Can you have too many inline fuel filters?

[FORD*DIEHARD]

Just wondering I know sometimes more is not always better , so can you have too many fuel filters? I have one from the main tank to the Electric tank selector valve (photo attached), one from the auxiliary tank to the selector valve and the carb (not sure if it matters but is a Rochester 4v ) has one built in.

I was going to put another one between the fuel pump and the carb.

Are this (03) sufficient or should I add another? If I should add another what filter? I have heard different opinions on clear filters.

Thank you in advance for your time/help,

Sonny

 

[ared77]

My first thought to your original question is "Yes"! (My thinking is that filter after filter would eventually act as a clogged line due to all the screens and the resistance may be too much for the pump)

But back to reality I doubt two or three, or even four?, would be a problem. The one thing I do know is NOT having a filter at all is not a good idea!

 

[Oleguy 74]

more than two is a waste of time and money.one at out put from valve and one near carb

 

[ared77]

You're right about more is not always better, look at the carbs some try to run on stock 289's or 302's...850CFM on a stock small block isn't going to run better..or faster.

 

[Timmy390]

The guys on "Roadkill" put like 5 in a row due to the tank they were using was so rusty. Not sure I would run a DD with more than 2 but if I had a rust issue I would consider it.

Tim

 

[trailerjack]

If something has been sitting for a while, I will usually run 2 fuel filters.

 

[AZ73]

I run a 20 microns before my electric fuel pump (per fuel pump instructions), and 10 after, per sniper instructions

 

[Broncobowsher]

The guys on "Roadkill" put like 5 in a row due to the tank they were using was so rusty. Not sure I would run a DD with more than 2 but if I had a rust issue I would consider it.

Tim

They typically do that so when the 1st gets clogged it is just removed and tossed, then they are left with 4. Keep repeating.

From the factory vehicles of this era had 2 filters. The inlet sock inside the tank and the one at the carb inlet. For dual tanks add one more but there were still only 2 inline.

With old vehicles the sock in the tank often falls apart or just off. Now the prefilter is no longer there. Fuel pumps like a prefilter, keeps the check valves working. Also most aftermarket tanks do not run the prefilter sock, just an open pickup tube.

What I run on old stuff is a cheap filter coming out of the tank, act as the in tank prefilter that is probably not there anymore. Keep big junk out of the lines, selector valve, and pump. Then a good filter to catch the fine stuff just before the carb.

There is a good writeup on the Aeromotive website about filters. Micron ratings and filter size. They show some junk filters and why they are bad.

My go to filter these days, for a cheap final filter, GM EFI filter used on nearly everything from the mid 80s to the late 90s. They are a high flow 2 micron filter. Cheap as you can ask for with that level of flow and filter. Work just fine with carburators as well. Threaded, O-ring sealed connections. The prefilter still used coming out of the tank unless I know there is a functional filter sock inside.

 

[Steve83]

I have one from the main tank to the Electric tank selector valve (photo attached), one from the auxiliary tank to the selector valve...

Those (the tanks) are the 2 sources of trash in the fuel system, so those are enough (until they clog).

...the carb (not sure if it matters but is a Rochester 4v ) has one built in.

That's the failsafe, if all other filters fail to catch the trash.

I was going to put another one between the fuel pump and the carb.

Do you think there's any chance that filterable debris could get into the fuel lines between the other filters and this location? Is the pump going to generate debris? Have you ever heard of a fuel pump creating any?

one at out put from valve and one near carb

Then trash could get to the valve and cause it to leak fuel between the tanks, or let air from an empty tank into the fuel line, causing the pump to vapor-lock.

The guys on "Roadkill" put like 5 in a row due to the tank they were using was so rusty.

Pointless. If it's small enough to get past the first one, none of the others will catch it, either. If the first one gets clogged, none of the others can do anything.

...if I had a rust issue I would consider it.

It would make (slightly) more sense to have them in parallel (tank to 5-way splitter, through the 5 filters, back to a splitter bringing all 5 back to the select valve or pump).

I run a 20 microns before my electric fuel pump (per fuel pump instructions), and 10 after, per sniper instructions

Running a couple of 10s parallel before would accomplish the same effect.

They typically do that so when the 1st gets clogged it is just removed and tossed, then they are left with 4. Keep repeating.

That doesn't make sense - then what would connect those 2 pieces of fuel line where the clogged filter used to be? And how is it even slightly better than simply carrying the 4 spare filters and changing them as they clog? Then there's only 1 thing cut into the line - not 10 connections to leak.

 

[bmc69]

I've been using 10-micron spin-on marine fuel filters on all my trucks for 40 years. No worries....no problems...ever.

 

[Broncobowsher]

That doesn't make sense - then what would connect those 2 pieces of fuel line where the clogged filter used to be? And how is it even slightly better than simply carrying the 4 spare filters and changing them as they clog? Then there's only 1 thing cut into the line - not 10 connections to leak.

Pull the filter and the 3" of hose.
Watch the show, that's what they do.
When dealing with a rusty tank that you should not be trying to use, it does make sense. The fine rust dust will get through the filters. So there is a chance or four to catch more of the dust. When they are only making it a few miles at a filter, just pull the most clogged up front and go again. Again, it is when doing stuff you shouldn't. Using fuel tanks that are full of rot and no sane car guy would even think of using it.

