Chris and Jon,
I believe your trucks are both earlier than my 1954 truck. Before 1954, the fuel tank outlet was on the bottom of the tank and fuel was gravity fed to the pump. On my truck, the fuel feed is at the top (integral with the tank sender) and the pump must pull the fuel up out of the tank. The stock pump is a displacement pump so it will pull the fuel up even if the tank had been run out of gas. (and refilled, of course)
I have a car with an electric pump where the situation is similar to my truck; the pump must pull the fuel out of the tank. If I run the tank out of gas, I have to prime the pump to get it to work again - not something you want to do at the side of the road. This pump is a rotary vane type pump and I believe if it was a different design, it wouldn't need priming.
Question: do you know if the pump you are using work on a 1954 tank? IOW, it's self priming?
I didn’t understand what you were referring to when stated “This pump is a rotary vane type pump”(Yours or the one mentioned previously in this post).
It got me thinking about my 1955 6700 Bus with 327. There is a block off plate where the mechanical pump went and it uses an in-line electric pump. I did some on-line research and found that I too have a rotary-vane style pump. If the truck sits for more than a couple days I have to run pump for several minutes to get fuel to the carb. It ran out of gas once, I just let the pump run for awhile and it eventually primed.
I also read about the Gerator-style pumps. The rotary-vane pumps are good for fluid transfer, create a pulsing pressure, have more moving parts that cause it to run hotter and work with carbed engines. The Gerator-style pumps create more vacuum and steady pressure, good for carbed, and EFI engines.
The Type of pump, Gerator, or Rotary-Vane does not seem to be on the spec list of the pumps that I found on-line. I don’t know if you could tell the difference by looking at the case.
