Timing of Fuel Filter Replacement

[Toots]

I need to replace the fuel filters on my Yanmar 260. The main tank is about 1/2 full. Wondering if it's best to fill up the tank prior to, or after, changing the filters - or if it doesn't matter either way. Bearing in mind that we've had a fairly rainy winter here in the PNW. Thoughts?

 

[knotflying]

Does not matter. I would always shut the valve off at the tank though.

 

[dbsea]

I have to change the pre-filter and on-engine filter in my D6 Volvo as well, this month. I already have the filters, but all the videos I've watched show the instructor having a small bottle of diesel fuel to fill the pre-filter with. I don't exactly have a soda bottle of marine diesel lying around my townhouse. It's probably an easy thing to get but also one of those easy things that feels difficult! Agree with knotflying on the shut-off valve. 🙂

 

[Gunner065]

I have to change the pre-filter and on-engine filter in my D6 Volvo as well, this month. I already have the filters, but all the videos I've watched show the instructor having a small bottle of diesel fuel to fill the pre-filter with. I don't exactly have a soda bottle of marine diesel lying around my townhouse. It's probably an easy thing to get but also one of those easy things that feels difficult! Agree with knotflying on the shut-off valve. 🙂

When I replaced these filters on my Yanmar for the first time, I purchased a small diesel container and half-filled it. Diesel, if not exposed to humidity, can last a while.

Then I poured some in a red solo cup and pre-filled the filters so as expedite the air bleeding portion of re-installing. The Yanmar Owner Manual specifies to turn the ignition key (without starting the engine) 5 times for no longer than 10 seconds (as it might harm the starter). This will prime your pumps and hopefully bleed the air out.

It looks more daunting than it really is.

 

[BB marine]

I have to change the pre-filter and on-engine filter in my D6 Volvo as well, this month. I already have the filters, but all the videos I've watched show the instructor having a small bottle of diesel fuel to fill the pre-filter with. I don't exactly have a soda bottle of marine diesel lying around my townhouse. It's probably an easy thing to get but also one of those easy things that feels difficult! Agree with knotflying on the shut-off valve. 🙂

I'm surprised that the video's for changing the fuel filters on a D6 Volvo common rail are showing a step of pre filling the filters. The common rail fuel system can be bled easily without filling the filters. Filling the filters does make bleeding quicker but there is also the chance of spilling fuel and fuel contamination. The common rail injectors and injector pumps are sensitive to any contaminates. This is the reason for the fine filtering (2 micron). When the filters are pre-filled you are by passing the filtering. Yes a clean container that is thoroughly wiped and clean would be ok and chances are would not cause harm. But why take the chance when the system is made to prime and and go. There is no chance of contaminate. 2 micron filter will not let a particle larger than .000079 pass. You can not see a 2 micron particle with out the aid of a microscope. The lint from your rag is larger than 10 microns because you can see it.

The old school mechanical diesels also need clean fuel. The practice of filling the filters with fuel was a common practice. The injectors and pumps are sensitive to dirt but not as sensitive as the common rail. The old school had a different fuel system that was not nearly as easy to bleed as the common rail is. Many folks with common rail use the same method as old and have never had an issue. When I serviced my Volvo I aways did dry filter installs and used the engine fuel system
primer. After priming the system I would crank the engine over for about 3 or 4 seconds. If the engine did not start I would prime one more time for about 10 seconds. The engine never failed to start the second time. I would guess more than 50% of the time it started on the first time.

"As per Volvo’s recommendation ,NOTE! Do not fill the new filter with fuel before assembly. Contaminations may get into the system and cause damage and malfunction."

I use the same method when changing the fuel filters on my Mainship powered by Yanmars. Dry install and prime.

 

[dbsea]

Thanks Brian! Bleeding sounds a lot easier than messing with diesel fuel. 🙂

 

[dbsea]

I was 50/50 successful in changing my fuel filters. The on-engine filter was no problem. The pre-filter has been problematic. I am unable to remove the screw plug from the bottom of the pre-filter unit to drain it. I was using the recommended 14mm ratchet and pulled so hard it rotated the entire unit but can’t unscrew. I suppose I can just replace the filter by removing the T and the top cover. How best to resolve this?

 

[BB marine]

I'm going to assume this is the first time the 1/4" pipe pipe plug at the bottom of the filter has been removed. The first go is a PIA. I used a strap wrench on the filter housing to support it while using a 6 point socket to insure I did not round the plug head. With some persistence the plug loosened. I installed a Racor drain valve after this and I was able to drain the housing for water inspection with ease. The filter housing design is to separate the water and heavy particulates out of the fuel and deposit to the bottom of the bowl. It is a good practice to drain the bowl when ever replacing the filter. I don't know why the drain plug is installed so tight. It is a taper pipe thread. It doesn't need to be that tight to seal! Unfortunately the folks that install it don't know that!!! Good luck!

 

[dbsea]

Thanks Brian. I can't comment on when/if the plug has been removed since the boat is new to me as of October. I do know the filter in the unit was changed last April based on the maintenance records, but unclear on the draining portion. I was using a 14mm ratcheting flex head Dewalt wrench, that's all I've got unfortunately. I have a nice bruise on the inside of my palm from pulling so hard (in both directions). Can you confirm if it's clockwise or anticlockwise to loosen it? I know sometimes these things are reversed because they are considered upside down.

 

[BB marine]

It is a standard pipe thread. Right to tight left to loosen.

 

[dbsea]

It is a standard pipe thread. Right to tight left to loosen.

Thanks, I'll try again when I have some more time. I ordered a replacement venting drain from Racor as you suggested, so in the event that I can actually get it out I'll swap it with that!