1957/58 Fuel Pumps

[Coupe]

 The fuel pump in my '57 failed on my way to Back to the Fifities in St Paul. My only choice on short notice was an electric. (I know I should have one any way for easier starting after a long time parked.) NAPA and Autozone can get the '58 pump but not the '57. Hollander says they are different pumps. What is the difference between 1957 and 1958 fuel pumps? Kanter lists the same fuel pump for '54 thru '67 all except '57/'58 Broughams.

[Walter Youshock]

The original '57 pump is ONE-YEAR and ONLY Cadillac.  The pulsator diaphragm cover is at an angle where the '58 is horizontal.  Also, if you put a '58 pump on a '57, the original steel line to the carb won't line up.  The screw holes between the pump top and bottom are in a slightly different position than the '57 housing and the line ends up short.

This I do know because I tried it...

[Jon S]

The fuel pump in my '57 failed on my way to Back to the Fifities in St Paul. My only choice on short notice was an electric. (I know I should have one any way for easier starting after a long time parked.) NAPA and Autozone can get the '58 pump but not the '57. Hollander says they are different pumps. What is the difference between 1957 and 1958 fuel pumps? Kanter lists the same fuel pump for '54 thru '67 all except '57/'58 Broughams.

There are two 1957 fuel pumps on ebay now!

[Jon S]

The original '57 pump is ONE-YEAR and ONLY Cadillac.  The pulsator diaphragm cover is at an angle where the '58 is horizontal.  Also, if you put a '58 pump on a '57, the original steel line to the carb won't line up.  The screw holes between the pump top and bottom are in a slightly different position than the '57 housing and the line ends up short.

This I do know because I tried it...

Walter -

Not sure where you get your information - My late production 1958 came with the angled diaphragm cover from the factory and my friends mid production 1958 did likewise.  The replacement fuel pumps from AC were flat top in the late 1950's/early 1960's.

[Walter Youshock]

I can ask you the same question...

[Jon S]

I get my information from my purchased new 1958 Cadillac.  Had it since 8/1958.

[Jon S]

Hope somebody can post a definitive answer as to "slanted" fuel pump for a 58 or not.

 I just restored my 58 Series 62 and I needed a rebuilt fuel pump. Vintage Cadillac in Arizona told me I needed the "slanted" fuel pump to be correct.

 I had to pay an extra core charge because I didn't have the proper "angled" core for the exchange.

 The core that came off my car was an AC replacement that Vintage Cadillac stated is not factory correct for the car as the diaphragm cover on it was horizontal.


 

Can't be any more definitive than what I posted above:

"My late production 1958 came with the angled diaphragm cover from the factory and my friend's mid production 1958 did likewise."

I hope you asked for your flat diaphragm cover with the AC Logo back!

[J. Gomez]

Folks,

Maybe this will help;
The 1946-1958 MPL 22nd edition show Group 12;
1957 fuel pump AC type 4362

The 1946-1958 MPL 23rd edition show Group 12;
1957 fuel pump AC type 4362
1958 fuel pump AC type 4491

The oil filler tube under group 8.2900 shows to be different part # for 1957 and 1958.

The 1955-1964 MPL 29th edition show Group 3;
1957 fuel pump AC type 4362 (casting No. 4479)
1958-1962 fuel pump AC type 6744

http://www.modifiedcadillac.org/documents/Shop_Manuals_and_Illus_Catalogs/Master%20Parts%20List%20thru%201964/Group%203/tn/Group%203%20-%2069.jpg.html

Attached picture is from 1946-1958 MPL 23rd edition show Group 12;.

Hope this helps..!

[Jon S]

Your Fuel Pump.PDF shows the slanted diaphragm for both 1957 and 1958 which confirms my statement.  Very few of us have our cars from new - I do and since mine was a late production one that came with the slanted diaphragm, I think it is safe to conclude the 1958 model year came that way from the factory.  The United Delco replacement 713 was of the flat diaphragm type.  I sold these in the late 1960's.

[Coupe]

Thank-you to all who replied to my post. I've been away from the internet for a few days and could not respond sooner. Per Mr Gomez's pdf I have had the wrong fuel pump since I bought the car in 2001. When I restored it I bought a "new" fuel pump from NAPA and it was identical to the one I replaced.
I guess for now I will go with what's available until I can find an original to rebuild.

[Dave Burke]

Be careful when looking for a rebuild kit - I still have my original pump from my '57 and I ordered a set that had a pulsator diaphragm that was too small.  I ended up going to a new pump that works fine even though it is not entirely correct.

Good luck - fuel pumps is tons of fun!

Dave Burke