[F ROCK]

Rochester Quadrajet, or Carter Quadrajet?
Both of my Carter quadrajets had inlet issues; soft metal.

[jhein]

So here's what I did. (And I did two things at the same time so it's not entirely clear which fixed it, or a little of both)

First, I took it apart and closely examined the flare. It looked perfect. I made sure the fittings were clean and no obvious cracks or other damage. I noticed that the fuel line is not lined up perfectly in line with the inlet. It was angled just a tiny bit to the passenger side. It was too stiff to bend by hand. So I pulled the carb bolts out and attached the fuel line snugging it up with the carb loose so I got a nice seat. Then, with tha carb attached to the line it easily went into place on the manifold.

The other thing I did was to use teflon tape on the threads. I put it on the fuel filter housing/inlet threads as well as the fuel line fitting threads. I made sure to leave the first two threads clear and I did a nice neat job so no loose threads of tape or anything.

I got everything tightened up, not gorrilla tight.

No leaks now.

I kinda feel like it was the proper alignment that did it more than the tape, but I don't know for sure.

Thanks for all the suggestions.

[jhein]

Originally Posted by F ROCK

Rochester Quadrajet, or Carter Quadrajet?
Both of my Carter quadrajets had inlet issues; soft metal.

Rochester

[NeighborsComplaint]

Double flare always. Autozone and others have a flare kit you can borrow with a deposit. Trim the end with a mini tubing cutter from the hardware store and following the instructions to flare. Remember to put the flare nut on first though.

[Joe's Garage]

Like F ROCK, we've owned exactly three Carter-made quadrajets and ALL THREE fuel inlets STRIPPED OUT.

We fixed all three of them using JB Weld and then used them for many years afterwards.

On one carb, we also stripped out the threads for the fuel inlet needle and seat and the threads on two of the screws that retained the top cover. Metal was VERY soft.

Never have stripped the threads on a Rochester.........yet........

We've also always used teflon tape on both the fuel inlet threads and fuel line fittings, leaving the first two or three threads bare, just as OP (jhein) did on his.

I guess we were all taught the same teflon tape procedures back in the day, huh?

Glad you got it figured out!

[Cliff R]

The correct repair is to have a heli-coil installed. It is at least 3 times stronger than the original threads. Any "self-tapping" or expanding fittings will ruin your carburetor.

ALWAYS lubricate the inside of the fuel filter housing where the flare seals. Light oil or grease is fine, but it MUST be able to seal on the inverted flare against the fuel line double flare without trying to twist the fuel filter housing out of the threads instead. Most of these carburetor inlet threads are ruined because folks fail to lubricate the associated parts when you start torquing the piss out of the fuel line nut and not effectively holding the fuel filter housing with a 1" wrench..........Cliff

[78w72]

teflon tape on flared fittings? why? the flare does the sealing, not the threads.

[jhein]

Well, I realized last night that my teflon tape did absolutely nothing. I was hoping to get on here this morning and point out my own error before anyone else did but you guys beat me too it!!

But, that's actually good news because it means my flare, seat and threads are all good, I also understand the need for lubrication. same concept as putting lube on o-rings so they don't bind. Got it.

[Cliff R]

Teflon tape "shreds" and for sure will find it's slippery way into your carburetor. It should NEVER be used anyplace in a fuel system, even on NPT threads......FWIW.......

[Sirrotica]

Originally Posted by 78w72

teflon tape on flared fittings? why? the flare does the sealing, not the threads.

Well we agree on one thing, the flare seals the fluid, the threads have zero sealing effect. If the flared joint leaks, the fluid will run out between the nut and the tubing.

Working in a plastic injection molding shop many years ago, we had maintenance workers that would use teflon tape on flared hydraulic fittings. Other than it does provide a lubricated surface so the threads are lubricated, (no galling), it has no purpose to seal anything. BTW, when you're sealing hydraulic lines the pressure isn't 5 PSI, it's usually 2000-3000 PSI. Double flared joints seal fine at these pressures, 5 PSI is a walk in the park to seal.

The OP was probably correct, that the misalignment of the tube and fitting contributed to the leak, or there was some foreign material in the fitting mating surfaces. (not uncommon in automotive fuel systems).

Glad to hear the problem is solved......

[78w72]

Originally Posted by Sirrotica

Well we agree on one thing, the flare seals the fluid, the threads have zero sealing effect. If the flared joint leaks, the fluid will run out between the nut and the tubing.

Working in a plastic injection molding shop many years ago, we had maintenance workers that would use teflon tape on flared hydraulic fittings. Other than it does provide a lubricated surface so the threads are lubricated, (no galling), it has no purpose to seal anything. BTW, when you're sealing hydraulic lines the pressure isn't 5 PSI, it's usually 2000-3000 PSI. Double flared joints seal fine at these pressures, 5 PSI is a walk in the park to seal.

