Re: Idiot's First Packard: 51' 200 Ultramatic Coupe

Posted by DavidPackard On 2024/6/14 23:01:27

Chocobo9x

It is a traditional mechanical fuel pump design. Cam mounted eccentric moves an arm, which deflects a diaphragm up and down. A set of inlet and outlet check valve allow the diaphragm to draw-in and discharge the fuel. The check valves keep the fuel flowing in the correct direction. Failure points are several, including: 1) Malfunction valves, 2) Ruptured diaphragm, and 3) Inlet air leak . . . likely at the flexible hose just prior to the pump inlet. Those are the typical failure modes of the pump itself. Another less likely would be a worn arm or eccentric.
If the pump is a duplex design the upper section is a vacuum pump to aid in maintaining wind shield wiper vacuum during low engine vacuum conditions. The design is similar to the fuel side in that there is a diaphragm, and check valves.
I think on this site you can find a tutorial on overhauling a fuel pump. That tutorial has plenty of photos that you can acquaint yourself with the inner workings of the fuel pump. See Literature Archive / How-To’s & Tech Tips / How To: Rebuilding a Packard Fuel Pump.

dp