Stripped inlet threads on Quadrajet
#1
Stripped inlet threads on Quadrajet
This morning I smelled stronger gas fumes than normal and upon inspecting the carb I noticed steady drips of gas leaking from the fuel filter housing inlet. I went ahead and tried to unscrew it to take a closer look at the gasket and threads and the thing practically came out by just pulled. The threads are stripped.
I read about three different options for fixing this which was heli coil (out of my price range), a self tapping fitting (interested in this but do not want to have to remove and take apart the carb considering I need it ASAP and it is my daily driver and only car), or just flat removing carb filter (and leaving the FRAM inline that is hooked up between the fuel line and carb) and epoxying it for good. Would epoxying/JB Weld be a safe to use with fuel?
I do not really care for originality as this is just the start of a long project and learning experience. I do not have a lot of tools, time, space or money. Like I mentioned, I need to get it fixed ASAP because it is my main transportation.
Thank you
I read about three different options for fixing this which was heli coil (out of my price range), a self tapping fitting (interested in this but do not want to have to remove and take apart the carb considering I need it ASAP and it is my daily driver and only car), or just flat removing carb filter (and leaving the FRAM inline that is hooked up between the fuel line and carb) and epoxying it for good. Would epoxying/JB Weld be a safe to use with fuel?
I do not really care for originality as this is just the start of a long project and learning experience. I do not have a lot of tools, time, space or money. Like I mentioned, I need to get it fixed ASAP because it is my main transportation.
Thank you
#3
Interesting. I've never seen one like that before. I'd be concerned that you'll chew up the O-rings on the old threads trying to get it inserted.
#4
That's a Tomco style repair fitting. As you tighten it up it expands outward and the o-rings seal the fuel leak. That one is a last resort, because you will often find them tightened enough to crack the fuel inlet area of the carb. When that happens the carb is for all practical purposes junk. Not even a heli-coil can save the threads then.
A self tapping fitting can be installed with carb on car but you must be careful. What you want to do is to tighten the thing about a 1/4 turn at a time and then back off. About every 3rd or 4th time, take it all the way out and clean metal chips out of the threads. Keep doing that until it's fully seated, then remove it and clean all the metal chips out of the thread area so they don't get in your float needle and make all kinds of flooding problems.
If I do a self-tapper, I usually put some type of grease, oil or something in there to help catch the metal chips. Vaseline will work fine. Then spray some brake or carb cleaner in there to get all the grease and metal out before final installation of the self-tapper.
Make sure to get the correct size self-tapper if you go that route. Oldsmobiles take a 3/8" fuel line. Most self-tapper fittings have a nylon gasket to go between the fitting and the fuel inlet.
You can delete the carb inlet filter and just use an inline one. That way you don't have to disturb the self-tapper again.
A self tapping fitting can be installed with carb on car but you must be careful. What you want to do is to tighten the thing about a 1/4 turn at a time and then back off. About every 3rd or 4th time, take it all the way out and clean metal chips out of the threads. Keep doing that until it's fully seated, then remove it and clean all the metal chips out of the thread area so they don't get in your float needle and make all kinds of flooding problems.
If I do a self-tapper, I usually put some type of grease, oil or something in there to help catch the metal chips. Vaseline will work fine. Then spray some brake or carb cleaner in there to get all the grease and metal out before final installation of the self-tapper.
Make sure to get the correct size self-tapper if you go that route. Oldsmobiles take a 3/8" fuel line. Most self-tapper fittings have a nylon gasket to go between the fitting and the fuel inlet.
You can delete the carb inlet filter and just use an inline one. That way you don't have to disturb the self-tapper again.
Last edited by rocketraider; September 10th, 2010 at 07:39 PM.
#5
... About every 3rd or 4th time, take it all the way out and clean metal chips out of the threads. Keep doing that until it's fully seated, then remove it and clean all the metal chips out of the thread area so they don't get in your float needle and make all kinds of flooding problems.
Thank you for the solid info. Exactly what I was looking for.
#6
Do you have any knowlede on this? I found this extended threaded non-tapping fitting which claims "Q-Jet main body castings have threads that are not used by OEM inlet fitting"
http://www.gesslerheadporting.com/gesslerheadporting/ghp.nsf/822dcaaaa26c6da985256dd80023623d/7765a3e3115e42f68525761900081cb9!OpenDocument
http://www.gesslerheadporting.com/gesslerheadporting/ghp.nsf/822dcaaaa26c6da985256dd80023623d/7765a3e3115e42f68525761900081cb9!OpenDocument
#8
I plan on it. I am just trying to get an idea of what are my best options right now. I need to check if it is 7/8" or 1" inlet. They are closed during the weekend so I will give him a call on Monday to try to get it going.
#9
Gessler's part seems like your logical first choice...think about it.
>It utilizes threads that are still intact.....
>Doesn't destroy any threads or cut into the body of the fuel inlet
>Doesn't exert outward pressure on the fuel inlet casting like the O-Ring setup might.
>Doesn't require machine work like Heli-coiling would
>Probably costs the same or less than the alternativee.
If this piece doesn't work then you can move on to the more "destructive/higher" cost measures.
>It utilizes threads that are still intact.....
>Doesn't destroy any threads or cut into the body of the fuel inlet
>Doesn't exert outward pressure on the fuel inlet casting like the O-Ring setup might.
>Doesn't require machine work like Heli-coiling would
>Probably costs the same or less than the alternativee.
If this piece doesn't work then you can move on to the more "destructive/higher" cost measures.
#10
I ordered the 7/8" self tapping long filter inlet and attempted to install it. Came to realize that the threads are so worn on the inlet that the fitting was able slide in and out. No threads made contact. Here is a video of what I am talking about. I decided to clean it out tomorrow and go ahead and JB Weld the original fitting on the carb. I hate to go this route but I dont have time to get it heli coiled and the inlet has a removable nut extension in the front (before the hard fuel line) which will still give me access to the fuel filter if I ever decide to use it.
http://www.youtube.com/watch?v=vCP-Zbp6BpM
http://www.youtube.com/watch?v=vCP-Zbp6BpM
Last edited by yeahbuddy; September 16th, 2010 at 07:48 PM.
#11
Took the the worst case scenario and applied JB Weld around the threads and the lip. I let it dry for 72 hours before even touching it. It solved the problem and it is in there for good. Instantly noticed better idling and accelerating. The surge issue I was having at 50mph stopped as well which makes sense considering it was probably sucking in air bubbles through the leak. I am fortunate enough to have an inlet fitting that has the fuel filter housing on the exterior under a separate nut that the hardline screws into. So although it doesn't look too pretty and it is permanent, I still have access to the original style fuel filter if I ever desire to use it along with the inline setup I got going right now. I feel guilty but I didn't have much money or choices at this point. This should hold me down until I find a decent condition replacement to rebuild.
quadjb.jpg
quadjb1.jpg
quadjb.jpg
quadjb1.jpg
Last edited by yeahbuddy; September 20th, 2010 at 06:38 PM.
#14
Same thing happened to me, thanks for the thread guys, this site helps a lot! @yeahbuddy, if you've replaced that carb and still have it lying around, would you be interested in selling it (looks like a Qjet yes?)...i'm thinking of putting a 4bbl on my cutlass but i'm on a budget!!
thanks again for the info!
thanks again for the info!
#15
Yeahbuddy, are you still using this carb two years later, or at least did you use it for awhile after the repair? I have exactly this same problem and am wondering how the JB Weld held up against the gasoline?
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