The "lift pump" is actually the engine's fuel pump, providing fuel to the high pressure injector pump. A cam moves the diaphragm when the engine is running. When you use the handle, as long as the cam is not in the high position, you move the diaphragm, but if the cam is in just the wrong place, the diaphragm won't move.
The rubber squeeze bulb solution for bleeding is a life saver. I don't know how I would bleed the primary fuel pump without it. (I have a racor without the built in pump.) Just squeeze until fuel comes out the racor's bleed vent. Then bleed the little filter above the lift pump. Run awhile, bleed the little filter again. When you change the racor filter cartridge, be sure to fill it by hand before attaching it to the mount.
When using the squeeze bulb, you can feel whether there is air downstream. If so, you can do a few squeezes before pressure builds. If not, the thing is hard right away. I always worry about squeezing too much, since the low pressure side of the fuel system (in particular the diaphragm in the lift pump) does not expect much pressure.
Good point about changing the lift pump every couple decades. I will go and do it.
