i have what appears to be a 1937 fuel pump with vacuum section. my problem is that the unit will not pump gas.

when off the engine, and operated by hand, the vacuum section appears to work fine (will produce suction and pressure when felt by hand). there is no similar action or suction or pressure on the fuel side though.

when installed on the car, and slight air pressure applied to the fuel tank spout, fuel will enter the sediment bowl, exit the fuel pump, and appear at the carburater and the engine will run. when the air pressure is removed from the tank, the engine will stop shortly.

it acts like what ever drives the fuel section components is not working or not connected. i have inspected the fuel diaphram and it looks good (has been rebuilt and all components inside are clean and bright) and all the small valves and springs appear to be in good shape and not stuck or frozen.

an after market fuel filter has been added just before the carb and it appears to be passing fuel ok (can suck fuel through the lines, pump and from the fuel tank delivery system.

is it possible that the fuel diaphram linkage is broken or not working properly and are special tools needed to reveal this secion of the pump.

any help or advice appreciated.

Here is an article on fuel/vacuum pumpsa:
http://www.teambuick.com/reference/fuel_vacuum_pump.html

You will notice that there is a possiblility of damage in the linkage.

Pressure in the tank should not push fuel past the tank, at least not easily unless there is a damaged or incorretly installed check valve.

Take it apart and have a look. :thumbsup: If the pump has never worked, maybe you just have to flip the intake check valve.

Good luck

thanks for the infor. and the web site data/instructions. sounds like i have a linkage problem and the fuel diaphram is not being operated.

thanks.
wlong.

Here is an article on fuel/vacuum pumpsa:
http://www.teambuick.com/reference/fuel_vacuum_pump.html

You will notice that there is a possiblility of damage in the linkage.

Pressure in the tank should not push fuel past the tank, at least not easily unless there is a damaged or incorretly installed check valve.

Take it apart and have a look. :thumbsup: If the pump has never worked, maybe you just have to flip the intake check valve.

Good luck

to rcull,

thought you might be interested in the solution. someone had done a rebuild on the pump i bought and had used the wrong diaphram. the stem was too long (about a half inch) that connects to the operating links. once the travel was used up by the vacuum section, there was not enough stroke to operate the fuel section diapham.

i had another pump that came off a later model buick, about a 40's model, and the body for that pump, where the link arms are mounted, was about 1/2 inch taller than the '37 pump. i used the diaphram out of the '37 in the 40's pump and it works fine.

i plan to order a kit for the '37 pump, or send it for reconditioning. i would like to have a '37 vintage pump to match the car. (by the way, you have to mount the 40's model pump up-side-down in order for it to work. thats right, the fuel sediment bowl is upsidedown but i made sure to put the check valves in the proper direction. that was the pump that was on the car when i purchased it. sediment in the bottom of the compartment, which is normally the top, had the check valves clogged and the pump quit supplying fuel).

thanks for your help.

wlong.