Fuel line maintenance

NYSail

.
Jan 6, 2006
3,048
Beneteau 423 Mt. Sinai, NY
hello all,
I change my fuel filters each year and find little debris, however boat is 30 years old and I am sure there is sediment in tank. I have never had a stall due to fouled filters and have motored through some extremely choppy waters for long periods churning up tank. Does anybody "blow back" the fuel line to clean potential blockages in the pick up line. My boiler guy blows back the line in my house every year..... Why not on boat just to make sure?

Thanks
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
if you have a square tank i would not recommend blowing back with any amount of pressure over 3 psi as you could rupture your tank ....as for if it helps or not i would think that if you had a clogged fuel line from the tank it would be better to blow it clean from the tank end and not restock the blockage in to the tank only to have it come back again ...you can also remove the pickup tube and clean it and remove that little screen on the bottom of the tube as the fuel filter will catch the trash that it picks up from the tank
 
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Jun 3, 2004
890
Hunter 34 Toronto, Ontario Canada
I would clean the tank. If you do not have a cleanout opening, cut one and install a cover/port. I cleaned mine about 12 years ago- the boat was 22 years old then- I could not believe how much goop was in it- the last 2 gal I siphoned out looked more like they came out of my eaves troughs than the tank. I cleaned it again a cuple of years ago and it was pretty clean.
 
Oct 22, 2014
20,993
CAL 35 Cruiser #21 moored EVERETT WA
It's not a matter of if but when. My boat is 42 years old and I imagine also sorts of goo is in the bottom of the two 85 gallon tanks. Only issue is how. When bought the boat there was 150 gallons of fuel in the two tanks. No inspection ports. And an old truck primary filter. I've replaced the filter with a Racor 500 after an engine shutdown. Next priority the tanks.

Metal tanks that tore the teeth out of 1" hole bit when installing a heater pickup tube. Wondering how I'm going to cut an inspection port.
 
Feb 14, 2014
7,399
Hunter 430 Waveland, MS
I change my fuel filters each year and find little debris
Install a Vacuum gauge on your Fuel Filter.
No change in Vacuum at say 2000 rpm, why change your filter cartridge at all.

Don't run your tank empty or change your working capacity to to 90% of rated volume.
Any "gunk" is probably stuck to sides, if you have experienced 4 foot seas on partially filled tank and not plugged your filter. So why worry. Keep 2 or 3 new cartridges on board to filter any loose gunk.
BTW there are sonic detectors and/or cleaning devices if you are really worried.
Jim...
 
Feb 14, 2014
7,399
Hunter 430 Waveland, MS
Install a Vacuum gauge on your Fuel Filter.
Here is what I have.
Racor 500 filter.jpg

Green vacuum reading ok, Yellow is needing change. Red is plugged.
FWIW I have never seen a drop of water or change in vacuum and on same cartridge now for 2 years. Cartridge rated at 60 gallons/hour versus my engine ≈0.75 gph at 2000 rpm.
Jim...

PS: The blue masking tape haw nothing to do with the filter. Top of blue tape is my normal static boat water line as a convenient spot to reference inside my boat.
 
Jan 4, 2006
6,444
Hunter 310 West Vancouver, B.C.
Metal tanks that tore the teeth out of 1" hole bit when installing a heater pickup tube. Wondering how I'm going to cut an inspection port.
No need to cut a large hole.

Fuel Tank Pump Out.JPG


This is a 3/8" hole in the top of the fuel tank. No need to cut a full size inspection port unless you're a glutton for punishment. I slip in the tube of a Pela oil extractor to pull a fuel sample out. If nothing shows, any gunk is either stuck to the wall or the fuel's not contaminated. If anything does show, I will let the fuel sit quietly for a few days and then pump out until nothing shows.

As JamesG161 says, a vacuum gauge is the best indicator of any dirt getting to the primary filter.

DSC_0511.jpg


After that, don't go looking for trouble as Benny17441 alludes.
 
Oct 29, 2005
2,355
Hunter Marine 326 303 Singapore
if you have a square tank i would not recommend blowing back with any amount of pressure over 3 psi as you could rupture your tank .......
Woodster, I did use a dinghy pump to blow back a blockage once. This pressurising of tank didn't occur to me. Now I'll be more careful about it should there be a need to blow back. Thank you.
 

