double action fuel pump for 1956

[Hillbillycat]

It strayed from fuel to vacuum almost from the start. I wanted to know if I could install a double action fuel pump instead of the single action as an easy fix for my non-working booster vacuum pump.
Thanks for the pics. Any idea on the material of the vanes or dimensions in case they need to be fabbed?

That pump looks so simple with so little parts. Can´t believe it´s so hard to restore.

[Roger Zimmermann]

Probably it's because the outer case is pot metal (or cast aluminum). When there is too much wear, the sealing is no more good and nobody do care because wipers are not always needed and the costs to let repair that pump too high. I let repair mines with an inserted tube. I have 20" vacuum. Even with that, when I push the right pedal, wipers are not especially happy!
The blades are probably still good on your vacuum pump; you may just have to remove the scratches with a file at the sealing surface.

[Hillbillycat]

Hey Roger,
tell me more about that "inserted tube" thing.

Yes, I try to avoid needing wipers but somehow I fail :-) And it really sucks if you drive into rain and have no wipers in heavy traffic. That´s why I want mine to work properly. Still not at the point to convert to electric, though.

[Roger Zimmermann]

tell me more about that "inserted tube" thing.

As it was done long ago, I don't have details. Basically, the mechanical shop increased the inside diameter from the body and pressed into it a steel insert. The inside diameter from the insert was calculated to have a minimum play between the insert and the hub containing the blades. If that play is too generous, the efficiency of the vacuum pump is decreasing. Unfortunately, I don't remember it. 0.1, 0.2 mm? Cannot tell anymore.

[Hillbillycat]

Thanks Roger, I´ll keep that in mind. I´ll have to recheck my vacuum readings on the booster pump and on the wiper motor and post here. Maybe someone has a clue which part is the weak yb these readings.