Fuel Filter - The 1947 - Present Chevrolet & GMC Truck Message Board Network

kaycee · 01-17-2008, 02:59 PM

What in line fuel filter do you guys run?I have been running the Fram G-3 but would like something not as bulky and not a glass one either.And do you run it before or after the fuel pump,Thanks and have a great evening

Longhorn Man · 01-17-2008, 03:40 PM

run the filter after the pump. Putting it before can cause, or agrivate a vapor lock condition.

Bob 68327 · 01-17-2008, 03:41 PM

So.Cal.Super · 01-18-2008, 05:04 AM

Quote:

Originally Posted by Longhorn Man

run the filter after the pump. Putting it before can cause, or agrivate a vapor lock condition.

Didn't know that. I installed mine before, same as I run on my dune buggy to keep trash out of the pump.

here is a link to a recent fuel filter thread.

http://67-72chevytrucks.com/vboard/s...d.php?t=272848

Longhorn Man · 01-18-2008, 06:23 AM

a mechanical pump can handle small bits of junk.
Liquid under pressure boils at a higher point. We all know this... that's why the cooling system is pressurized.
However, a liquid in a partial vacume, boils at a LOWER temp than normal. Anyone who has done any seriouse mountain climbing should know this.
Looking at the traditional fule system on these trucks, there is a tank, line, pump, line, carb. (filter in the carb as original) The fuel in the fuel line between the tank and pump is under partial vacume. You install a restriction in that line (filter) then the pressure drops even more when you get between the filter and pump. With that reduced pressure, it can be enough to cause vapor lock... or make it worse.

So.Cal.Super · 01-18-2008, 06:46 AM

good to know fo future ref. if I have problems I know where to look. next time I replace the rubber lines. I will see if I can mount it after the pump.

thanks.

Sweet72 · 01-18-2008, 09:10 AM

I understand the theory Andy, but If it was that much of a vacuum, wouldn't the rubber lines collapse? Ok, I realize that were not talking psi , but inches of mercury when it comes to the effects of atmospheric pressure on boiling point of a liquid, but does it really make that much difference in a fuel line to give it serious consideration? Am I over analyzing?

Longhorn Man · 01-18-2008, 11:42 AM

the way I look at it, they start to get vapor lock when the temps get in the 60's, every little bit helps... or hurts.

Sweet72 · 01-18-2008, 12:01 PM

Every little bit helps or hurts???

I'm glad we got that cleared up...

Longhorn Man · 01-18-2008, 12:09 PM

I mean every little bit in one way helps, in the other way hurts.

jimfulco · 01-18-2008, 12:12 PM

I use the Wix 33003 for 3/8" line. It's clear plastic, not glass.

5/16" line takes a 33002.

Sweet72 · 01-18-2008, 12:26 PM

Quote:

Originally Posted by Longhorn Man

I mean every little bit in one way helps, in the other way hurts.

I know, my smart a$$ sense of humor is always getting me in trouble.

Dingfodgy · 01-18-2008, 01:20 PM

Looking at the traditional fule system on these trucks, there is a tank, line, pump, line, carb. (filter in the carb as original) The fuel in the fuel line between the tank and pump is under partial vacume. You install a restriction in that line (filter) then the pressure drops even more when you get between the filter and pump. With that reduced pressure, it can be enough to cause vapor lock... or make it worse.[/QUOTE]

Out here in the soggy NW- vapor lock is not very prevalent like it is in the southern or central states where summertime temps can be in the 90's or higher for days on end.From my experience, what Andy is saying is true when dealing with stock mechanical fuel pumps. However, if you're running or plan on running an electric pump, then you would want to run the filter before the pump. The negative affects of pulling a vacuum on the fuel for the few inches between the pump and filter will very much be negated by the positive aspects of the rest of the fuel system being pressurized to 5-7 psi. For this reason, I run an Aeromotive canister style filter immediately before my Holley "Red" electric pump. Both of which are mounted on the frame rail a foot or so forward of my under bed fuel tank.

72BLUZ · 01-18-2008, 01:39 PM

here is the one i am trying. just installed it. have approx 150 miles on it!

chev74 · 01-18-2008, 02:51 PM

Quote:

Originally Posted by jimfulco

I use the Wix 33003 for 3/8" line. It's clear plastic, not glass.

5/16" line takes a 33002.

WIX is my choice. Fuel and Oil filter. I have asked many old men, they all say WIX

01-17-2008, 02:59 PM	#1
kaycee Registered User Join Date: Jan 2000 Location: Wyoming USA Posts: 2,445	Fuel Filter What in line fuel filter do you guys run?I have been running the Fram G-3 but would like something not as bulky and not a glass one either.And do you run it before or after the fuel pump,Thanks and have a great evening __________________ 2001 Silverado K-1500 2005 FXDWG stage3 69 CHEVY Short/Step 327/4L60 373 posi 63 IMPALA 327 Last edited by kaycee; 01-17-2008 at 03:01 PM.

01-17-2008, 03:40 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Fuel Filter run the filter after the pump. Putting it before can cause, or agrivate a vapor lock condition.

