1970s 1976 Fuel Pump

[cadillac91]

1976 Cadillac 500 engine:  I seem to go through a lot of fuel pumps.  Original one lasted 95,000 miles.  First Carter replacement lasted 4,000 miles.  Second Carter replacement lasted 5,000 miles.  Both were made in China.  Both quit while I was driving 45 mph and left me stranded on the road.  Neither of them leaked.  Is anyone else experiencing this problem?  Is there a better quality pump available?  Thanks!

[TJ Hopland]

A few years ago I thought I was having a pump issue with my 500 and over about a year span tried 3 different pumps from 3 different brands and all 3 of them were identical in every way other than the box they came in.  I no longer remember the brands but I would guess Carter, Airtex, and Delphi. Turns out my issue wasn't the pump but they didn't scream quality. 

Do you know what is failing?  If they are not leaking presumably its a valve failure?   Do you have any sort of pre filter or know if your sock filter is still in place?   I'm just wondering if maybe you are sucking up some crap that is getting stuck in a valve in the pump?  I'm not saying that they are not just junk but that does seem like a really short life.   How many years was that 4000 and 5000 miles?

 

[NickD]

Not sure if this means anything but here is my fuel pump story. I talked briefly about fuel pumps in my post above. Let me tell you the fuel pump story. It is my opinion that the Airtex 41204 pump is not the right pump for this engine. I was not comfortable with the Airtex pump, so I did not try to install it. The configuration of the pump arm was different from the original pump and the diameter of the pump body was also different everything else was identical to both pumps (see pictures for pump comparisons. Please disregard the measurements on the ruler as they mean nothing to the comparison). With that said I bought a Carter M6952 fuel pump. Both pumps (Airtex and Carter) had part identification numbers on them. The Carter was clear and easy to find. The Airtex was hidden and hardly visible without magnification. I Carter M6952 pump, which other than the metal plate riveted to the pump arm is identical to my original pump. I called Carter technical services, and the gentleman told me that they eliminated the metal plate because they went to a hardened steel arm. If you are unable to see the pictures go to "1979 425 engine, wont stay running" page 2. My last update to this post was August 6th or 7th.

* my pump_airtex 4120_1.JPG
111.94 KB, 640x480
viewed 6 times

* my pump_airtex 4120_2.JPG
115.6 KB, 640x480
viewed 6 times

* my pump_airtex 4120_3.JPG
111.77 KB, 640x480
viewed 5 times

* my pump_carter 6952M_1.JPG
107.33 KB, 640x480
viewed 8 times

* my pump_carter 6952M_2.JPG
100.68 KB, 480x640
viewed 4 times

* my pump_carter 6952M_3.JPG
104.97 KB, 640x480
viewed 7 times

[NickD]

my pump pictures. blue pump is original pump. gold pump is airtex. silver pump is carter

[TJ Hopland]

Nick's pump is the 77-80 style.  Will (at least in the olden days) bolt up and probably perform fine in place of the 71-76 pump but they are different as far as the lines and the 71-76 has an internal filter.  The earlier one had 5/16 outlet but it doesn't seem like anyone makes that one anymore, they just seem to sell you the later 3/8 line version an let you figure out how to make it work.