1969 Fuel Filter
Thread Starter
Instructor
Joined: Jul 2003
Posts: 240
Likes: 4
From: Mendon MA
1969 Fuel Filter
Folks,
I just replaced the fuel filter in my 69 vette (350/350). After connecting the top fuel line (the one going to the carb), I can't seem to get it to stop leaking. Is there a special technique to this step? Should I use teflon tape on the threads? Is there something I am missing?
Thanks for the advice (in advance),
Jim
I just replaced the fuel filter in my 69 vette (350/350). After connecting the top fuel line (the one going to the carb), I can't seem to get it to stop leaking. Is there a special technique to this step? Should I use teflon tape on the threads? Is there something I am missing?
Thanks for the advice (in advance),
Jim
Melting Slicks
Joined: May 2009
Posts: 3,079
Likes: 314
2024 C3 of the Year Finalist - Unmodified
We can only assume you have a stock setup. If it did not leak before, then we can assume the 37 degree inverted flare fuel line and fitting is okay, and the only thing that has changed is the new filter. If it is an after market filter, then it is entirely possible that the male flare on the filter outlet does not match the fuel line. If it is a GF-432, then look to make sure both the filter and the flare on the end of the fuel line do not have any ridges, burrs or corrosion. If so, you need to make sure to clean them up with fine wet or dry sandpaper. Make sure the fuel line flare is not cocked on the filter outlet before tightening the nut. It has to be lined up perfectly. Teflon tape on the threads does nothing to prevent fuel leakage. All the fuel should be captured by the inverted flare on the fuel line. No fuel should be anywhere near the threads.
Thread Starter
Instructor
Joined: Jul 2003
Posts: 240
Likes: 4
From: Mendon MA
69 Fuel filter
The new fuel filter is an AC-432 I purchased from Ecklers. The set-up is stock. The fuel line from the carb goes in straight, and screws in nicely(nothing stripped). I tightened it as tight as I could, it leaks when the engine is running. I was hoping there was an equalivent to a teflon tape that I could use.
Jim
Jim
Melting Slicks
Joined: May 2009
Posts: 3,079
Likes: 314
2024 C3 of the Year Finalist - Unmodified
Do yourself a favor and remove the line. Look at the flare under a magnifying glass. Make sure all is well. Look at the filter outlet with a magnifying glass. Something is not right. Last but not least, place the fuel line straight on the filter end first and snug the fitting. Then place it straight into the carb inlet and snug that fitting. Then give both fittings a final snug. They should be tight, but not crazy tight. Forget the tape. Forget silicone. You don't want anything like that ending up in your carb inlet needle and seat.
Thread Starter
Instructor
Joined: Jul 2003
Posts: 240
Likes: 4
From: Mendon MA
69 Fuel Filter
Faster Rat,
Thanks for the great ideas. I will disconnect the line from the carb/filter and inspect. I'll plan on re-attaching the line to the filter first (perfectly straight), then to the carb ourlet. Who whould ever think replacing a fuel filter would be so tough?
thanks again for all your help,
Jim
Thanks for the great ideas. I will disconnect the line from the carb/filter and inspect. I'll plan on re-attaching the line to the filter first (perfectly straight), then to the carb ourlet. Who whould ever think replacing a fuel filter would be so tough?
thanks again for all your help,
Jim
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
Put some grease or anti-sieze between the tubing nut and flare to help you get the tubing nut properly tightened. I always do this with stainless steel brake lines to prevent leaks. One other thought is the flare may be cracked if it is, it's easily repaired with a double flaring tool.
Racer
Joined: Jun 2002
Posts: 281
Likes: 0
From: Brookfield IL
I had exact same problem with mine tonight. I ended up taking it back off, sanding the fuel line flare and the filter seat with a thin scotch brite pad. I just put it back together and no leaks.
I had best luck first attaching fuel line to carb but leave it loose so it can swivel. Then attach fuel line to bottom of fuel filter, hold filter straight with fuel line, and tighten. Then attach fuel line to top of fuel filter and tighten. And then tighten up at carb. Mke sure to use 2 wrenches on filter to get a nice, tight fit.
I had best luck first attaching fuel line to carb but leave it loose so it can swivel. Then attach fuel line to bottom of fuel filter, hold filter straight with fuel line, and tighten. Then attach fuel line to top of fuel filter and tighten. And then tighten up at carb. Mke sure to use 2 wrenches on filter to get a nice, tight fit.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
Heel & Toe
Joined: Jun 2011
Posts: 21
Likes: 1
From: Clinton TN
I bought an ac 432 from Eckler that was a chinese knockoff and when I tightened the top nut it broke off. It looked like it had been glued on. Got my money back and bought 2 on ebay, US made for half the price. It worked fine first time.
Racer
Joined: Jun 2002
Posts: 281
Likes: 0
From: Brookfield IL
That reminds me-- do you guys have an engine bracket holding your filter? I saw a pic of one somewhere I think in the service manual.
I don't have one and am wondering if I should? Right now my filter is just held in place by the 2 steel gas lines.
I don't have one and am wondering if I should? Right now my filter is just held in place by the 2 steel gas lines.
Melting Slicks
Joined: May 2009
Posts: 3,079
Likes: 314
2024 C3 of the Year Finalist - Unmodified
SB is supposed to have one. Attaches to the A.I.R. pump bracket. Shows in the Assembly Instruction Manual. BB does not. Uses the steel lines to support the filter. Your call.
Burning Brakes
Joined: Apr 2007
Posts: 1,186
Likes: 41
From: Pinecrest FL
2015 C3 of the Year Finalist
The 80 something year old guy that rebuilt my carb gave me a small brass washer that had already been flared to match the line...solved all of my leak issues.
Even though my steel line looked fine, it is easier to make the steel seat properly on a brass washer than on another piece of flared steel.
Gary
Even though my steel line looked fine, it is easier to make the steel seat properly on a brass washer than on another piece of flared steel.
Gary
Thread Starter
Instructor
Joined: Jul 2003
Posts: 240
Likes: 4
From: Mendon MA
69 Fuel filter- Giving up
Well I tried it all. I took the system apart, took off the fuel line from the top of the filter and the carb. I checked the flares, cleaned them, they looked great (on the line). I re-attached on the filter first (getting best seat possible), then attached at the carb. I started it up, it leaked at the filter. I took off the lines, I loosely put the lines into the filter and carb, seated them, then tightened. I started it up, it leaked at the filter line again. Now I am wondering if the new AC 432 filter from Ecklers is defective. Does anyone know where I can be guarenteed to get a US made filter? (or a neat brass ring I can use),
Jim (frustrated!!!)
Jim (frustrated!!!)
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
Do you still have the old filter? Ya probably chucked it, huh? If you still have it, try re-installing it, and see if it leaks with the old filter. If it doesn't leak, send the new filter back and ask for a new one. If it leaks with the old filter, you'll know something is wrong with the fuel line or fitting.
Scott
Scott
