Priming mechanical fuel pumps

[rattlenbang]

This is a head's up to anyone replacing a big block fuel pump. The previous owner of my rig (M300, orig. 413, now 440) replaced the fuel pump, but couldn't get it working. I bought the MH, saw no fuel coming out, also replaced the fuel pump, still not working. Frustrated, I purchased an electric pump and everything was good until the electric pump burned. FYI, most aftermarket electric pumps are junk, in various applications I've gone through several.

I pulled the tired 413 and installed a 440, with it's own fuel pump still attached. No fuel. Extremely frustrated, now I pulled the 440's old pump and installed the new mechanical pump I had tried on the 413 (they're the same pump). Still no go. 

Long story short, unlike modern pumps, it seems you have to prime these pumps if you end up with a drained fuel system, which can happen when you replace a filter or do any work on the fuel system. What I did was use a manual collector pump (that I use on my boat to suck up oil through the dipstick tube during an oil change), and attached it to the fuel line at the carb. Pumping away I was able to draw fuel from the tank all the way through the fuel system. The truck started instantly.

Nobody I spoke with had heard about this, and there's actually precious little on the internet. But without a doubt, none of the mechanical pumps worked without priming. I wated a lot of time rediscovering this old knowledge.

[Stripe]

Good info to know..
Thanx