Imperial Car Club Forum

Anyone know the part number for the fuel pump used on a 57 Imp?

Based on the 1957 service manual, the fuel pump part number is a Carter M2503S. I believe the M represents a threaded intake, and the S represents a glass fuel filter bowl. It looks like the Windsor (C-75-1), Saratoga (C-75-2), New Yorker (C-76), and all Imperials (IM-1-2-4) used this fuel filter.

I just took the filter off my car and here's what it looks like. It does not appear to be a Carter, so I'm assuming it has been replaced at some point.

So after a little more looking around, it looks like I have an AC branded fuel pump. The AC brand, and other brands modeled after the AC brand, use 10 screws to hold them together. The Carter brand only uses 8 screws from what I can determine.

I'm not sure why the Carter branded fuel pumps are so hard to track down, but it's near impossible to find an exact match for the Imperial. So looks like I'll be sticking with the AC brand and rebuild it. I was able to find a rebuild kit for the 10 screw style, but not for the 8 scree Carter brand.. so even the rebuild kits are rare for Carter.

I'll let you know how the rebuild goes after the kit gets here...

The fuel pump rebuild is not going well. It all seems pretty straight forward, but after I get it back together, I cannot work the pump arm at all. It is frozen in place. If I loosen the screws around the top of the carb, I can work the pump arm with a lot of force, but the moment I tighten the screws back down it won't budge no matter how much force I put on it.

I would love to try a modern mechanical pump, but I can't find any that fit this 392 engine.

Are you sure you should be able to work it by hand at all Adam? I’ve rarely been able to operate a mechanical pump by hand without putting a good portion of my body weight behind it.
I would have added my .02 on the mailing list but my Apple devices won’t even allow me to participate.

Matt, I'm not sure how much weight/pressure it takes for a fuel pump, oddly enough, have never worked on one before. This is my first rebuild.

The odd thing is, I can work it when I loosen the screws, but the tighter I get the screws the harder it gets to function until I can't operate it anymore.

It doesn't seem to affect clearance of the pump, I can still move the arm just as much, but it just becomes more difficult.

Adam, Did you get your Fuel pump issue resolved ?

No, it's still on the bench currently. I got distracted by a few other projects, but order a spacer to use a cheap small block pump just in case I need to fall back on that. If I can get the rebuilt pump functioning correctly I'll use it, but I'm starting to have my doubts.

Someone suggested I take it apart and remove the large diaphragm spring and see if the arm will travel when put back together without that spring, so I'm going to give that a shot and see how it goes.

Mine is an early production model sold new in Jan 1957 with single headlights, the fuel pump itself on mine does not have a filter, the filter is attached to the carb. The filter is a Carter but cannot read the part number

Thanks for the pictures, looks just like mine with the filter at the carb, but mine has that after-market fuel pump which also had another bowl filter. I don't think I need both, so would be happy to go back to a stock Carter pump if I run across one in the future.