PRIMARY FUEL FILTER INTERVAL?

Sep 25, 2008
464
Catalina 30 MKIII Varuna Boat Club
Hi all,
I have a 1997 Cat30 with a Universal M25XPA 3 cyl. diesel. I periodically check my primary Racor filter for water and over the past 4 years have found not a drop. My engine runs great with regular oil changes and I use only pre-filtered fuel (2 micron funnel), always keeping the tank at least 3/4 full, along with recommended additive and change my secondary fuel filter annually.
The question is, how often should I be changing the primary filter, if no water or clogs?

Thanks and Happy Sailing,
Ralph
 
Jan 11, 2014
12,499
Sabre 362 113 Fair Haven, NY
If the fuel is clean and there is no water or sediment in the bowl, there is no need to change the filter. If you have a Racor 500 filter, it is easy to remove the filter and inspect it. If you see crud on it, it is doing its job. If you see lots of crud on it, then change it.

While you have been diligent in keeping your fuel clean, prior owners may not have been and there may be crud in the tank.
 
Sep 25, 2008
464
Catalina 30 MKIII Varuna Boat Club
If the fuel is clean and there is no water or sediment in the bowl, there is no need to change the filter. If you have a Racor 500 filter, it is easy to remove the filter and inspect it. If you see crud on it, it is doing its job. If you see lots of crud on it, then change it.

While you have been diligent in keeping your fuel clean, prior owners may not have been and there may be crud in the tank.
Thank you for your reply. When I bought this beauty in 2017, I had the tank drained and cleaned and replaced all filters. So, I guess this is part of the reason my primary has no water or traces of sediment. At the end of this season, when I service the engine at winterizing, I think I will change the fuel filters.....just to satisfy myself. Thanks again.
 
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jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,499
CAL 35 Cruiser #21 moored EVERETT WA
:plus: For Dlochner’s reply.
 
Jan 4, 2006
7,090
Hunter 310 West Vancouver, B.C.
With your attention to fuel quality, I certainly wouldn't let the primary go a minute longer than, say, 1000 hours, maybe 1200 hrs. or if at all. Yeah, you could probably go on forever without a change. I have a vacuum gauge on my filter to see how thing are going inside. You'll hear lots of crap about filters disintegrating, losing mystical water absorbing powers, and the usual baloney. I've never seen a trace of change on the primary in many hours of service. I do keep a bit closer eye on the secondary filter and change every maybe five years (500 hrs) more for psychological reasons rather than anything else. They have always looked immaculate.

1684513784571.jpeg


PS - I should have mentioned, if you have a drain plug on the bottom of your filer bowl, you may want to check that out some day. Just drain a few drops to see if you get fuel or water. Personally, not a drop to date. I might also add that I send a hard suction tube into the low part of the fuel tank every few years to see what's going on in there. A Pela oil pumpout pump sucks on the hard tube to get a fuel sample for a look see.
 
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Jul 5, 2011
734
Oday 28 Madison, CT
It is likely you have a lift pump such as a Facet. Some folks forget that there is a fine mesh plastic screen that needs to come out and be cleaned at least once a season, removing, wiping off the magnet, etc.
 
Jan 4, 2006
7,090
Hunter 310 West Vancouver, B.C.
It is likely you have a lift pump such as a Facet.
The Facet Cube pump is in the lower right corner :

1684515731762.png


The fuel is first filtered by the Racor fuel pump before it goes to the Facet pump. The pump inlet filter is 74 micron while the Racor element is 10 micron.

there is a fine mesh plastic screen that needs to come out and be cleaned at least once a season, removing, wiping off the magnet, etc.
Which magnet are you referring to ? The pump body is a sealed construction which does not have access to the interior of the pump.

1684516569766.png


1684516719085.png
 

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Mar 6, 2008
1,267
Catalina 1999 C36 MKII #1787 Coyote Point Marina, CA.
Rpell1, keeping fuel tank full will keep air out. The humid air contains water which condensate at night when cold and water drops down at the bottom of fuel tank. To prevent this, keep tank full when at the slip.
 
