Fuel Pump Gaskets

slats · Post by **slats** » Thu Jan 08, 2015 2:56 pm

Gentlemen,

I have heard that the current unleaded gasoline we use will eat away at the original fuel pump gaskets. Has anyone else heard this? Just as an FYI I have a 1953 M38A1 with the original fuel pump with approx. 7,000 miles of gas run through it and I have had no problems - yet.

Please let me know your thoughts,

Jesse

BB · Post by BB » Thu Jan 08, 2015 10:18 pm

Yes the ethanol in todays fuel is not friendly with older rubber products and can be also hard on metal parts like tank sending units. I buy fuel for my M38 at a station that is across from a boat ramp and sells non ethanol fuel for lawn equipment, recreational and antique vehicles as it is not legal for regular vehicle sales. It is more expensive but causes less problems. Use it in mowers an gas trimmers too fuel lines and primer balls last a lot longer.
Brian B Dunedin, Fl.

Post by **wesk** » Thu Jan 08, 2015 10:27 pm

Rubber parts produced since the 90's will tolerate the ethanol. Ethanol still is a problem since it tends to leave gummy deposits behind that plug things up. All the lead substitute crap is a waste of time. Yes it helps with high compression, high performance engines but has little effect on your 6.48 to 1 L or F 134. What would really help is something that would remove the ethanol from your gas. Since there is nothing available to do that the next best thing is buying gas that does not have ethanol in it. There are some off road pumps products and avgas that do not have ethanol. Try to use them. If you use the 100 LL avgas mix it half and half with your pump non-ethanol or E55 ethanol gas. This will make a marked improvement in both performance and the longevity increase for your gas when you store the jeep over the winter.

AAHUNT · Post by **AAHUNT** » Fri Jan 09, 2015 10:19 am

I was told to use high octane (92-93) in my small engines as it does not have ethanol. However, this is partially true...You have to look at the pump to see if the high octane has any ethanol added. I had to do a little searching but I have found several stations that carry ethanol free good stuff. I also add "Seafoam" brand additive to any gasoline that will see some storage (cheaper and better IMO than sta-bil). "Sta-Bil" brand also makes a specific product for ethanol fuels...never tried it. I can say that my yearly fight with dead and dying weedeaters ended with the above advice.

ChuckW · Post by **ChuckW** » Fri Jan 09, 2015 11:18 am

I've been building mules for the past 10-12 years and I can tell you they absolutely DON'T like ethanol gas. Average life of a fuel pump is 2-3 years, and not much better on the carbs. I try to use only non-ethanol gas, but have found some of the stations around here who claim to have non-ethanol gas really don't. How to tell? Here's an interesting article on how to test for ethanol in gas:
http://www.autofuelstc.com/fuel_testing.phtml

The problem with ethanol is that it's hygroscopic, it likes water. During periods of extended storage, Ethanol tends to draw in atmospheric moisture which can lead to a build-up of water in your fuel tank. Since water is heavier than gas, it will seperate and go to the bottom of the tank. During periods of long storage, this can cause a metal fuel tank to literally rust from the inside out. Bad stuff!