Preventing stale gas

1950 - 1952, M38, questions, discussions, regarding anything related to the M38.
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Re: Preventing stale gas

Post by Joe Gopan » Tue Apr 03, 2018 3:34 pm

I have had to change two NOS CCKW 6 Valve fuel pumps a year apart due to the valves in the pump sticking over the winter which caused failure to draw fuel. The NOS 539S Carburetor on my MB gummed up over the winter two years ago due to the E-10 fuel and refused to run correctly. I installed a NOS 636 temporarily.
Bad stuff, this alcohol laced fuel. My M-37 has had two NOS fuel pumps fail for what I am guessing is the same reason. I installed a 24 Volt pump inline temporarily in the M-37 to get it by.
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Re: Preventing stale gas

Post by W. Winget » Wed Apr 04, 2018 5:01 am

Through practice, (after several hits and attempts with ether fail...) I find if I pull a vacuum at the carb fuel line connection to the fuel pump, I can unlock the crap the Ethanol binds up my WC fuel pump within a matter of seconds without fuel pump removal or replacement. Simply install the hand pump Cone adapter into the open line, pump a few times till the fuel finally moves through the pump, and if really good, turn the hose around and push that fuel into the carb bowl to help prime the carb for initial starting.
V/R W. Winget
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Re: Preventing stale gas

Post by W. Winget » Wed Apr 04, 2018 5:07 am

And adding fuel line dryer (alcohol or methyl alcohol) which you see for sale makes zero sense, it can actually increase the gas to alcohol level sufficiently to make it phase separate into two mixes in the tank, with the water/alcohol mix in the bottom and the gas floating on top. So why add alcohol to an ethanol based fuel? Because they still want to sell the cheap product line to those that think it will fix their cars and clean the engines out....already done by the ethanol...
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Re: Preventing stale gas

Post by Joe Gopan » Wed Apr 04, 2018 5:16 am

Lucas has no Alcohol content.
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HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
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Re: Preventing stale gas

Post by Joe Gopan » Wed Apr 04, 2018 5:20 am

Not familiar with the hand pump you mentioned.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
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Re: Preventing stale gas

Post by W. Winget » Wed Apr 04, 2018 7:22 am

Brake Bleeder Kit or "Mityvac" are common names. On these you can move the connections around to suck or blow, and the reservoir before the tool can catch gas or brake fluid to prevent it from entering the hand pump. It's a must have mechanics tool, especially if you work alone. The one shown below does not have the release button which I know the Mityvac has, (or it's clones) but it may be on the reverse of the gauge. And as I've found, usually the pump pull pin on the handle is a weak point (all brands) which fails at an in-opportune moment, but can be watched.
V/R W. Winget
Here's cheap old Harbor freight "Pittsburgh" brand:
https://www.harborfreight.com/Brake-Ble ... 69328.html
Image
And the REAL Mityvac:
Image

And their info:http://mityvac.com/pages/products_hvpo.asp#
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Re: Preventing stale gas

Post by Wolfman » Wed Apr 04, 2018 7:22 am

I like Raymond's approach. A full tank for long term storage is how I do it. Fuel stabilizers can't hurt but putting a stabalizer in a half full or less tank is asking a lot of the stabalizer.
Locally, in my AO, we have ethynol free gas. That is even better. Cost more.
Length of storage also comes into play. 3 to 4 months, reasonable. 6 months, pushing it. After that, it is a toss of the dice. At that point, drain the system would be advisable.
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Re: Preventing stale gas

Post by Joe Gopan » Wed Apr 04, 2018 9:59 am

W. Winget wrote:
Wed Apr 04, 2018 5:01 am
Through practice, (after several hits and attempts with ether fail...) I find if I pull a vacuum at the carb fuel line connection to the fuel pump, I can unlock the crap the Ethanol binds up my WC fuel pump within a matter of seconds without fuel pump removal or replacement. Simply install the hand pump Cone adapter into the open line, pump a few times till the fuel finally moves through the pump, and if really good, turn the hose around and push that fuel into the carb bowl to help prime the carb for initial starting.
V/R W. Winget
Thanks for the information on the pump, It's worth the try. Stale E-10 fuel symptoms are more severe some years than others. What was consistent Were two NOS M-37 and CCKW pumps at the same time two years in a row. Never had fuel pumps have this type failure in the many many years I have worked on or driven the type. I bought a Mity Vac Test Kit. :wink:
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

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Re: Preventing stale gas

Post by JMZ421 » Fri Dec 28, 2018 2:08 pm

Today I stopped at a local station and picked up 5 gallons of 90 octane ethonal free gas $2.79 a gallon. Not bad, 79 cents more than regular 87 here in Ohio. It seems to work for me over the winter as the M38 sits and runs ok come Spring time. I try to start once a week and the battery tender keeps the batteries in good shape. Thanks for all the help and have a great new year. John

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Re: Preventing stale gas

Post by Joe Gopan » Fri Dec 28, 2018 2:29 pm

Am using Ethanol Free gas in all my MV's. Started using it around August, no more fuel issues,guaranteed. In adition to Ethanol Free, an fuel conditioner by Lucas ia also used.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

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Re: Preventing stale gas

Post by dpcd67 » Sat Dec 29, 2018 10:45 am

Yep, my M37 is not running well now and the only thing it can be is old gas; I try to put only non ethanol in my vehicles but in the M37 I know it is just 10 percent stuff. Too cold now to drain it.
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Re: Preventing stale gas

Post by Mark Jesic » Sat Dec 29, 2018 12:18 pm

Im envious what you American guys pay for a gallon of fuel. Over here we pay more than double that. :mrgreen:

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Re: Preventing stale gas

Post by dpcd67 » Sun Dec 30, 2018 11:46 am

Gassed up my Jeep Renegade yesterday; $1.84. A gallon. Cheaper than water.
So what if you have ten gallons of rotten gas; just throw it away. I do feel sorry for guys in England and Europe.
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Re: Preventing stale gas

Post by Joe Gopan » Thu Jan 03, 2019 2:17 am

I drain the E-10 into a GI Can and use it in my lawn mower. Non Ethanol is the rule for my Gasser MV's.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

Mark Jesic
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Re: Preventing stale gas

Post by Mark Jesic » Thu Jan 03, 2019 3:26 am

So how long is it before we class gas as stale ?


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