FUEL TANK MAINTENANCE

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
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Ben Dover
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FUEL TANK MAINTENANCE

Post by Ben Dover » Mon Jan 07, 2019 10:19 pm

It's a good idea to perodically remove your Jeep fuel tanks every so often to remove the grit, gravel, leaves, pine needles, etc. that sometimes accumulate under the fuel tank. The debris that gathers can draw moisture or cause rust and pinholes to your expensive fuel tank. How often? It depends on how you use your Jeeps.
It was practiced in Army motorpools and any rust or bare spots were cleaned and spot painted.
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
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Re: FUEL TANK MAINTENANCE

Post by GSS » Tue Jan 08, 2019 4:59 am

I bought a Willys once where the carb had to be cleaned twice during the first month.......it had multiple tiny “PTC xx-xx” painted in yellow on the dash next to the glovebox. Finally dawned upon me 6 months after I washed fine sand out of the gas tank that these were quarterly “petrol tank cleaned” dates. Turned out that it had been in service in the Thar desert.
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1942 MB 113037, "Slat Grill"
1945 MB 431740, 20698289-S

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Re: FUEL TANK MAINTENANCE

Post by tsmgguy » Wed Jan 09, 2019 11:06 am

When shining a bright light into the interior of my fuel tank things look bright and clean. There was a surprising amount of dirt and grit in my fuel filter bowl when I serviced it recently, replacing the gaskets at the same time. All of that crud could only have come from the fuel tank. I've been buying fuel at the same station for a number of years. It's my guess that the fuel hasn't always been clean. Can't figure out what to do about this situation, other than to buy elsewhere (where things might not be any better) or service the fuel filter at least annually. Hopefully, the worst of the crud is being deposited into the bowl.
Willys MB 236426, Hood 20336549, DOD 5-20-43
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Re: FUEL TANK MAINTENANCE

Post by dinof » Wed Jan 09, 2019 1:02 pm

Well it appears that if your tank is clean AND the strainer is doing its job then service it as you have done. Have you checked your fuel pump strainer to see if nothing is there? You can even check your carb bowl to see what's going on there. If that much dirt was in the strainer and the jeep runs fine it sounds like you know what to do.

PM is something that good mechanics practice.
Dino Falabrino
On the "G" since 1998.
1943 GPW 102310 DOD 3-3-43

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Re: FUEL TANK MAINTENANCE

Post by Wolfman » Thu Jan 10, 2019 8:11 am

??? Think B.D. was referring to the crud that accumulates in the fuel tank well. Not in the tank.
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Ben Dover
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Re: FUEL TANK MAINTENANCE

Post by Ben Dover » Thu Jan 10, 2019 8:20 am

Mike, you are correct, and the Jeep tanks that suffer the worst seem to be the CJ-2A thru CJ-5 anf M-38 where the tanks rest flat on the floor, MB amd M-38A1 have a similar problem.

Good maintenance technique would find the drivers detailed to the motor pools and cleaning steering knuckles, painting battery boxes or cleaning the crud from under Jeep fuel tanks.
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
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Chuck Lutz
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Re: FUEL TANK MAINTENANCE

Post by Chuck Lutz » Thu Jan 10, 2019 11:58 am

My GPW-17963 came to me with full knowledge that the roof on the garage where the PO kept it had collapsed and a whole winters supply of leaves had fallen into the jeep years ago. While he had swept up the visible ones, there was a LOT of them left when I removed the patched tank that didn't quite seal in some fuel vapors. In addition, the usual holes in the side of the tub where the tool indents are were plainly visible when I bought it.

Rather than try to remove the copper plate that was soldered to the leaky tank, I got one of Peter's tanks from Australia which was made from terne coated steel. That tank interior looks as clean as the day it was put in there.

Interestingly enough, the tankwell has ONE tiny pin-hole in it and is structurally sound so I fixed the hole, cleaned and painted the interior and installed the new tank with Ron's cushions attached to it. So far, after 17 years I have had no problems as I have removed the caps on the tankwell and blown high pressure air in there to remove any debris from time to time.

Joel is correct though....if you get a new-to-you jeep, not only should you probably remove it to clean and repaint the tankwell, but to flush out the tank itself from any debris that might be small enough to get into the fuel system....you don't know if the PO ever did that or if he used a jerry-can to fill it and if that jerry-can had rust or debris that went into the gas tank when filling.

You start a new purchase doing that kind of stuff along with cleaning out the furl strainer and checking the mesh strainer in the fuel pump for a buildup of crud that might impede fuel delivery.

Joel is big on PREVENTATIVE MAINTENANCE and the advice on the fuel tank falls neatly into that approach along with most of the "systems" on the vehicle. No different than buying any older used vehicle.
Chuck Lutz

GPW 17963 4/24/42 Chester, PA. USA 20113473 (USA est./Tom W.)
GPW 108552 4/17/43 Louisville, KY. USA 20371278 (DOD est./Tom W.)
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Re: FUEL TANK MAINTENANCE

Post by OldPappy » Thu Jan 10, 2019 1:08 pm

I have found all sorts of things under the tanks of the Jeeps I have owned.

When I pulled the tank on the CJ2A I am using for parts I found two rusty pocket knives, two fuel caps, 8 22 long rifle cartridges, 3 30-06 cartridges, 67 cents in change, various paper garbage, a handful of rusty nails, gravel, dirt, leaves, and twigs. The remarkable thing was the floor under the tank was still sound though rusty on the surface.

So, yes occasionally cleaning, and touching up the paint under the tank is good maintenance, and also good to clean and touch up the rest of the floor pan from time to time as paint gets worn off in high traffic areas.
A.C.Fults
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Re: FUEL TANK MAINTENANCE

Post by dinof » Thu Jan 10, 2019 2:50 pm

Wolfman wrote:
Thu Jan 10, 2019 8:11 am
??? Think B.D. was referring to the crud that accumulates in the fuel tank well. Not in the tank.
I was answering Tsmgguy's post.
Dino Falabrino
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Re: FUEL TANK MAINTENANCE

Post by signsup » Thu Jan 10, 2019 4:09 pm

What I don't understand is, when I remove my tank, about once a year, I usually find several nuts, washers, lock washer, screws, star washers, etc. I can NEVER find out where they came from. It's like they multiply in a dark garage.

Don't know if keeping the sump caps on or off help or hurts the debris situation, but I presume keeping the caps off would allow fresh air to blow under the tank and keep it drier than with one or both of the caps in place.
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Chuck Lutz
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Re: FUEL TANK MAINTENANCE

Post by Chuck Lutz » Thu Jan 10, 2019 4:11 pm

I roll with the front tankwell cap ON and the rear one OFF.
Chuck Lutz

GPW 17963 4/24/42 Chester, PA. USA 20113473 (USA est./Tom W.)
GPW 108552 4/17/43 Louisville, KY. USA 20371278 (DOD est./Tom W.)
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Re: FUEL TANK MAINTENANCE

Post by Klaas » Fri Jan 11, 2019 12:31 am

Chuck Lutz wrote:
Thu Jan 10, 2019 4:11 pm
I roll with the front tankwell cap ON and the rear one OFF.
So do I, and I have fitted some rubber seals around the top of the tank well.
They are available in a set of four shaped rubbers and a rubber donut which goes around the fuel line.
That will keep out all kind of debris.
Klaas
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Re: FUEL TANK MAINTENANCE

Post by Ben Dover » Fri Jan 11, 2019 6:35 am

The fuel tank maintence is routine in the Army. I enjoy practicing Army PM as it is not only good for the MV, but for me also.
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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