57 Fuel pump question

[wearymicrobe]

Really dumb question but it is 11:00 at night and I have been hammering on the Caddi.

Been having some fueling issues on the 1957 CDV. Basically at anything under say 50% throttle car runs fine. About that it falls on its face. Been thinking it was bad gas or the secondary's not kicking in.

Found that the upper gasket on the fuel pump was completely shot. like holes in it on the inside. Made one out of ETOH resistant rubber and reassembled it and seems to be running like a dream now. Is the upper chamber on the 57 fuel pump need to be completely sealed. Used to working on much older stuff where the lower just forces the fuel up and the one way valves are in the same chamber and it is completely sealed.

This is the seal that I made a replacement for, it was venting inside between both the chambers. No leaks outside the pump though. Seal I made is pretty hidious.

[Roger Zimmermann]

At the outlet of the fuel filter, you have 2 fuel lines. I'm assuming one is going to the carb; where is going the other one? I suppose your car is equipped with A/C and there is a vapor return line. Unfortunately for you, the fuel filter you have is not for this application, it's for cars without A/C.
With your set-up, it's no wonder than you cannot have full power, about 50% of the fuel is going back to the tank if my assumption is right...

[DBDB]

I never heard that some 1957 cadillacs had a vapor lock return line .From what year on is this the case ? Thanks

[Roger Zimmermann]

Since 1857 on cars with A/C.

[Walter Youshock]

Cadillac fuel filters are installed opposite the way yours is.  The bowl should be up.  The return line was attached to a fitting on the bottom of the filter body.

[55 CDV Fan 82]

I was going to install mine without a fuel filter once I get mine in around mid April.  Fuel tank and lines are new so I'm not too concerned with particles in my gas.

[Roger Zimmermann]

When the car was new, tank and lines were clean too...You may refuel with dirty fuel, especially if the tank at the refill station is almost empty. I would not take that chance.

To Walter Youshock: you are correct about the position of the bowl. However, this is more logical to have the bowl down: you see if there is dirt and, when you are removing the bowl, the gas stay in...Unless there is a "Z" at the pump outlet, the standard position of the filter is like you explained because the bowl cannot be down due to the limited space.

[wearymicrobe]

That photos is just someone else's installation. Easier then trying to get a photo online at night when you are covered in grease and tired. Mine is OEM and by the book.

Just need to know if the upper chamber requires a air tight seal for my sanity.

[Roger Zimmermann]

Just need to know if the upper chamber requires a air tight seal for my sanity.

Yes, it must. Otherwise, the fuel is not getting to the carb but in the engine compartment.

[55 CDV Fan 82]

Does anyone know if the fuel filter were an item originally installed from the dealer?  There are replacements on the interwebs but it would be cool to see some photo evidence

[Walter Youshock]

Yes.  Fuel filters came installed from the factory.

[Jon S]

Yes.  Fuel filters came installed from the factory.

Correct and the Factory ones were "stone" material; not pleated paper.

[57eldoking]

I think the posted picture is of a dual quad setup. You can see the gold valve cover and I think also two carbs in the background. The T fitting should have been installed infront of the front carb though, not on the filter. It is also installed upside down.

[TJ Hopland]

Bowl up would seem like a really odd orientation for a filter.  Down you would think would be better for sediment and water.   

[57eldoking]

You're right TJ, it does seem counter-intuitive when you think about it. I was a little quick in just trusting my memory on this one. I couldn't recall ever seeing those two 90 degree elbows which are required in order to flip the filter and not have clearance issues. This screenshot is from a 58 instructional video on the new 3x2 carb setup clearly shows the filter upside down. Why would it be different in 57?

The return hose from top of the filter is also very visible on this AC car.

[55 CDV Fan 82]

Cool photo thank you!

[55 CDV Fan 82]

Just curious but what is the size of the threads for the inlet/output tubes for both the pump and the filter?

[57eldoking]

Thinking about it, the posted picture probably is of a 58 3x2 setup! It matches the factory photo with the T-fitting immediately after the filter.

[Jon S]

You're right TJ, it does seem counter-intuitive when you think about it. I was a little quick in just trusting my memory on this one. I couldn't recall ever seeing those two 90 degree elbows which are required in order to flip the filter and not have clearance issues. This screenshot is from a 58 instructional video on the new 3x2 carb setup clearly shows the filter upside down. Why would it be different in 57?

The return hose from top of the filter is also very visible on this AC car.

. . . and look - The Fuel Pump is not painted blue; but rather natural as mine was new from the factory in 1958!

and it is a slant top, as was my original.

[Dan LeBlanc]

What are those I see?  TOWER STYLE HOSE CLAMPS