Author Topic: Cadillac Q-jet 7040230 - with photos!  (Read 144 times)

Offline Glutenfreecarbs

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Cadillac Q-jet 7040230 - with photos!
« on: May 07, 2021, 11:20:14 AM »
Just wanted to show off my winter carburetor: a 1970 Cadillac unit, modified with electric choke, Chevy throttle linkage, and a special adapter for 3/8" fuel line. It's been a great daily driver, and very simple to work on!

(Mods: please delete my previous thread, I broke the embedded images while playing with sizing...)








Offline Kenth

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Re: Cadillac Q-jet 7040230 - with photos!
« Reply #1 on: May 07, 2021, 01:15:57 PM »
Look here:

Offline Cliff Ruggles

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Re: Cadillac Q-jet 7040230 - with photos!
« Reply #2 on: May 08, 2021, 05:52:03 AM »
Good tip on installing the clip thru the holes in the float arm.

Another good tip is to NEVER use a brass float in a Quadrajet, especially the early design with poorly located short hinge pin.

That design was NOT good from day one and doesn't provide enough leverage on the N/S assembly for good fuel control.  Makes things even worse to come along and put a heavy and much smaller brass float in place.

I've replaced hundreds of brass floats in those carbs sent here from customers having fuel control issues.  The even make another type of brass float with the arms soldered on top that are even more hopeless!

We've also ran into issues with current production brass floats leaking at the soldered joints so avoid them in other models of carbs as well, like 2 JET, AFB's, etc........

Offline Glutenfreecarbs

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Re: Cadillac Q-jet 7040230 - with photos!
« Reply #3 on: May 08, 2021, 10:57:57 AM »
Thanks for the pointers! I've always used brass floats because I just don't know which suppliers or materials of plastic floats to trust. However, I installed one of Cliff's floats from his "SR Rebuild Kit" last night, and I was impressed by how light and rigid it felt. Maybe it's time to change my ways...

Offline Cliff Ruggles

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Re: Cadillac Q-jet 7040230 - with photos!
« Reply #4 on: May 09, 2021, 03:34:41 AM »
Zero failures with the late style closed cell nitrophyl floats to date. 

Brass floats are not the correct weight or buoyancy and I've seen scores of them fail over the years, especially this newer production stuff.  I suspect the ethanol in the fuel may eat the solder out of the seams, or they are just junk right to start with.......