How efficient are fuel filters?

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perko

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Hi all,
Everyone here has been amazing with helping me in my times of need. Now I need to ask an embarrassing question. How efficient are fuel filters?

My car sputtered and died the other day and I thought it was gas, so i went for a small hike and returned with a tank. Thing started up fine. Then today the same thing happened but it kept sputtering and dying. I pulled off the fuel filter and blew it out onto a white sheet of paper; after the fuel evaporated I was left with a small desert of rust...

So my question is how good are fuel filters? There is clearly a lot of rusty gas that I have been running through the engine. Should i be worried that I have done serious damage? Clearly the tank, sender, and lines at least up to the filter need to be replaced or cleaned, but if there's a good chance there's more serious problems then I need to assess my options. I know i'm a dumass and that this has clearly been an existing problem.

318 duster.
 
You are not a DA, this is just a learning experience. the tank definitely needs to be pulled and cleaned out & possibly a new tank (visual after cleaning it & go from there). the canadian "Spectra" brand is VG (I've used several & good reviews from others)
 
2x on pulling the tank, replacing it or get it cleaned and resealed. some radiator shops can clean them out and reseal them and repair them if needed. Might be cheaper getting a new one and also replace the lines if there pretty bad.
Ran into a problem like that with my 59 Rambler. Tank must of been rusty inside, kept on plugging up the filter if I drove it for awhile and the car would stall on me, so disconnected the filter, blew it out, reconnected it and ran fine! I Wised up and pulled the tank and had it cleaned up. No problems since!
 
My old 62 FJ-40 Landcruiser had really really fine rust inside, more like talcum powder or something. (It ended up with a 360, 340, and 318, in it's life) I bet I had the tank off it at least 3 times, rolled river pebbles, scoured it with course sand, pressure washed, everything I could think of. For quite awhile, I ran it with two filters, one an AC filter / sediment bowl at the carb, and I STILL occasionally got an idle jet plugged, and had to pull the top of the carb off and clean it out.
 
Not a dumb question at all and I don't take you as a D/A at all. We all have to learn sometime. Fuel filters are rated in microns. The lower the micron # the smaller piece of debris they'll catch. A 10 micron filter is a super fine filter but the only issue is it's harder to draw fuel through them so they don't work good on the pump inlet side and they'll clog quicker. I generally run a 100 micron filter before the fuel pump and a finer one after. If your tank, lines, and pickup are all in good shape there's not really a need for anything finer than a 30 micron after the pump. In your case you have surmised the situation correctly that you need to do something about the tank/lines/pickup. Once you do that and get a good set of filters in place you'll be set for a long time. BTW: look on Summit or JEGS (or your favorite performance parts supplier) and search through the fuel filters and you'll see a lot of them are cleanable. Their more expensive but will last nearly forever. I never buy something that doesn't have a micron rating so I know what I'm buying. I run a really large 8" 100 micron on the inlet side since it's located back by the tank and not as accessible. It was expensive but I have a 408 that requires quite a bit of fuel and it's large size means it can flow all that's needed for a very long time between cleanings. In fact after I ran it 2 yrs. I pulled it apart to check it and it wasn't even 2% filled. My tank, lines and pickup are new which helps that a lot
 
OK, so it sounds like i can be relatively confident that I haven't damaged the engine bad enough to be too concerned? first things first i guess, how do i dispose of a bunch of shitty gas? I live in a suburban-ly dense ocean-side community... in California. I'll bet there's more than half a tank in there. maybe 10 gallons? sketchy...

Are there any suggestions for the tank to pump rebuild as far as parts and manufactures and or potential upgrades? I say screw it i'll buy new parts. Do it once do it right. I am on a budget though.
 
If you pull the tank, keep the lock ring for the sending unit, the new ones are not made properly and will leak. Save your old lock ring...

There are a few OEM ones floating around for sale if you can find one...

You may be able to drop your tank and flush it with water to get all of the sediment out, then put it back up...
 
krazykuda said:
If you pull the tank, keep the lock ring for the sending unit, the new ones are not made properly and will leak. Save your old lock ring...

There are a few OEM ones floating around for sale if you can find one...

You may be able to drop your tank and flush it with water to get all of the sediment out, then put it back up...
Click to expand...

