Fuel Pump Rebuild

Posted by Jim Kavanagh On 2017/5/12 14:50:29

I rebuilt the double action fuel pump on my '52 convertible, but I feel I must have done something wrong. When I let off the gas, the engine is rough and wants to stall, this will calm down after a second or two. When this happens, the vacuum goes too high and takes a couple seconds to reduce down to the right level. If I by-pass the pump and connect the two vacuum lines together, everything works fine, the vacuum is exactly was it should be.

I think this may be because I messed up the valves in the vacuum chamber. I used the procedures in the '52 manual because there were no instructions with the pump. In the vacuum side, I put the valve by the casting in with the "spiders" down,I also installed a valve in the hole in the bottom of the vacuum chamber the same way (legs down). The manual does not mention a valve in the hole in the chamber, just to replace the one by the casting. There had been a valve in the chamber when I disassembled it (but I didn't note which way it faced) and the kit came with 6 valves, so i assumed one needed to be there, but it does seem to not allow the vacuum to dissappate quickly enough.

I also note yesterday a small amount of oil leaking from the pump. It looks like the diaphram area, not the attachment to the block. I will tighten a bit.

I Did I assemble this correctly?