May 17, 2004
5,491
Beneteau Oceanis 37 Havre de Grace
As a data point, here is my filter when I changed it a couple weeks a (new on the left, old on the right) -
1684524300780.jpeg


The boat is a 2014 and the filter was last changed in 2015. I drain a little off the bottom of the bowl a couple times per year and have never seen any water in that, and I’ve never had any power loss. The way the filter is discolored at the bottom I suspect trace amounts of water sat in the bottom of the bowl and wicked onto the filter, providing a place for bacteria to grow in the housing itself.
 
Jan 4, 2006
7,090
Hunter 310 West Vancouver, B.C.
The way the filter is discolored at the bottom I suspect trace amounts of water sat in the bottom of the bowl and wicked onto the filter, providing a place for bacteria to grow in the housing itself.
Somewhat unusual to see bacteria growing up the filter like that but can't think of any other way it got like that. I think I've only changed primary elements two or three times in 24 years. The element always looked new. Maybe I'm just lucky. Maybe clean fuel. Maybe the biocide and checking the tank for water every few years. Or maybe all of the preceding but it seems to work.
 
Jul 5, 2011
734
Oday 28 Madison, CT
Not the Facet pump I was referring to which is cylindrical and has a removable bottom to allow access to the screen and magnet. Sorry I took you in a wrong direction.
 

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Jan 4, 2006
7,090
Hunter 310 West Vancouver, B.C.
Not the Facet pump I was referring to which is cylindrical and has a removable bottom to allow access to the screen and magnet.
1684529634739.png


Holy snapping caramba ! Never seen one like that before. I think that one is made from 24KT gold. I like that it's maintainable but not to the tune of that price. Mine was about $35.00 CAN a few years ago. Not a problem if mine craps out is it will pass fuel in the failed position but adds no pressure. I'm not able to see a drop in speed when the power is removed from the pump when running flat out. The fuel tank is higher than the engine injector pump so I often wonder why I installed it when it does little or nothing. Maybe if a filter starts to plug, it'll pay for its keep.

I take it the magnet is part of the pumping mechanism ?
 
Jan 7, 2011
5,355
Oday 322 East Chicago, IN
As a data point, here is my filter when I changed it a couple weeks a (new on the left, old on the right) -
View attachment 215853

The boat is a 2014 and the filter was last changed in 2015. I drain a little off the bottom of the bowl a couple times per year and have never seen any water in that, and I’ve never had any power loss. The way the filter is discolored at the bottom I suspect trace amounts of water sat in the bottom of the bowl and wicked onto the filter, providing a place for bacteria to grow in the housing itself.
@Davidasailor26,

What filter do you have? I found a spare filter element that looks just like, but I don’t think it fits in my old Groco fuel filter housing.

Curious why the PO had it on the boat,


Greg
 
Jan 7, 2011
5,355
Oday 322 East Chicago, IN
My old Groco filter doesn’t have any drain or water separator. I replaced the filter around 2015 (I bought the boat in 2014). Old Filter looked new.

I pulled it again recently and it was a little brown, but not dark. I put it back in and made sure I have a new spare on hand in case it needs to be replaced.

My tank doesn’t have an inspection port…need to add one sometime just so I can see what is in the tank. For now, will pull the filter out annually and see how it looks.

Greg
 
Jan 4, 2006
7,090
Hunter 310 West Vancouver, B.C.
My tank doesn’t have an inspection port…need to add one sometime just so I can see what is in the tank.
Greg, this is my idea of an inspection port ........ cheap and easy. This is where I insert the long stiff tube and the Pela oil extractor pulls up a sample to see what's in the fuel besides fuel. Actually, I have now inserted a short length of clear 1/2" vinyl tubing so I can see if any crud is coming up as the pump is pulling. The tank is tapered towards the keel so I have a low spot in the tank where all the garbage will accumulate, if there is any.

1684559097516.png


Just can't live with the idea of using a sizeable inspection port and run the risk of leaking fuel around and down under the tank.
 

NYSail

.
Jan 6, 2006
3,132
Beneteau 423 Mt. Sinai, NY
With my racor 500 I inspect the bowl throughout the season and typically change the filter every 3 years regardless of condition. I use a 30 micron on the primary……. Never have had any water and filter is relatively clean. When I bought the boat in 2017 I vacuumed the tank bottom using an electric fuel pump. I have no inspection port and just used the tank sender access. My tank which is plastic has a sump under the pick-up tube that was loaded with guck……..

Greg
 
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