Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: motard on October 04, 2024, 02:11:53 AM

Title: 1974 Eldorado Cadillac Fuel Pump Replacement
Post by: motard on October 04, 2024, 02:11:53 AM
A. On the 1974 Cadillac fuel pump replacement, does the fuel pump lever work directly off the crank shaft?

B. Or does it has a push rod that pushes the fuel pump lever and the push rod works off the crankshaft?

C. If it has a push rod, I need to know if I have to worry about the push rod falling down out of place when you remove the old fuel pump?
Title: Re: 1974 Eldorado Cadillac Fuel Pump Replacement
Post by: The Tassie Devil(le) on October 04, 2024, 02:24:22 AM
The Fuel Pump arm works directly off the Cam Shaft.

It helps in installing by putting the crankshaft on TDC Firing Order for No. 1 Piston.   This way, the eccentric lobe is at its' shallowest point so there is not too much pressure on the arm.

Bruce. >:D
Title: Re: 1974 Eldorado Cadillac Fuel Pump Replacement
Post by: TJ Hopland on October 04, 2024, 11:49:23 AM
I have not had issues getting pumps installed with the engine stopped in random positions.  The bolts tend to be long enough you can get them started at which pint you can either bring it in with the bolts or use your other hand to hold the pump in place while turning the bolts.

The tricky aspect of these tends to be the metal outlet line that goes up to the carb.  Its basically a brake line and people tend to over tighten plus its fairly low so it can pick up road spray.  The nut on the line I think is a 9/16 and you want to have a flare nut wrench, a standard open end tends to just round these off.  Its threaded into a large 'nut' that is the cover for the fuel filter and this is like 1 1/4" range so you need to hold that so it doesn't spin out and twist the line.

If you do damage the line its kinda hard to replace because of how sharp the bend is, regular hose will just kink.  Something like marine grade will work because the walls are extra thick.


The inlet and return lines are just regular 3/8 and 1/4 hose and clamps.  Note that there are also short sections of hose back by the tank that are often ignored and could be causing your issue. Those too are standard hose, same sizes 3/8, 1/4, and a 5/16 vent line.  You don't have to drop the tank the hard lines extend to the edge of the tank.  The RWD cars are more difficult because the differential is kinda in the way but the narrow Eldo rear axle gives you a little more room to work back there. 
Title: Re: 1974 Eldorado Cadillac Fuel Pump Replacement
Post by: Big Fins on October 04, 2024, 04:18:34 PM
They can be done without the engine exactly at TDC, but it's a lot easier when the eccentric isn't at its peak of the pump stroke.

Put a dab of HD wheel bearing grease on the arm section that rides on the cam eccentric. It just helps stop initial wear of the pressure plate on the pump arm.
Title: Re: 1974 Eldorado Cadillac Fuel Pump Replacement
Post by: motard on October 06, 2024, 08:33:06 AM
Guys thanks for the information. I put the engine at TDC and the pump went in very easy. I will check the rubber fuel lines.
Title: Re: 1974 Eldorado Cadillac Fuel Pump Replacement
Post by: Big Fins on October 06, 2024, 09:45:11 AM
Replace the old lines with Gates Barricade Green Shield Fuel Hose. It is rated at 50 psi and it double reinforced which also helps on the suction side of it from collapsing. As noted, you will need 3/8" for the main fuel line, 5/16" for the return and 1/4" for the vapor canister return.

I bought 5' of each which also gives me some extra to keep on hand for other things.