X2...note his comment on the sending unit lock ring, that IS important. I would pull the tank and clean it, see how rusty is might be. you will no doubt need a new sending unit I bet at least. blow out the long line between the tank and pump, I had a bug show up in one once, that sometimes plugged the line at the worse times!

most of us no doubt, just use a quality filter up a the engine I bet. just realize if tank is providing rust, just a tiny piece that gets into the carb can cause drivability problems.
 
As for the fuel, you might be able to strain the fuel through some fine cloth a few times and re-use it if it is fresh. But it certainly would be best to dispose of it. Evaporation from a large container does not seem to be an option for your situation. Maybe call your local county landfill if they have that in your neck of the woods.

BTW, you can get the Spectra tanks (from Canada) from a number of sources. And there are far-eastern made ones that cost less.
 
On the pickup, inside the tank there is a sock, a fuel filter. When you are driving the rust gets pulled around this sock and it stops up. After it sputters and dies, the suction that is holding the rust to the sock also stops so the rust particles float or drop away and then it will start and run. Till it sucks the rust back up and starves again.This is the first filter, then there should be one before the carb.
 
I can tell this is going to be a huge pain in the ***. Does anyone know of any good write ups on dropping the tank?

My biggest concern is what to do with the old gas. I can't burn it off people would notice, and there's a shitload of it. I don't even know how i'd store it or transport it to the haz dump.
 
When I drained the tank in my Barracuda, I gave it to my neighbor for his lawnmower. I siphoned it right into his gas can.
 
Siphon it into a 5 gal gas can, or buy a cheap 12v electric pump, put a inline filter in it and then pump it into a 5 gal gas can. After you get everything changed, install a new filter and pump it back into the car. It will have been filtered twice, plus add new gas and install a new filter up by the carb.
 
put it in a can let it sit for a week so the dirt and rust sink then carefully siphon it in another can all but the last inch or two then use it . its been done a million times maybe more .
 
-How old is that filter? If it's like 2 or 3 or 5 years old, I would just replace it, blow the line out to the tank, and drive it.I would pull the filter off in a couple of hundred miles and check it. And keep a new spare in the GB. That's what I would do.
-But if the filter is only weeks old, well then, I would just replace it,blow the line out to the tank, and drive it.I would.....etc
-I have had experiences, where after a few filter changes, the sediments stopped coming, and I never had to remove the tank. Filter's used to be 99 cents, so that was like $2.97 total cost and I changed them on the side of the hiway on occasion;no big deal.
-Now I'm not saying that you should do what I do, cuz obviously, cleaning the tank out in your garage will likely, prevent you from having to swap out a filter at -20*F. I'm just saying what worked for my lazy azz.
-I have taken carbs off, that had the bottom of the bowls full of sediments to nearly the jet opening, and the engines ran fine.
But then I do a lot of stuff that others cringe at.
-My thinking has always been, if it makes it through the low-speed circuit, it is too small to make trouble, and if it makes through the power circuit, it will be consumed in the process. It's just iron oxide, and it burns at atmospheric pressure.It probably came out of the line and not out of the tank. I would check the lowest point of the fuel line. It's probably soft, and getting ready to pop.
-I hate taking gas tanks off. I have visions of going up in flames!
 
Yeah, I put a new filter on and it clogged up in about a minute. I'll bet the lines are clogged up. Probably the pickup sleeve too. What's the consensus on trying to blow out the line and filter and letting it idle to burn off some fuel?

After doing some research it seems like I have 5/16 line, it seems like it would be the same hassle to switch to 3/8 if I got a new fuel pump. Is that something that I should consider?
 
When I used to work on a pit crew for a Baja 1000 race truck, we were often stuck using Mexi-Pep in our chase vehicles. This was stored in 55 gallon barrels sitting in sun then cold nights so full of condensation and rust/sand. This was a constant problem until I was talking to an old pilot who flew small planes between Mexico and US in 60's, probably not hauling tortillas back to US, but he told me that they always used to put a chamois in a large funnel. It would catch any moisture or particles in the chamois.
now for you kids that were born after mid 70's, a chamois was what you dried your car with after washing. Think thin piece of leather size of small towel. Dont know if they still even sell them thanks to micro fiber towels but if you can find one, filter fuel out then put back in after clean out or run in mower. I would not worry a bit after filtering it to put back in car and run it.
 
perko said:
Yeah, I put a new filter on and it clogged up in about a minute. I'll bet the lines are clogged up. Probably the pickup sleeve too. What's the consensus on trying to blow out the line and filter and letting it idle to burn off some fuel?

