Fuel line
1. Fuel Tank
The fuel tank serves as the starting point for our fuel system. In these iconic vehicles, the tanks were designed to withstand the rigors of off-road driving in war zones. Made from sturdy metal, these tanks were crucial components, ensuring a constant fuel supply. They are located under the driver's seat and protected by a cover.
For restoration enthusiasts, faithful replacement tanks are available today to maintain the authenticity of your classic Jeep while ensuring a clean and impurity-free fuel system that could cause long-term issues.
Rectangular fuel tank cover (Early) on a Willys MB Slat Grill (ref: WOA3497E)
The early tanks for Willys MB and Ford GPW from Nov. 1941 to Sep. 1942 (serial numbers 100001 to 174738) were angular with a "small cap", which made it more challenging and time-consuming to fill from jerry cans in the heat of battle. This was quickly replaced by a "large cap".
Early pilot seat frame with a round trap door for the "small cap" tank (left)
versus the later version for the "large cap" tank (right)
Furthermore, switching to the "large cap" allowed engineers to add a funnel filter to make it easier for GIs to fill the tank and also to prevent a lot of impurities on the battlefield.
Small cap tank (ref: WOA1221), large cap tank (ref: WOA6618),
as well as the funnel filter (ref: WOA6424)
This also streamlined logistics by standardizing parts because this cap diameter was already used for Dodge and GMC tanks.
2. The Fuel Pump
The fuel pump is responsible for transporting fuel from the tank to the engine. In these vehicles, fuel pumps were typically operated manually.
If you need to replace the fuel pump in your classic Jeep, be sure to choose a high-quality unit to maintain the original performance.
Fuel pump with its priming lever (ref: WOA8323)
This type of fuel pump (known as AC for AC Spark Plug, a division of General Motors) is manually operated using a lever. It consists of an eccentric piece connected to the engine's camshaft and a lever to prime the carburetor's fuel bowl.
(We also offer a repair kit for your fuel pump ref: WOA7834)
Advertisement for AC Spark Plug's fuel pump (post-war with glass dome)
To maintain its proper operation, it's important to regularly clean the filters: in the fuel tank compartment (hopper), the fuel filter cartridge, and also, if necessary, the filter in the fuel pump.
You can do this by using a clean cloth that doesn't shed fibers, moistening it with clean fuel, and using a soft brush if needed to thoroughly clean, then dry everything with compressed air to remove any remaining impurities.
AC mechanical fuel pump / Ford GPW Go-Devil Engine
During the installation or maintenance of this pump, make sure to place a new gasket at the engine block level to prevent oil leaks.
Also, check the attachment of the bowl, which was originally made of metal during World War II and then changed to glass to provide a visual of the priming of the pump.
Once everything is in place, prime the pump by operating the lever, which will fill the fuel bowl.
Finally, carefully inspect all connections once the engine is running to ensure there are no leaks at the joints and fittings.
3. Fuel Filters
Fuel filters play a crucial role in preventing impurities and particles from contaminating the fuel and, as a result, ensuring the proper functioning of the engine. When restoring your classic Jeep, it's important not to overlook these components.
High-quality fuel filters ensure the optimal operation of your vehicle and extend the engine's lifespan.
Fuel filter with its "AC" decal installed on a Willys Jeep MB
Following the same strategy as the fuel tank, the Jeep's fuel filter is identical to that of the Dodge and GMC. This is why it has 2 "IN" and 2 "OUT," although only one side is used.
The difference lies in the presence of "F" and "360" instead of "212" for the Ford GPW version and only "IN" "OUT" "1504" "212" for the Willys MB version.
Fuel filter diagram (left) and the fuel filter housing for Ford GPW (right)
Only the fuel filter housing is painted Olive Drab; the bowl is always a metal color with the decal of the brass filter from the AC Spark Plug Company. This is due to the fact that the company has been a division of General Motors since 1909, as mentioned above.
Brass fuel filter cartridge on the left and cardboard on the right
During cleaning, it's crucial to be careful not to let gasoline spill onto the starter.
Here's how to proceed with ease:
- Start by unscrewing the cover bolt while ensuring not to damage the gasket.
- Once the cover is removed, focus on cleaning the bottom of the bowl, then use compressed air to blow out the filter element.
If your filter is made of paper, it needs to be replaced.
If you have an original brass lamella filter and it's still in good condition, you can also clean it.
- Next, reinstall the filter, using a new gasket if necessary.
- Once this step is completed, start the engine and let it run to check for any leaks.
P.S: A decal is not a sticker; it is applied by dipping the decal in warm water, and as soon as the image detaches from the paper when touched gently, apply it by sliding it onto the slightly moistened surface.
"AC" decal for the fuel filter
4. Fuel Lines
Fuel lines transport fuel from the pump to the engine. They must be in good condition to prevent potential leaks and maintain the necessary pressure. When restoring your Jeep, carefully inspect the fuel lines and connections, and replace them as needed to ensure safe and efficient operation.
Fuel feed line (ref: WOA1366K)
In Conclusion
The fuel line is an essential aspect of Jeep maintenance and restoration. By keeping key components such as the tank, pump, filters, and lines in mind, you can ensure that your classic Jeep continues to run reliably.
Make sure to fuel your Jeep with SP95 or SP98 and avoid E10. Gasoline has lubricating properties that ethanol lacks, as ethanol is much drier and corrosive. It's proven that high levels of ethanol are not suitable for rubber hoses, fuel pump diaphragms, and carburetor accelerator pumps. Moreover, in the long run, it could also damage your engine's valve seats.
Naturally, it's also advisable to choose quality products to preserve the authenticity and performance of your precious vintage Jeep.
