The Stovebolt Site Forums The Shop Area Engine Shop fuel pump keeps going out

I only get to work on my truck, 54 w/235, every two months or so, sometimes longer. the last two times I have tried to start it after it has sat for a couple of months the fuel pump has had to be replaced even though it was working fine when I left it. I assume the diaphram is drying up and cracking???? any solutions or other posibble causes?

If you are buying new or rebuilt pumps from your FLAPS I'd certainly take them back for exchange. If your truck sat for a long time before you acquired it one possibility is there was old gas in the tank when you put fresh gas in it. What that can do is put varnish from the old gas into suspension in the fresh gas. When you let it sit and things dry out it can turn back into varnish on the small one way valves inside your fuel pump which will cause it to not pump. If that's the case you'll need to drain, remove and clean your tank. That process has been discussed here many times. A search will get you hours of reading.

This truck was a daily driver until about a year ago and I never had this problem. Only after it has been setting. I will take this pump back and try another.

Ed,
Just a thought, but after you get the pump replaced add some STABIL to the tank and some fresh gas an run it a bit ..the stabil should help while it sets around.
STABIL gas treatmeant is cheap insurance in my opinion..i swear by it especially in my Bass Boat & vehicles that are stored in the winter.
Tim

i had an almost new one go out after sitting for 2yrs during a rebuild. i read and article about the new ethanol fuels have a bad effect on diaphragms and rubber. i added an electric as a backup.

yes my dad added a electric pump on demand pump ,to get gas to the carb faster when it Set's a while they mechanical pump's bleed off pressure ,when the check valves go bed .it helps for a faster start up ,easier on the battery also.

I would guess it is the ethanol based fuel. It turns into a greenish white gel in the fuel lines. I will start working on small engines and outboards down here for supplemental income because if you leave the fuel sit for more than 2 months, it will gel. The ethanol doesnt have the carbon backbone to keep from breaking down that true 100% gasoline has.

Same goes for low sulfur diesel. The sulfur provided the carbon backbone to keep the fuel from degrading over a short period of time. long story short, you have to drive it more often or find non ethanol fuel.