 

[Timmy390]

Pull the filter and the 3" of hose.
Watch the show, that's what they do.
When dealing with a rusty tank that you should not be trying to use, it does make sense. The fine rust dust will get through the filters. So there is a chance or four to catch more of the dust. When they are only making it a few miles at a filter, just pull the most clogged up front and go again. Again, it is when doing stuff you shouldn't. Using fuel tanks that are full of rot and no sane car guy would even think of using it.

On the show it did help or seemed to....... First filter was nasty, second was dirty third was looking good and the last 2 looked like clean gas. Just saying......

Tim

 

[ba123]

I'd say prefilter before pump and filter after pump. Any more than that you're just giving yourself too many things to diagnose when not running correctly.

There's no reason for it and no reason to have one for each tank before the selector unless that's easier and if so, then keep those and then just one after the pump for 3 total.

Edit...after thinking, I like my scenario #2 so you can see which tank is clogging the filter. So, one for each tank prefilter, then main filter after pump.

Oh, and if your carb has one built in, then don't add a post pump unless your carb says to. It's just too much.

 

[Steve83]

The fine rust dust will get through the filters. So there is a chance or four to catch more of the dust. When they are only making it a few miles at a filter, just pull the most clogged up front and go again.

I'd still do finer parallel filters, which would both catch more of the fine rust, AND take longer to totally clog up, without having to stop every mile. You'd just get the full life from each filter and the better filtration without the hassles.

 

[DirtDonk]

Logically that might seem correct. But if you ever watch the show and what they do, you realize they rarely get more than 10 miles at a stretch anyway. Usually less than three.
One thing or another always stops them. I remember that episode with the filters, but don’t remember how many of the unplanned stops were filter related, or involved other issues.

They have an epic reputation for leaving a safe haven when having charging systems that don’t work, gas tanks that don’t hold gas, and all sorts of similar maladies.
Radiators that don’t hold coolant, but they always seem to find a reason to throw antifreeze in there instead of just water. That way, they are sure to pollute every neighborhood they drive through because they keep dumping gallons of antifreeze on the pavement, instead of just water.
That part drives me nuts!
They have distributors that don’t advance, floors that don’t keep out dust or rain, windows that don’t always roll up, exhaust that dumps into the cabin, and the typical headlights that don’t work. And which they rarely seem to notice weren’t working until after dark.
Basically because they miss all these things during the pre-check. Because they rarely do a pre-check!

You get the picture…

 

[bigmuddy]

Logically that might seem correct. But if you ever watch the show and what they do, you realize they rarely get more than 10 miles at a stretch anyway. Usually less than three.
One thing or another always stops them. I remember that episode with the filters, but don’t remember how many of the unplanned stops were filter related, or involved other issues.

They have an epic reputation for leaving a safe haven when having charging systems that don’t work, gas tanks that don’t hold gas, and all sorts of similar maladies.
Radiators that don’t hold coolant, but they always seem to find a reason to throw antifreeze in there instead of just water. That way, they are sure to pollute every neighborhood they drive through because they keep dumping gallons of antifreeze on the pavement, instead of just water.
That part drives me nuts!
They have distributors that don’t advance, floors that don’t keep out dust or rain, windows that don’t always roll up, exhaust that dumps into the cabin, and the typical headlights that don’t work. And which they rarely seem to notice weren’t working until after dark.
Basically because they miss all these things during the pre-check. Because they rarely do a pre-check!

You get the picture…

But if they did all those pre-checks would still have a show!

 

[ntsqd]

I quit watching shows like that. Seemed like they went out of their way to create problems, and maybe even were making them pre-disposed to happen before filming.

As to how many filters to use, 2. Like Mr. Bowsher said, a pre-filter, be it a sock on the end of the pick-up tube or an inexpensive inline filter before any pumps or valves, and a second, finer filtering filter before the induction. I also happen to really like and use those GM EFI filters. I prefer to buy the Wix 33481 and I use anodized adapter fittings so that they won't rust from the trace water that is always in alcohol blended gasoline.

Can buy a 4 micron version of those marine water separating spin-on filters. I am pondering replacing the OEM filter on the FSB with one of those assemblies.

 

[blubuckaroo]

Ford Diehard, yes you can have too many filters.
*More than one isn't going to make your fuel any cleaner.
*More than one makes troubleshooting more difficult.
*any filter between the tank and mechanical pump will create a low suction pressure and increase the likelihood for vapor-lock. Remember... lower pressure also lowers the fuel's boiling point.

The best thing to do is toss the teenie in-carb filter on your Q-Jet, and get a barbed to fit. Then you can run a decent in-line filter.

 

[Steve83]

But if you ever watch the show…

I don't, and it doesn't sound like I ever will. Sounds like a bunch of DAs show off their stupidity, and setting a lot of really bad examples, making us gearheads look bad.

Seemed like they went out of their way to create problems, and maybe even were making them pre-disposed to happen before filming.

That's the impression I got from his description of the show. I really enjoy the original English "Top Gear" with Jeremy (How hard can it be?), Richard (Hamster), & James (Cpt. Slow), and their new series "The Grand Tour". They specifically set up "challenges" for shows, but then they're left to actually solve the problems without much visible production or interference (but a LOT of antagonizing each other). The Bolivia and Botswana episodes are both hilarious & inspiring.

 

[bmc69]

I run a 20 microns before my electric fuel pump (per fuel pump instructions), and 10 after, per sniper instructions

Same here. But the one I run after is a full-size marine spin on filter. I've laffed and laffed over the last 40 years at people that have fuel filtration issues.