Best way to flush a tank? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

LeDevil · 10-10-2008, 01:48 AM

Just curious if and how any of you flushed out your old gas tanks. Today my truck almost left me, my fiancee, and my 1 month old daughter stranded. My old fuel filter was flat out CLOGGED! with what appeared to be rust and other chunks of random stuff. I put a new fuel filter in it and it's working pretty well but I don't wanna risk being stranded. So how did you guys flush your fuel tanks? Thanks LeDevil

**El Jay** · 10-10-2008, 02:41 AM

For the time being, put in a steel, inline filter with springy clamps, between the fuel pump & carburetor. The CarQuest part # for a 3/8" inline filter is 86033.
Throw a couple of extra filers and a pair of pliers in the glove box.

Pulling and cleaning the tank is nice, if you have the time to take the truck out of service long enough to do it. (It took me almost 3 days to chemically clean my boat fuel tanks).

Anyhow, if the truck is driven regularly, you'll eventually get all the crud out of the tank & trapped in the filter(s).
This is certainly not the most efficient way to do it, but it works & it's cheap.

Just my .02.

Longhorn Man · 10-10-2008, 05:28 AM

pull it out and take it to a radiator shop.

68gmsee · 10-10-2008, 08:50 AM

Before you yank it out and take it to a radiator shop, call them first. Depending on where you live, some of them won't touch fuel tanks.

The filter idea is okay if it's not extremely rusted or scaled. If it's in real bad shape, I'd invest in a new one and either seal it or have it sealed if you can find a place that does this.

I bought a new one and it sat for 5 years untreated and that's why I'm using an inline filter on mine like El Jay mentioned. The only difference is, I placed it between the tank and fuel pump. This way it catches all the crud before it gets to the fuel pump.

airdale94 · 10-10-2008, 11:34 AM

Quote:

Originally Posted by Longhorn Man

pull it out and take it to a radiator shop.

Actually anyplace with a hot tank can boil it out. Radiator shops get the most business doing this as they are the ones that will patch them up also. If they are willing.

Myself · 10-10-2008, 11:39 AM

I have had good luck with hot soapy water and a 3 foot length of chain. Obviously you want to remove the sender first. And it's much easier to shake if you have a friends help. The chain will knock all the loose rust off and the soap will clean the inside. Rinse it out thouroughly then empty it. Allow it to sit in the sun for about a day to dry out.

68gmsee · 10-10-2008, 11:49 AM

Quote:

Originally Posted by airdale94

Actually anyplace with a hot tank can boil it out. Radiator shops get the most business doing this as they are the ones that will patch them up also. If they are willing.

Not so... In my area we had one radiator shop that did boiling out of radiators. I took the old tank to them (years ago before I bought the new one) and they said they didn't do fuel tanks.

This may have changed now, but I would still call first just to be on the safe side.

mr48chev · 10-10-2008, 12:09 PM

I have pressure washed a couple of them with fair luck.

I agree with 68gmsee, put the inline filter between the tank and the fuel pump to keep crud out of the pump. I've done this on all of my old cars for the past 26 years ever since I killed a fuel pump by leaving a gas cap sitting on the pump at the Grand Teton national park lodge gas station in 1982.

If you spot a 76/80 rear wheel drive Cadillac Seville in a wrecking yard they have a nice fuel filter that has a screw on housing an a bracket to mount it sitting just in front of the tank with the electric fuel pump on the drivers side. It takes a readily available cartridge that costs about the same as a 3/8 inline filter.

LeDevil · 10-10-2008, 12:45 PM

Cool thanks guys, I went and picked up 2 more filters today so now there's a total of 3 in my glove box.
Mr48Chevy I'll go to All American today and look for a Cadillac like you mentioned.

68gmsee · 10-10-2008, 04:56 PM

Quote:

Originally Posted by LeDevil

..... so now there's a total of 3 in my glove box.

I got caught without a spare last week. It's the second time I've had to replace it in the last 1-1/2 yrs. and forgot to get a spare last time.

I was on my way back home (10 miles out) when it started bogging on me. I knew immediately what it was. I was able to slow down to a snail crawl and limp it home. Took about 30+ minutes to go the 10 miles.

I've got a spare now!

**WorkinLonghorn** · 10-10-2008, 09:21 PM

The only thing I'd add to this is that if you aren't going to clean it out,then besides an extra filter and a spare,make sure that the screen "sock" filter at the fuel pick-up (in the tank) is good or replace it.

Longhorn Man · 10-10-2008, 10:58 PM

there is no point in putting a tank in a boil out tank, boiling them out will not remove any rust at all.
Many people think it does, but it does not.
A properly equipped rad shop will start off by running the steam cleaner on it, flushing it for an hr or two. This will knock off all the rust in a lightly rusted tank, and most of it in a medium to heavily rusted tank. On real bad ones, they will cut the tank in half, remove the rust mechanicly, and weld it back up and seal it. Usually after steaming it, they should seal it. And if they use any harsh chemicals, they better seal it.
we do this day in and day out where I work.

As for the fuel filter before the pump. If it is a mechanical pump, then a little dirt/rust won't hurt it. However, putting the filter bevore the pump can make a vapor lock condition worse, or if your ride is boarderline vapor locking, it will cause it.