NYSail

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Jan 6, 2006
3,048
Beneteau 423 Mt. Sinai, NY
Good sound advise guys. I will pull the feed tube, inspect clean and take a sample off the bottom and see what I'm dealing with. Like I said..... My primary is always clean and when I drain the bowel on my racor 500 it has minimal sediment. I'll report back.....

Thanks!
 
Oct 2, 2008
3,807
Pearson/ 530 Strafford, NH
if you have a square tank i would not recommend blowing back with any amount of pressure over 3 psi as you could rupture your tank ....as for if it helps or not i would think that if you had a clogged fuel line from the tank it would be better to blow it clean from the tank end and not restock the blockage in to the tank only to have it come back again ...you can also remove the pickup tube and clean it and remove that little screen on the bottom of the tube as the fuel filter will catch the trash that it picks up from the tank
I'm thinking that the vent hose should relieve the pressure like it does when I fill the tank. Maybe you could open the deck plate since it fills on the top of the tank that could relieve the pressure. I always get some dirt in the filters but this year they were nearly clean. Must be all the miles we put on during the winter.

All U Get
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
I'm thinking that the vent hose should relieve the pressure like it does when I fill the tank. Maybe you could open the deck plate since it fills on the top of the tank that could relieve the pressure.
as long as you don,t use a air pressure hose off a compressor you will be ok ...a compressor hose can pump air in faster than a vent can relieve .....a hand pump is fine just be carefull with high pressure
 
Jul 7, 2004
8,402
Hunter 30T Cheney, KS
As to cause and effect, I read in several places that water (on a boat no less) is a big issue with diesel fuel. "Diesel fuel is highly hygroscopic, meaning it readily absorbs water from moisture in the air. Water contamination in diesel fuel is of particular concern as it can lead to the corrosion of steel components and the promotion of microbial growth."
I installed an H2Out filter for my tank vent in the spring and the crystals need to be rejuvenated already. They are turning from a dry blue color to pink. H2Out sells new media and/or has instructions on how to dry it out again.
I guess there were some issues with the clear plastic container walls so they changed to metal. I like the clear. I can see when the crystals need to be changed or dried out again.

Here's my setup when it was "new and blue".
 
Last edited:
Feb 14, 2014
7,399
Hunter 430 Waveland, MS
.a compressor hose can pump air in faster than a vent can relieve
This is true for any vented tank!

These tanks are designed for Vacuum service (not collapse)...
1) Fuel Tank (Fuel pumps)
2) Hold Tanks (RV pump out vacuum pumps)
3) Some Water Tanks. (Big supply pumps)
4) Fuel Filter housings

My point is the tank is therefore good to at least the opposite positive pressure. Say ≈10 psi.
Once you cut a hole in a tank... "bye bye" design pressures (probably not too risky..BUT?).

What is NOT designed for with Big Positive pressures, as woodster points out...
1) Gaskets
2) Hoses
3) Hose clamps.
4) Pipe fittings... (maybe)

Maybe you could open the deck plate since it fills on the top of the tank that could relieve the pressure.
Deck fills DO allow additional venting!:thumbup:

This is why I love my Vacuum fuel pressure gauge!
Jim...
 
Feb 14, 2014
7,399
Hunter 430 Waveland, MS
I installed an H2Out filter for my tank vent in the spring and the crystals need to be rejuvenated already. They are turning from a dry blue color to pink.
Dang!:soapbox:
About a year ago, I was discussing (with a buddy) making and marketing one of these "desiccators". The crystals are just Granular DrainO ( anhydrous Sodium Hydroxide with a PH indicator "color" change). You can rejuvenate the crystals (PM me if interested in how).
Jim...
 
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Jul 7, 2004
8,402
Hunter 30T Cheney, KS
Someone is always one step ahead!
H2Out sells the media but they also have instructions on drying the crystals out on a stove. I'm thinking of having a backup supply to swap out while I take the saturated media home to process.
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
Someone is always one step ahead!
H2Out sells the media but they also have instructions on drying the crystals out on a stove. I'm thinking of having a backup supply to swap out while I take the saturated media home to process.
Justin i really don,t think i want to put that stuff (draino crystals) in my oven where i cook my pizza....... it may have dire effects on my toilet habits
 
Jan 4, 2006
6,444
Hunter 310 West Vancouver, B.C.
How does the cleanout port allow you to get around the baffles in the tank?
The port is more for just pulling a sample at the lowest point in the tank looking for contamination.. So far (knock on plastic) I've seen no problems after 17 years since new.