Mechanical fuel pump failures


http://209.208.111.198/Topic75083.aspx 		Print Topic | Close Window

By y not - 13 Years Ago
I have replaced the fuel pump on my 1955 f-250 at least 3 times, maybe 4. The pump will work great when brand new, then it will start hard and finally fail completely. I doubt I have put more than 500 to 600 miles on any of them. I run 91 octane fuel which does not contain ethanonl (the gas pump does not have an ethanol disclaimer on it so I assume it is ethanol free). I have used fuel pumps with the fuel filter built in and ones without. I use the original fuel filter with the glass bowl and pleated filter inside when the pump does not have the filter built in. I believe this should eliminate any possibility of contaminants from the tank causing the failure. Has anyone else experienced this kind of trouble? Are aftermarket pumps that poorly made or am I overlooking something?

Thank you.

By speedpro56 - 13 Years Ago
Try the ones for 390 FEs and see if that helps. I'm using the ones made by holley and they work fine but not cheap.
By stuey - 13 Years Ago
hi YNOT

i have zero experience of fuel pumps but i am in the market for one so have been searching the net.

they range from $30 to $300.  i guess you get what you pay for. for a long time i was drawn to Edelbrock 1724??

but i think i'll go for Carter m6905 about $100.  the $30 ones on e-pay are tempting they even look good but if it is too good to be true it probably is.

stu

By Ted - 13 Years Ago

You might look at the fuel line from the fuel tank to the fuel pump in detail.  If it has a natural trap where sediment from the tank can get trapped, then this can cause the mechanical fuel pump to prematurely fail in that it’s trying to pull against a stopped up or very restricted line.  Those particular line stoppages are tricky in that by the time another fuel pump is put on, the sediment in the line has shifted just enough to make it appear that the new pump is functioning okay.  I had something similar happen on a '68 Cougar and it took several fuel pumps and awhile to figure out exactly what was going on.  Once I replaced that section of fuel line that was full of sediment, no further problems.

By Daniel Jessup - 13 Years Ago
I have rebuilt of a few of the original style double action pumps and have always used new neoprene diaphragms and new valves that contain good rubber seals in them. There are still quite a few of the "new" fuel pumps being sold over the counter that do not have good diaphragms and parts to handle modern fuel. Ethanol is always a big concern, but there are other additives to contend with too.

Can't remember right off hand, but there are only a couple of suppliers for those neoprene diaphragms... those old fuel pumps aren't too hard to take apart and put back together. You would be surprised what you could do.

By Canadian Hot Rodder - 13 Years Ago
I have to agree that they are getting cheaper! I run a Holley mechanical fuel pump (one listed for a 390). The one I had failed instantly on a road trip when the spring under the pump arm disappeared? I assume that it is laying in the bottom of my oil pan! This pump was only about two seasons old and cost me $175.00. Interesting enough, when I went to replace it, Holley discontinued the original part # and it was listed under another #????? Wonder if Holley had a defect with these pumps?
By pegleg - 13 Years Ago
Remember Holley was discontinued for a while. Then bought out. Maybe that's part of the reason. Back 5-10 years ago they really had some quality problems, which do seem to be better under the new ownership.