I don't want to deal with a fuel leak if I have one. At the launch ramp. Any information on this subject will be appreciated.
Brian Brown
26 Cutwater
PORT-A-GEE

 

[Andrew Custis]

Hello Brian,

I do not believe this is an issue but I would see what the Volvo mechanics do. I always thought filling the filters back up with diesel when putting them on would make it much easier to purge all of the air out of the system. I would put a call into your local dealers and ask them how they service the engines just to get a second opinion.

Thank you,

 

[Scuffy]

I went to the seminar at Roche Harbor on Volvo D-3's. It seems they are worried about you dumping fuel into the filter bowl and that it won't all go through the filter and you could foul an injector. My Volvo guy fills up the filter housing before reinstalling the filters. The spin on fuel filter on our boat closest to the engine was the one I did not get all the way tight and it leaked air. No start situation. A quick trip to a good Volvo guy and he got a turn and a half on the above mentioned filter held the primer button down for a good bit and it started right up. So I would make sure to use a clean container to fill up the fuel filter canisters in spite of Volvo's recommendation. Even with that I would hit the primer for a while before trying to start the engine.

 

[JeffE]

Prefilling the secondary fuel filter (the one on the engine) is a *really* bad idea. It used to be SOP "in the old days" on engines w/ mechanical fuel injection. But the new electronic injection engines are *much* more sensitive to fuel contamination. All the manufacturers I'm aware of require that you not prefill the filter through its center (outlet). Some (John Deere, for instance), provide a screw-on funnel that ensures you fill the filter from the inlet side.

If you prefill and bypass the filter and screw up the injection pump or injectors, it'll be a huge bill.

That said, on my D4, the priming is done by a pump (looks like a rubber button on the top of the filter housing). It's the best priming pump I've ever used -- it's really quick (meaning, not too many strokes). On mine, it's totally manual (not electric), so you just keep pumping until fuel comes out the side vent w/o bubbles. Pretty quick and easy. It's very well documented in the owners manual.

Jeff

 

[BB marine]

The primer on the D3 is a button switch that activates the electric fuel pump . I used it to Prime the system last summer when I checked the Racor filter for water . I pushed it for the described 5 seconds and started the engine with no issues. I agree filling the filters could contaminate the fuel system and mess up an injector. I just wanted to know if I would damage the electric fuel pump if I ran it for an extended time . The manual states 5 seconds. Thank you all for the feed back .Much appreciated.
Brian Brown
26 Cutwater
PORT-A-GEE