: Hi, and help please - 1976 Eldorado 500 c.i w/Quadrajet

08-02-12, 02:06 PM
Im new to the site and the world of Cadillacs. Currently I cannot seem to find the fuel filter on my 76 eldorado (500 Q-Jet). Some people say I'm to young to appreciate the car but it's an inheritage item so I plan on seeing to it that it gets taken care of. I know how these forums work, I've been a member of a jeep forum for 6 years. I doubt I'll be very helpful to you guys but I'd sure appreciate any and all input regarding a severely rough idle and where to find front fender body filler pieces.

Thanks again,


08-02-12, 02:18 PM
Is it fuel injected or carbureted?

08-02-12, 02:36 PM
Quadrajet = 4 bbl carburetor. The fuel filter is in the float bowl inlet fitting. It will be either a sintered bronze plug or a slightly longer pleated paper cylinder - you need to know just which filter fitting your carb has. You may not have another in-line filter.

Figure out the cubic inches of your engine and we'll move this to the right engine forum - I think yours is a 500 cubic inch V-8.

You need to find the large paperback book on Quadrajets by Doug Roe - everything you ever wanted to know and how to do it with QJ's - the absolute best 4-bbl on the road - yesterday and today. Yours is probably the 850 cfm model with vacuum secondary air doors. DO NOT ever let anyone talk you into using a Holley carb on that engine. You'll spend a slew of money and be very sorry. For parts and carb kits, talk to the guys at www.allcarbs.com. They have built some fierce QJ's for my Olds 455 marine engines.

08-02-12, 02:49 PM
Thanks. Yes it is 500 ci quadrajet carbureted engine

08-02-12, 02:53 PM
OK - this is going to Engines, 500 c.i.

90% of these Seville/Eldorado owners have never even seen a QJ carburetor much less modified/overhauled them.

Get that Doug Roe book !!! Google something like "quadrajet carburetor doug roe book"

08-03-12, 07:38 AM
Fuel filter is found by removing the "Large" fuel inlet nut screwed directly into the carburetor in the front. Once the fuel line is removed first, from the nut, you unscrew the nut and a paper filter with brass/ metal ends will come out along with a spring. If my brain remembers correctly the gm # used to be 5651803. That was a long time ago when I used to rebuild these things.

There is also another version of the filter that is a brass looking color that screws into the carburetor, but I believe that version has the fuel line clamped on it it. It depend how your fuel line mates to the carburetor.

Good luck

08-03-12, 11:06 AM
^^^ Post #3. ^^^

08-06-12, 08:18 PM
Google IMAGES "quadrajet fuel filter" and you will see everything you need.

08-06-12, 11:02 PM
When I replaced fuel filter on my 80 cdv. (368) you need two wrenches, one to remove the actual fuel line, and the other to hold the nut that holds the fuel filter
onto the front of the carb.,just a little tip that you may find helpful.