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The (original) Quadrajet carburetor on my '66 Toronado has developed the classic problem of leaking internally and losing its "prime" and then being very difficult to start. It's progressed to the point where a repair is definitely necessary. So, I'm looking to re-seal the plugs/seals on the underside of the carburetor/float bowl. Although there are some more exotic repair methods, I'm planning the simple approach of applying an epoxy to the exterior of those plugs/seals.
My question is what is best epoxy to use. There are issues of heat, cold/hot/cold cycling, maybe vibration, etc., but the biggest problem is compatibility with (10%) ethanol-gasoline. What is best epoxy to use for a repair that will hopefully do the job the first time around and then last a very long time, ideally forever.
Thanks for your help.
developed the classic problem of leaking internally and losing its "prime" and then being very difficult to start.
Are you sure the plug wells are leaking? My QJ is similar when it sits for a while - long cranking needed to fill the fuel bowl - and I am certain there are no leaks. I just pour a small amount of gasoline into the float bowl vent using a large syringe and it fires right up.
Also, the QJet rebuild kits have a secondary metering well gasket that is supposed to help with sealing leaks.
To answer your question, my research found a product called Seal All is best for use on gasoline leaks. It's available at most auto parts stores and hardware stores. I have not used it on a QJet so I can't comment on how it would hold up.
Last edited by Fun71; February 20th, 2023 at 01:28 PM.
The (original) Quadrajet carburetor on my '66 Toronado has developed the classic problem of leaking...
I'm not sure if there's any other way to be 100% certain of a leak at the well plugs other than to remove the carb, place it (w/ fuel inside) on an elevated stand w/ a paper towel underneath & allow it to set overnight examining for the tell-tale 'wet-spot'.
The (original) Quadrajet carburetor on my '66 Toronado has developed the classic problem of leaking internally and losing its "prime" and then being very difficult to start. It's progressed to the point where a repair is definitely necessary. So, I'm looking to re-seal the plugs/seals on the underside of the carburetor/float bowl. Although there are some more exotic repair methods, I'm planning the simple approach of applying an epoxy to the exterior of those plugs/seals.
My question is what is best epoxy to use. There are issues of heat, cold/hot/cold cycling, maybe vibration, etc., but the biggest problem is compatibility with (10%) ethanol-gasoline. What is best epoxy to use for a repair that will hopefully do the job the first time around and then last a very long time, ideally forever.
Thanks for your help.
I have Cliff Ruggles book on the QJets and he says that these original 66' QJ's have a bunch of problems. At this point though, has yours ever been previously rebuilt? If so, they may have dealt with the classic typical 66' issues already.
I guess if you want to take the simplest approach, clean off as much as the old epoxy as you can and use the "Marine-Tex" epoxy to re-seal it. That's the stuff all the really great rebuilders use.
As a side note though, I've spoken with several of the really great rebuilders and they all say the same thing about the epoxy. If there's a leak, epoxy won't fix it as, over time, the heating and cooling cycles just make the leak re-appear. I'd say start with Vintage Chief's advice and see if the well plugs are indeed leaking before proceeding.
The 1966-67 Qjets are the only ones that have the sheet metal well plugs that ARE prone to leaking. The only Qjet I've ever owned that leaked was from my 67 Delta. Glue and foam pads are not long-term solutions. I used these machined well plugs with O-rings. Note that losing fuel when sitting is NOT necessarily a sign of leaking. Fuel evaporates. Be sure this isn't your real problem before tearing into the carb.
I'm not sure if there's any other way to be 100% certain of a leak at the well plugs other than to remove the carb, place it (w/ fuel inside) on an elevated stand w/ a paper towel underneath & allow it to set overnight examining for the tell-tale 'wet-spot'.
^^^THIS^^^
If you disassemble the carburetor far enough to do this you've already gone 1/2 way to rebuilding it. MAW finish the job and reassemble the carburetor and tune it. Even after an amateur rebuild you'll probably find it starts and drives much better.
Thanks for all the different responses - I guess it's time for me to respond, and I'll do a group response assuming it will be seen by all.
This is my 2nd 1966 Toro, and both have had carb issues, primarily float bowl leakage. I'm not totally certain what all was done for which. I did try the foam rubber plug, and later found it was dried up and shrunk - maybe newer plugs are different material and hold up better, but I think not to my liking today.
I think the first Toro's carb was eventually replaced with Delco-Rochester #7036687 - I still have the original 7026250 in the new box - I did save some parts from that car before junking it, but I didn't think to save that new carburetor.
The second/current Toro's carb has been "professionally" rebuilt, and I do remember its packing list detailing several upgrades. As to current leak in float bowl, it started several years ago with hard starting after 1-2 weeks of sitting; it has gotten worse to the point of leaking empty over 6-8 hour duration of a car show, and it's really embarassing to have to crank and crank and crank with car show people listening/watching to see what's going on. A leak test is certainly a good idea just to prove my suspicions - I will possibly do depending on what I see at disassembly.
As for sealants, I do notice that the SealAll has both resistance to gasoline and alcohol - of course, they only say resistance. And other epoxys seem to make statements for gasoline, but nothing for alcohol.
At least for now, I'm inclined to proceed with Joe's plugs and O-rings - Joe, can you please direct me as where to find. I looked at Quadrejet Power website, but was surprised that this is not a source especially considering all the Q-Jet products they have.
And, as for a complete rebuild, everything else is working just fine - good idle, good performance and gas mileage, clean exhaust, etc. I have done some rebuilds in the past, but I'd just as soon leave well enough alone - if it ain't broke, you can't fix it.
Once again, thanks to all.
At least for now, I'm inclined to proceed with Joe's plugs and O-rings - Joe, can you please direct me as where to find. I looked at Quadrejet Power website, but was surprised that this is not a source especially considering all the Q-Jet products they have.
Next time, type quadrajet well plugs into Google. You'll get this link to the o-ring plugs.
And those foam pads are worthless. Don't waste your time with that or with epoxy. Every Qjet I've ever disassembled that someone had previously glopped epoxy onto had the epoxy loose and certainly not sealing anything.
Next time, type quadrajet well plugs into Google. You'll get this link to the o-ring plugs.
And those foam pads are worthless. Don't waste your time with that or with epoxy. Every Qjet I've ever disassembled that someone had previously glopped epoxy onto had the epoxy loose and certainly not sealing anything.
Hey Joe,
Have a look at the home page for that company (it's been like this for at least a year now):
"We are temporarily closed due to unforeseen circumstances.No orders will be accepted at this time.
We appreciate your support and hope to have the opportunity to serve you again.
Yeah, it does suck really. They have a great collection of unique Quadrajet parts that only seem to be available through them. I hope they get up and running again.
February 20th, 2023, 12:12 PM
