No more fuel filter nut threads in my 1970 Quadrajet

[Chris G.]

My inline fuel filter holder/nut will no longer tighten hard in the body of my 1970 Quadrajet big block engine. Some of the threads have corroded to metal power disallowing a tight fit and fuel leaks I can't fix. This is a correct part number and date code for my 1970 bib block. Now what do I do? This has been leaking for a while.

[Joe L.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

My inline fuel filter holder/nut will no longer tighten hard in the body of my 1970 Quadrajet big block engine. Some of the threads have corroded to metal power disallowing a tight fit and fuel leaks I can't fix. This is a correct part number and date code for my 1970 bib block. Now what do I do? This has been leaking for a while.

Chris------


This is a VERY common problem with Q-Jets. Once-upon-a-time I was stranded in Tonopah, Nevada for a few days with this problem.

There is a good fix for it, though. Heli-Coil makes a special kit to install a Heli-Coil in the inlet fitting. The kit is quite expensive, though, and really requires some expertise to install without destroying an original carb like yours. Most of the major custom carburetor rebuilders have the kit and the expertise to install the Heli-Coil. I recommend that you seek out one and have the inlet fitting repaired.

[Chris G.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

Joe,

These are fine threads. They have a Heli-Coil that fine?

[Joe L.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

Joe,

These are fine threads. They have a Heli-Coil that fine?

Chris------


Yes, they are very fine threads and, yes, they definitely have a Heli-Coil for it.

[Edward B.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

Search: Heli-coil for Quadrajet

[Patrick H.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

I've had this done, and the repair works well. I had one repaired by sending off the main body after I disassembled it, one repaired when the carb was restored. Odds are that if you send it off, the repairer will also want to recolor your carb body so that you don't have raw metal where the repair is performed.

[John D.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

Chris, Would you like a cheater that will work. Use Loctite 609. Not readily available in auto stores. Buy it on line. Compatible with any kind of fuel. Make sure everything is spotless first.
Sets up in 10 minutes but takes at least 24 hours to harden.
Some like 271 but it's permanent although i am told in time it will wash away with fuel. Don't know if this is 100% true as got it heresay.
I would use the 609. Buy it in smallest container possible. Shake it and apply with a q-tip. John
P.S. I keep it in the ice box in my shop.
My old time favorite is Locttie 545 hydraulic sealant but since your threads are in bad shape I don't think I would use it here.
In the old days I remember we only had a few Loctites. Today there are a ton of them. I am Loctite poor.

[Chris G.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

Patrick, do you remember who you sent your Quadrajet for its Heli-Coil? Thank you also Joe for this info.

[Patrick H.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

Chris,

It was Jerry Luck, who is no longer in business.

I suspect that Eric Jackson and some of the others offer this service.

Patrick

[Joe L.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

Patrick, do you remember who you sent your Quadrajet for its Heli-Coil? Thank you also Joe for this info.

Chris------


I've never used these folks, myself. However, I really like they way they do this repair. I would be extremely fearful of someone doing this by tapping by hand.

http://quadrajetparts.com/service-fuel-inlet-thread-repair-heli-coil-installation-inlet-carburetors-p-356.html?osCsid=c0a5d0acc28b4c18cc94f9e1c4bc5c2e

[Patrick H.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

Jerry used to do them on a Bridgeport in a similar manner.

[Chris G.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

quadrajet parts.com is what I found also in my search. They don't thread it by hand, they support the carb body in a jig and machine the threads in. Sounds like the right way to do it.

[Jim D.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

I haven't this problem in years but a long time ago, there was a company that sold an oversized/self tapping fitting that solved this issue. I've used it many times in the past with great success.

[Joe L.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

I haven't this problem in years but a long time ago, there was a company that sold an oversized/self tapping fitting that solved this issue. I've used it many times in the past with great success.

Jim-------

I think they're still around. In fact, it was one of those things that got me home from Tonopah many years ago. However, I regarded it as a temporary fix and had the carb Heli-Coiled and otherwise rebuilt by Brad Urban's Carb Shop in Ontario, CA. Brad "wrote the book" (both literally and figuratively) on Q-Jets but, unfortunately, he passed away many years ago. I still have the rebuilt carb, though, never installed.

I have found that the self-tapping fittings are very difficult to install "straight-and-true".

[Patrick H.]

Re: No more fuel filter nut threads in my 1970 Quadrajet

I haven't this problem in years but a long time ago, there was a company that sold an oversized/self tapping fitting that solved this issue. I've used it many times in the past with great success.

I tried one. It leaked, then stripped. That was before I knew about the Helicoil fix. Having tried one and now knowing the correct fix, I'd never try one again.