[C320-list] Secondary fuel filter on Yanmar

[Jack Brennan via C320-list]

So I was changing the Racor 500 fuel filter today and thought, what the hell, maybe I'll also change out the secondary fuel filter on my Yanmar 3GM30F.

Boy, is it in a tight spot. Starboard side of the engine, with cables and hoses running around it and the bulkhead right next to it. With my farmer hands, there is not enough room to get a grip on the metal bowl and the piece that screws onto it. Couldn't work a channel lock in there, either.

I passed on changing it for the moment. But I'm wondering, does anyone have a technique that makes this doable? Or does everyone just leave it alone and hope for the best?

Jack Brennan
Sonas, 1998 Catalina 320
Tierra Verde, Fl.

[Timothy Woods via C320-list]

Yup, that one sucks. You take a long handle flat tip screwdriver and tap it
lose using the lugs around the top of the bowl. After you do it a few times
it gets easier.

Tim #375

[SARA SCHROEDER via C320-list]

Jack,
I have had the same problem. ZERO tolerance around that thing. The bottom of the filter literally is right on top of the hull and I could just get the width of a plastic cereal cup between it and the hull.

Then one day, the plastic bleed screw decided to self-destruct and I was left with replacing it. After talking to the smart dudes at the local marine store I learned I could replace it with a smaller version that was effective as the one on there. I replaced the R20S assembly with a 215R10 assembly (10 microns). The flow rate of the new one is 15 GPH which I was assured is more than enough for my Yanmar 3GM30. So far I'm super happy with it and I have space to service it!

Sara
Wandering Star
Seattle
#707/2000

[Troy Dunn via C320-list]

Yup, just tap the nubs gently with a longish flat blade screw driver, works
perfectly.

Always replace the oring when you change the filter. If you haven’t
replaced the nylon bleed screw washer go ahead and replace that too.
Never over tighten the filter housing or the bleed screw. Just get them
hand tight and then gently snug them up just a bit.

Actually I find the RACOR to be the worst job ever. The thing is so low
as to make the little check valve completely useless, and although I always
place a plastic bag under and around the whole thing I always seem to get a
tablespoon of diesel spilled.

Troy Dunn
Hull #514

[Jack Brennan via C320-list]

Ok. One last question. Do I tap the screwdriver from the aft cabin goung forward or from the galley going aft? I'm trying to visualize which way it turns.

Jack Brennan
Sonas, Catalina 310
Tierra Verde, Fl.



Sent via the Samsung Galaxy A32 5G, an AT&T 5G smartphone

[Richard Walker via C320-list]

Many of us added a fuel shut off valve on the line before the filter. Makes a job a lot easier.
Dick Walker

> On Jul 15, 2025, at 19:18, Jack Brennan via C320-list <c320...@lists.catalina320.com> wrote:
>
> Ok. One last question. Do I tap the screwdriver from the aft cabin goung forward or from the galley going aft? I'm trying to visualize which way it turns.

[Jeff Smith via C320-list]

I have a Perkins, so I am not familiar with the exact situation, but it seems to me from a description that a scissors-type wrench similar to those used for oil filters would do the trick. I note that you said channel locks would not work; however, you might try this next time.

In addition to the fuel shut off valve, I highly recommend adding an electric fuel pump. After I change either or both filters, I simply turn on the electric fuel pump and start the motor. The electric fuel pump alleviates the need to bleed the system. It also serves as a back-up to the mechanical lift pump (all relevant for the Perkins, but I assume this would be similar for the Yanmar, with the usual caveats).

Jeff
#121

[Troy Dunn via C320-list]

Great question Jack. I access from the aft berth but with both covers off
to get as much light on the subject as possible.

This video gives you a good idea of how to do this. This guy does really
nice instructional videos, he must be a teacher or professor because his
delivery is amazing and there isn’t to much obvious editing. Very
enjoyable to watch and learn.

https://youtu.be/ub0zfW42mVo?feature=shared


Troy

[Jack Brennan via C320-list]

That's a good video, Troy.

Funny thing. I've owned Yanmar diesels for 16 years and never had to bleed it beyond the screw on the secondary filter. They rumble a little at the start, but then get in the groove after a few seconds.

Jack Brennan
Sonas, 1998 Catalina 320
Tierra Verde, Fl.

________________________________
From: C320-list <c320-lis...@lists.catalina320.com> on behalf of Troy Dunn via C320-list <c320...@lists.catalina320.com>
Sent: Wednesday, July 16, 2025 10:42 AM
To: C320...@catalina320.com <C320...@catalina320.com>
Cc: Troy Dunn <troutw...@gmail.com>

Subject: Re: [C320-list] Secondary fuel filter on Yanmar

[Doug Treff via C320-list]

This assembly has RH threads on it. But you must think about it because it's upside down. When viewed from the bottom, you turn CCW. If viewed from above, it would be CW.

--
Doug Treff
do...@treff.us