After doing some research it seems like I have 5/16 line, it seems like it would be the same hassle to switch to 3/8 if I got a new fuel pump. Is that something that I should consider?
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If I am right that the rust originates in the line, then blowing air backwards in the line will just push the sediments towards the back, possibly into the sock, where they will fall to below the fuel pick-up point. But they are still in the vicinity of the pick-up and inside the sock, and ready to migrate down the line again at any time. And using air, it is just not possible to blow that junk all out. If you were to remove the line from the jumper at the back, and from the pump at the front, then you could blow the line out, but air alone will not clear the line. It would need to be liquid/air flushed.This is why I bought a handful of filters.My problem went away after the third filter, but I also cut out that soft spot, and jumpered it. It was a low spot just under the rear seat.
But if I am wrong, and the rust originates in the tank, well then you will be changing a lot of filters,until you drop and clean or replace the tank.

Installing a 3/8 line is fairly large undertaking and only necessary for after about 400 hp.
 
perko said:
The local hazardous waste dump accepts it but i'm at a loss for a safe way to transport it 20 minutes away.
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I'm not sure what it's like in CA but here there are a number of places that will accept old gas as long as it's in an approved gas container.Just pick up a couple cheap used ones from CL to hold the gas.

When you have the car jacked up,a good plan is to use one of those boat gas hand pumps with a bit of hose into the tank to suck the gas out and down into the container.That way keeps spillage to a minimum plus the tank is much lighter and easier to remove afterwards.

Quick and dirty way is to drop the tank with the filler hose still attached (keeping that end high as it comes out) then once it's out,tip the tank so the gas comes out the filler hose into a large funnel into the gas container.
 
Hey, so i'm going to order some parts tomorrow, but I'd like to run my theory by everyone so see that they think.

I went back out today to get the thing off the side of the road. I pulled the new fuel filter/blew it out and it looked mostly clean. At least clean enough to not cause a serious problem. I was able to start it and drive it about 1/2 mile before it died again. Then i rope towed it to a safe spot.

I think that the main clog is in a line or at the pickup. It makes sense that there is crap in the tank because this thing sat for a few years. I knew i should have dropped the tank in the beginning, but i was in denial. I did pump some gas out of the tank and it had a little grit in it but none of the fine rust dust that came out of the filter.

My theory is that that after it sits awhile the sediment settles enough to let the motor run for a bit before it plugs up again. Since the new filter looks mostly clean my money is on the problem being further back. Does that sound like good reasoning?

Here's my parts list. Please let me know if yall think i've forgotten something. Please feel free to make suggestions as far as brands or anything else.

Keeping the 5/16 - trying to limit the "while i'm in there" syndrome.
Gas tank
fuel sender
fuel lines
fuel filter

Thanks again everyone!
 
When it quits;
Is the carb dry? and does it require a great deal of cranking to get it going again? Did anyone ask about a plugged tank vent? Cuz it could do the same thing....as could a severely restricted fuel line, like a kinked or defective jumper or an almost rusted up steel line.The pump could even be sucking air somewhere.
I dunno about you, but I don't have several hundred dollars laying around to just throw parts at a car. You may in fact need all those parts, but I'd be doing some more detective work first.
 
Fuel tank removal is pretty easy in these.....
- Siphon out what you can.
- A strap under the tanks holds it in place and is usually held by 1 nut on a j-shaped bolt hooked into the chassis. Put a jack and board under it for support. Remove the fuel line, the wire for the fuel sender, and disconnect any ground wires in that area. Disconnect any vent lines. Loosen the nut on the j bolt and start lowering the tank a bit at a time as you continue to loosen the nut.
- The filler neck usually enters the tanks via a large grommet in the tank and just slips into the grommet and tank, so dropping the tank just involves letting the tank slip off of the filler tube at the grommet; you may have to wiggle it around to get it off; some silicon spray around the rubber grommet helps.

There are plenty of good filter suggesting above; and yes, you can still get real chamois.
 
Make sure not to kink the rubber hose between the sending unit and the main fuel line. I've seen them kink and restrict fuel flow... Keep it good and straight...
 
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