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xxhat · 19-01-2019, 23:33

I just saw this crud in my RACOR 12R fuel filter.

I wonder what I need to do ?

1. Can I just open the drain plug and get the crud out or do I need t remove the filer and replace it ?

2. What is causing this crud ? It looks like some rust. But the tank is aluminium.

Thanks,

jim

**delmarrey** · 19-01-2019, 23:48

It looks like wood chips to me. Have you been doing any wood work on the boat lately?

You will need to pull the bowl and clean it out. Also I'd suggest you have the fuel drained or scrubbed to get the rest of the junk out of there. Your fuel filter should stop it from getting to the motor. But the sooner the better.

Do you have an inspection port on your tank? If so, I'd suggest you take a look inside.

**JPA Cate** · 20-01-2019, 02:27

Fwiw, i've never seen anything that looked like that in our filter bowls. Is it rust? When you drain the bowl, and drain off the fluid, put a magnet by the residue and see if it jumps on. If it does, it is iron based. If you have black iron fuel tanks, it may mean that you have a fair wee bit of water in them, definitely time for a fuel polish....at the very least; possibly time to replace tank.

Ann

ozsailer · 20-01-2019, 02:55

xxhat,
have you refuelled recently. One scenario is that when you filled up the tanks you filled from were awaiting a refill and you got the crap at the bottom of the tank. I have got contaminated fuel in my car so its can happen to boats as well.

Greg H

**44'cruisingcat** · 20-01-2019, 02:58

Does look like rust, but the he OP did say aluminium fuel tanks.

But have you used steel jerrycans or drums to transport fuel?

motion30 · 20-01-2019, 03:03

It does look like rust and it could have came in when you bought. Fuel

stormalong · 20-01-2019, 03:57

Three possibilities: Biological growth, Diesel fuel precipitate, and fuel contamination from a fuel purchase.

My guess biological growth. The bugs grow in the zone between water in the bottom of the tank and the diesel fuel. Water can get in the tank from condensation from the air. As the tank warms in the day and cools at night air is exchanged through the vent. As the tank cools the moisture condenses and sinks to the bottom. This happens a lot in colder climates. Best preventive is to keep the tank full - especially in winter.

When Diesel sits for a very long time sludge can precipitate from it. This is different than bio growth. Quality of fuel can cause this but you as a consumer have no way to tell if your diesel will precipitate sludge.

Contaminated fuel is always a possibility. Your tank may have been clean but that fuel you bought was in a few tanks between the refinery and you. The fuel dock should have a filter in their pump to trap this but maybe not. Best way to avoid this is to buy fuel from someone that sells a lot of fuel.

I'll bet that when you clean the bowl that stuff will be soft and slimy. If so it is biological or sludge. If it is hard and coarse then it got pumped into your tank.

The good news is that your Racor is doing it's job and protecting your engine. Once it is cleaned out keep a close watch on it. Diesel fuel stabilizer may help. Putting a hose down to the lowest point in the tank and pumping out fuel until it runs clear may be a good idea. If it keeps coming back then you need to get your tank cleaned which is another topic. A couple of tanks of fuel may just flush it out.

Dsanduril · 20-01-2019, 04:29

My guess is biological, but it could be any of the other things mentioned above. Willing to bet that if you spin off the fuel filter element you'll find a bunch more on top of the filter element as well (don't ask me how I know). Been in a 'boisterous' sea lately that might have stirred up the tank just before (or while) you ran the engine?

If you spin off the element and it looks clean you an always put it back on, otherwise time for a new filter. Either way, hope the system is easy to bleed. Last thing you want is to find out there's a bunch more of that stuff in your filter and it stops your engine just at that critical moment (it always happens at the critical moment).

**a64pilot** · 20-01-2019, 04:34

Quote:

Originally Posted by 44'cruisingcat

Does look like rust, but the he OP did say aluminium fuel tanks.

But have you used steel jerrycans or drums to transport fuel?

I’m thinking he didn’t, but who he bought it from had steel tanks?

Bio that I have always seen is more of jelly or snot like consistency, not granular.
Take it out and see if a magnet sticks to it, if it does then there is your answer.
Also I believe bleach will usually significantly lighten bio, but have no effect on just dirt etc.

sanibel sailor · 20-01-2019, 04:54

Stuff looks roundish. How about water droplets encrusted with algae to prevent it from coalescing?

Please report back when you drain it.

xxhat · 20-01-2019, 05:02

Thanks.

Will use magnet to check crud.

Only use plastic jerry cans to refill fuel.

Boat has been sitting used for several months.

Need double check steel tank is aluminium. Looks like metal of some sort.

So concensis is to take bowl off and replace filter ?

jim

xxhat · 20-01-2019, 05:06

Do I have to remove bowl and replace filter ?

Would it be possible to just open the drain plug and drain off the crud ?

See if crud comes back ? if it comes back then replace filter ?

Trying to avoid bleeding engine.

jim

CaptTom · 20-01-2019, 05:10

I'm with A64Pilot. Bugs would be slimy.

That doesn't look familiar to me, but I'll throw out out an idea: Corrosion from an aluminum water tank has a kind of sandy, very granular look. If it were soaking in fuel, maybe it would take on that rust color. Again, just a wild guess. The magnet test would still be the first shot.

Dsanduril · 20-01-2019, 05:12

Just my 2 cents - How confident are your that what you see is all the crud? The bowl is really there to trap/collect water. It also collects large particles that spin out before getting to the filter. And that's what you currently see in the bowl. But how confident are you that all the particles are large and will fall into the bowl? IME, where there are large bits there are also small bits building up in the filter....

**delmarrey** · 20-01-2019, 05:25

Try the petcock first. If it comes out, great. If not, then unscrew the bowl. Be sure to refill it with new fuel first before replacing it, unless you have a primer pump to extract the air.
If you get more crud when you run the motor, then I wouldn't run it for very long. You'll need to pump out the tank.