01-17-2008, 03:41 PM	#3
Bob 68327 72 Chevelle Club Join Date: Jun 2007 Location: Newton , Iowa Posts: 2,052	Re: Fuel Filter __________________ I Have The Right To Remain Silent,But Lack The Ability 1972 Chevelle ... Mine 2006 Trailblazer... Hers 2002 Buick century ... Kids 2002 K1500 Z-71 EXT CAB ... Daily Driver 2005 Rockwood Roo ... For Camping 1974 Harley-Davidson XLH Sportster 84'' stroker

01-18-2008, 06:23 AM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Fuel Filter a mechanical pump can handle small bits of junk. Liquid under pressure boils at a higher point. We all know this... that's why the cooling system is pressurized. However, a liquid in a partial vacume, boils at a LOWER temp than normal. Anyone who has done any seriouse mountain climbing should know this. Looking at the traditional fule system on these trucks, there is a tank, line, pump, line, carb. (filter in the carb as original) The fuel in the fuel line between the tank and pump is under partial vacume. You install a restriction in that line (filter) then the pressure drops even more when you get between the filter and pump. With that reduced pressure, it can be enough to cause vapor lock... or make it worse.

01-18-2008, 06:46 AM	#6
So.Cal.Super It'll Buff Out! Join Date: Apr 2007 Location: San Diego Posts: 603	Re: Fuel Filter good to know fo future ref. if I have problems I know where to look. next time I replace the rubber lines. I will see if I can mount it after the pump. thanks. __________________ "Instructions are just another mans opinion" Become a Supporting Member http://67-72chevytrucks.com/vboard/payments.php Man Card Rules http://67-72chevytrucks.com/vboard/s...d.php?t=634550 72 Chevy Cheyenne Super 400 LWB

01-18-2008, 09:10 AM	#7
Sweet72 Registered User Join Date: Nov 2003 Location: Alexandria, VA Posts: 1,534	Re: Fuel Filter I understand the theory Andy, but If it was that much of a vacuum, wouldn't the rubber lines collapse? Ok, I realize that were not talking psi , but inches of mercury when it comes to the effects of atmospheric pressure on boiling point of a liquid, but does it really make that much difference in a fuel line to give it serious consideration? Am I over analyzing? __________________ '72 GMC SWB C1500 Custom, frame-off in progress. 383 SBC, 9:1CR, Comp Cams XE262H, Scat internal balanced crank, Eagle SIR 6" rods, Keith Black dish pistons, Dart Iron Eagle 72/180 heads, Weiand Stealth intake, Stewart stage I water pump, Holley 4bbl vac sec, TH350 with B&M Shift Improver Kit. 12 bolt positraction.

01-18-2008, 11:42 AM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Fuel Filter the way I look at it, they start to get vapor lock when the temps get in the 60's, every little bit helps... or hurts.

01-18-2008, 12:01 PM	#9
Sweet72 Registered User Join Date: Nov 2003 Location: Alexandria, VA Posts: 1,534	Re: Fuel Filter Every little bit helps or hurts??? I'm glad we got that cleared up... __________________ '72 GMC SWB C1500 Custom, frame-off in progress. 383 SBC, 9:1CR, Comp Cams XE262H, Scat internal balanced crank, Eagle SIR 6" rods, Keith Black dish pistons, Dart Iron Eagle 72/180 heads, Weiand Stealth intake, Stewart stage I water pump, Holley 4bbl vac sec, TH350 with B&M Shift Improver Kit. 12 bolt positraction.

01-18-2008, 12:09 PM	#10
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Fuel Filter I mean every little bit in one way helps, in the other way hurts.

01-18-2008, 12:12 PM	#11
jimfulco Registered User Join Date: May 2003 Location: Shreveport LA Posts: 3,170	Re: Fuel Filter I use the Wix 33003 for 3/8" line. It's clear plastic, not glass. 5/16" line takes a 33002.

01-18-2008, 01:20 PM	#13
Dingfodgy Lemme show you something!! Join Date: Apr 2007 Location: St.Helens, OR. Posts: 876	Re: Fuel Filter Looking at the traditional fule system on these trucks, there is a tank, line, pump, line, carb. (filter in the carb as original) The fuel in the fuel line between the tank and pump is under partial vacume. You install a restriction in that line (filter) then the pressure drops even more when you get between the filter and pump. With that reduced pressure, it can be enough to cause vapor lock... or make it worse.[/QUOTE] Out here in the soggy NW- vapor lock is not very prevalent like it is in the southern or central states where summertime temps can be in the 90's or higher for days on end.From my experience, what Andy is saying is true when dealing with stock mechanical fuel pumps. However, if you're running or plan on running an electric pump, then you would want to run the filter before the pump. The negative affects of pulling a vacuum on the fuel for the few inches between the pump and filter will very much be negated by the positive aspects of the rest of the fuel system being pressurized to 5-7 psi. For this reason, I run an Aeromotive canister style filter immediately before my Holley "Red" electric pump. Both of which are mounted on the frame rail a foot or so forward of my under bed fuel tank. __________________ '67 CST-10 LWB ("Crusty") SOLD '67 GMC SWB ("Murdock") 2000 K1500 Suburban ("Betty") '95 BMW 325i ("Joy")

01-18-2008, 01:39 PM	#14
72BLUZ Registered User Join Date: Nov 2006 Location: lafayette, ga. Posts: 832	Re: Fuel Filter here is the one i am trying. just installed it. have approx 150 miles on it! __________________ Freedom is never more than one generation away from extinction. We didn't pass it to our children in the bloodstream. It must be fought for, protected, and handed on for them to do the same.... Ronald Reagan



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