10-10-2008, 01:48 AM	#1
LeDevil A new C10 Addict! Join Date: Oct 2008 Location: Vancouver, Wa Posts: 105	Best way to flush a tank? Just curious if and how any of you flushed out your old gas tanks. Today my truck almost left me, my fiancee, and my 1 month old daughter stranded. My old fuel filter was flat out CLOGGED! with what appeared to be rust and other chunks of random stuff. I put a new fuel filter in it and it's working pretty well but I don't wanna risk being stranded. So how did you guys flush your fuel tanks? Thanks LeDevil

10-10-2008, 02:41 AM	#2
El Jay Gone to greener pastures Join Date: May 2007 Location: Gateway to the Delta Posts: 7,354	Re: Best way to flush a tank? For the time being, put in a steel, inline filter with springy clamps, between the fuel pump & carburetor. The CarQuest part # for a 3/8" inline filter is 86033. Throw a couple of extra filers and a pair of pliers in the glove box. Pulling and cleaning the tank is nice, if you have the time to take the truck out of service long enough to do it. (It took me almost 3 days to chemically clean my boat fuel tanks). Anyhow, if the truck is driven regularly, you'll eventually get all the crud out of the tank & trapped in the filter(s). This is certainly not the most efficient way to do it, but it works & it's cheap. Just my .02. __________________ '69 Chevy 1/2 T LWB Stepper: Daily Beater '72 GMC 3/4 T Fleet: Another Daily Beater '72 Plymouth Gran Coupe: ? "Ah women. They make the highs higher and the lows more frequent." Friedrich Nietzsche "Never kick a fresh turd on a hot day." Harry S. Truman GUN CONTROL: Never having to say, "I missed you." Always fire two warning shots into your attacker's chest area before putting a bullet between his eyes. Paraphrased from Louis Awerbuck

10-10-2008, 05:28 AM	#3
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Best way to flush a tank? pull it out and take it to a radiator shop.

10-10-2008, 08:50 AM	#4
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: Best way to flush a tank? Before you yank it out and take it to a radiator shop, call them first. Depending on where you live, some of them won't touch fuel tanks. The filter idea is okay if it's not extremely rusted or scaled. If it's in real bad shape, I'd invest in a new one and either seal it or have it sealed if you can find a place that does this. I bought a new one and it sat for 5 years untreated and that's why I'm using an inline filter on mine like El Jay mentioned. The only difference is, I placed it between the tank and fuel pump. This way it catches all the crud before it gets to the fuel pump.

10-10-2008, 11:39 AM	#6
Myself Registered User Join Date: Oct 2005 Location: Northern Arkansas Posts: 1,131	Re: Best way to flush a tank? I have had good luck with hot soapy water and a 3 foot length of chain. Obviously you want to remove the sender first. And it's much easier to shake if you have a friends help. The chain will knock all the loose rust off and the soap will clean the inside. Rinse it out thouroughly then empty it. Allow it to sit in the sun for about a day to dry out.

10-10-2008, 12:09 PM	#8
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 15,411	Re: Best way to flush a tank? I have pressure washed a couple of them with fair luck. I agree with 68gmsee, put the inline filter between the tank and the fuel pump to keep crud out of the pump. I've done this on all of my old cars for the past 26 years ever since I killed a fuel pump by leaving a gas cap sitting on the pump at the Grand Teton national park lodge gas station in 1982. If you spot a 76/80 rear wheel drive Cadillac Seville in a wrecking yard they have a nice fuel filter that has a screw on housing an a bracket to mount it sitting just in front of the tank with the electric fuel pump on the drivers side. It takes a readily available cartridge that costs about the same as a 3/8 inline filter.

10-10-2008, 12:45 PM	#9
LeDevil A new C10 Addict! Join Date: Oct 2008 Location: Vancouver, Wa Posts: 105	Re: Best way to flush a tank? Cool thanks guys, I went and picked up 2 more filters today so now there's a total of 3 in my glove box. Mr48Chevy I'll go to All American today and look for a Cadillac like you mentioned.

10-10-2008, 09:21 PM	#11
WorkinLonghorn Senior Member Join Date: Dec 2006 Location: Studio City, Calif. Posts: 2,861	Re: Best way to flush a tank? The only thing I'd add to this is that if you aren't going to clean it out,then besides an extra filter and a spare,make sure that the screen "sock" filter at the fuel pick-up (in the tank) is good or replace it. __________________ '69 GMC C2500 Custom Camper, 8 1/2' bed, New GM 350, NP 435 Close Ratio 4spd. Trans., 3.73 Dana-60 open.Camper and Trailer wiring, PS, PB, AC, tach , three gas tanks, 2nd owner, Work-Truck supreme. Best $300 I ever spent.

10-10-2008, 10:58 PM	#12
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Best way to flush a tank? there is no point in putting a tank in a boil out tank, boiling them out will not remove any rust at all. Many people think it does, but it does not. A properly equipped rad shop will start off by running the steam cleaner on it, flushing it for an hr or two. This will knock off all the rust in a lightly rusted tank, and most of it in a medium to heavily rusted tank. On real bad ones, they will cut the tank in half, remove the rust mechanicly, and weld it back up and seal it. Usually after steaming it, they should seal it. And if they use any harsh chemicals, they better seal it. we do this day in and day out where I work. As for the fuel filter before the pump. If it is a mechanical pump, then a little dirt/rust won't hurt it. However, putting the filter bevore the pump can make a vapor lock condition worse, or if your ride is boarderline vapor locking, it will cause it.



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