1965 Gas Filter Problem

[Edward S.]

I recently had a problem with some bad gas and am replacing things to correct the problem - the last thing I am replacing is the GF-416 gas filter. First of all I ordered one of the new repros which looks great - getting the original NOS 416 off the car was a real buster, all fittings were on real tight, so tight I bent one side of the old filter trying to apply pressure. Once removed I put the new repro on and can not get it to stop leaking, dispite a few tries. Has anyone else with a 396/425 run into the same problem with the repros - if so how did you correct it? I am not too kean on using Teflon on gas fittings. Any help would be appreciated.

[Joe L.]

Re: 1965 Gas Filter Problem

I recently had a problem with some bad gas and am replacing things to correct the problem - the last thing I am replacing is the GF-416 gas filter. First of all I ordered one of the new repros which looks great - getting the original NOS 416 off the car was a real buster, all fittings were on real tight, so tight I bent one side of the old filter trying to apply pressure. Once removed I put the new repro on and can not get it to stop leaking, dispite a few tries. Has anyone else with a 396/425 run into the same problem with the repros - if so how did you correct it? I am not too kean on using Teflon on gas fittings. Any help would be appreciated.

Ed------


The fittings on the original GF-416 filter were NPTF aka "Dryseal". This type of thread should not require sealer. All that I can surmise is that the reproductions use regular NPT thread. This will often not seal without sealer, especially if the fluid being carried is something like gasoline.

Given that yours is leaking and assuming that the fittings are appropriately tightened, I would say that you're going to have to use sealer on the threads. I think if you carefully apply Teflon tape, you can use it both "invisibly" and so that it does not cause any other problems.

[Wayne M.]

Re: 1965 Gas Filter Problem

Ed -- as Joe says, the GF-416 uses Dryseal end fittings (pic below of old NOS, on left -- note row of stamped 'B's along the top flat). What about the fuel line fittings on either side ? Are they the originals ? Are the repop fuel lines designed to seal against a Dryseal ?

[Edward S.]

Re: 1965 Gas Filter Problem

Wayne, I have had the car now for 11 years and the fittings were on the car when I bought it and I assume they are original. Early on when I thought I would try for a Duntov I sold my first born and bought a NOS 416 - thats what I just took off. I am not anywhere near being a mechanic but from what I can see the problem is the rear fitting. The brass front fitting has only one line going into it from the pump it is flaired and has a nut with which to tighten it and the other end of the fitting just threads into the filter - and when I start the car it is bone dry. However the rear fitting is steel and has three lines going into it ( all are bone dry ) The other end of the fitting just also screws into the filter, that connection is where the leakage is running heavy. In taking the old filter out, both myself and a friend of mine could not get it to loosen, so happens another friend was there and got it apart - not before we all thought he was having a heart attack.
I have a lead on a NOS 416 I am trying to get before I mess around with teflon, I will post on how I make out. I want to thank you and Joe for your input.

[Edward S.]

Re: 1965 Gas Filter Problem

Joe and Wayne I thought you might like to know that this afternoon I elected to put the older NOS filter back of the car ( since it was not leaking to begin with ) happy to report that there was no leakage. Car is running great, I am keeping the repro., but if I have to use it in the future I would use Teflon. I would think you were both right, the leakage is most likely the threads
Some friends of mine swear that the repros might be being made in China.
As I said I appreciate your help and I am ready to enjoy the Duntov Display at Wildwood without the aroma of hi-test.

[Dick W.]

Re: 1965 Gas Filter Problem

Ed, you can use Loctite PST or the Permatex equivilent, wipe off the excess when tightened, and no one will know the difference.

[Edward S.]

Re: 1965 Gas Filter Problem

Thanks Dick.