The OP was probably correct, that the misalignment of the tube and fitting contributed to the leak, or there was some foreign material in the fitting mating surfaces. (not uncommon in automotive fuel systems).

Glad to hear the problem is solved......

im sure we would agree on a lot of things, mechanical & other stuff we cant talk about here... we've just had some different opinions on a couple things, doesnt make either of us wrong, theres usually more than one way to skin a cat.

i used to work for a large injection molding company too that had some GM & ford contracts among many others, had many different positions over the few years i was there.

[Ram Air IV Jack]

Originally Posted by Cliff R

The correct repair is to have a heli-coil installed. It is at least 3 times stronger than the original threads. Any "self-tapping" or expanding fittings will ruin your carburetor.

ALWAYS lubricate the inside of the fuel filter housing where the flare seals. Light oil or grease is fine, but it MUST be able to seal on the inverted flare against the fuel line double flare without trying to twist the fuel filter housing out of the threads instead. Most of these carburetor inlet threads are ruined because folks fail to lubricate the associated parts when you start torquing the piss out of the fuel line nut and not effectively holding the fuel filter housing with a 1" wrench..........Cliff

When you did my 273 Qjet 7 years ago Cliff, the threads were shot and the heli-coil was the only answer. If you knew how many people back in the day used those "self-tapping" fittings to repair stripped out treads in these carbs, you would shudder. I do just thinking about it today!!!

[Longs]

I noticed yesterday that my '67 Quadrajet 7027262 was dripping at the fuel inlet. I saw the same around a month or so ago, wasn't sure if it was the inlet housing to the carb body or the fuel line to the inlet housing, so I loosened the 5/8" fuel line while holding the housing 1" nut, tightened the inlet housing 1" nut a little, reinstalled the fuel line, and tightened that while holding the housing nut. It stopped leaking.

Since I hadn't started the car in a while I thought that I'd just look things over while it was initially warming up, and I saw that the fuel line inlet was dripping again. I loosened the fuel line, tightened the nut, reinstalled, still leaking. I thought that it might be the housing washer so I swapped it and the filter with a new one from a rebuild kit that I got from Cliff but haven't done, put it back together.

Still leaking, seems to be from the fuel line. I removed the line again, removed the housing, noticed that the flare seat in the inlet housing looks a little bit "distorted" and that it wouldn't be the best mating surface for the fuel line flare. Rather than trying to mess around with it or crank it down and mess it up more, I have now ordered a replacement inlet housing from Cliff.

I don't want to repeatedly remove and install the line and housing to the carb body, and I definitely DO NOT want to risk stripping any threads. So to the question at hand: How tightly do you try to make these connections? The inlet housing to carb body readily threads on but once it seats I'm very hesitant to put much torque on it. Should it turn at all once it seats?

I had never heard the "lube the inside of the inlet housing" advice that Cliff posted, but that makes sense. What about lubing the threads where the housing goes into the carb body? My understanding is that those threads are exposed to fuel and that the thin washer is what seals the inlet housing to the carb body.

Thanks for any advice that anyone can provide!

[Longs]

Adding follow-up on my own comment #33 following installation of the new inlet housing that I ordered from Cliff. I removed the old inlet housing, comparing it to the new housing, the part of the housing with the threads that go into the carb body was longer, so that provided more threads to mate with those in the carb body. That would hopefully mean there'd be less chance that it would strip. Was that by design? I believe that the old inlet housing was original to the carb. The new housing came with a fiber gasket. The old gasket was a coated steel, it was magnetic when tested.

I ran the new housing into the carb by hand to make sure that it would go in all the way, and it did. I removed it, sprayed some carb cleaner into the threads in the body to make sure there weren't any foreign particles, then lightly oiled the threads and installed with the fiber gasket, tightening very carefully, not wanting to go to tight. I installed the fuel line with the back of the flare and line lightly lubed. I started it up and it leaked, tried incrementally tightening it several times, couldn't get it to stop leaking, was afraid to over torque it and ruin the carb. I probably fiddled around with it a dozen times.

I removed the housing completely and carefully inspected and cleaned the carb body mating surface, inspecting under magnification, thinking that I have it as clean as it's going to get, no burrs, etc. I thought that I'd try the metal gasket instead; still leaked.

So long story short, I remember seeing somewhere, could have been here, to try two gaskets. I used the fiber gasket against the carb body with the old metal gasket against the nut, tightened it up as much as I dared, reinstalled the fuel line, and NO LEAKS. Maybe the second gasket, especially because it was metal, allowed for more uniform pressure against the carb body, or maybe it was just thicker so it was more forgiving. I didn't run it that long, I will plan to check it again tomorrow, I'm hoping that it's good. I made a note to myself to remember the two gaskets.