GM-GMC: fuel system at hot operation, paint roller, gas tanks

Question
    I have a 1980 GMC pick-up.  The engine overheated once and gasoline was not delivered to the carburator.  At an automotive service garage the mechanics replaced the fuel pump (they said they did), but they found only small pressure at the end of the fuel hose that connects to the carburator and still no gasoline was being delivered to the carburator.  Then I think they disconnected the fuel line at the gas tanks and they could restore the supply of gasoline.
    If this problem happens to me again, and supposing it is not the fuel pump, What can I do to restore the supply of gasoline to the carburator?
    Sincerely, Andres R.

Answer
Andres,

Copy and paste this URL into your browser: http://198.208.187.182/internet/PartImage.jsp?mfgname=ACDELCO&prodlinecd=43&acpa...

When you open the link, you will see a tilted photo of a fuel tank pickup unit like the one in your truck.  On the left hand side and tilted up (just below the item that looks like a paint roller) is the fuel line inlet "sock."  This "sock" is a mesh filter that is designed to keep larger particles of dirt and rust from entering the fuel system and damaging the fuel pump. (The "paint roller" is the float for the fuel level sending unit)

Over time (and 25 years is more than enough) this "sock" can plug up and restrict fuel flow.  Unless you want to remove the fuel tank, clean it out, and replace the "sock" here is what you can do:

Take the fuel line loose where it jumps from the frame to the fuel pump at the passenger side front of the engine (this is best done with the tank at 1/4 full or less).  Remove the filler cap from the tank and, using a compressed air hose, blow air down the fuel line back to the tank.  The blast of air should blow the "sock" off the inlet or tear a large hole in it.

Then, get an inline filter of clear plastic or metal, sized for your fuel hose, and splice it in before the fuel pump.  The new filter will protect the fuel pump and is much easier to change than the "sock" in the tank.

It is possible that this is what the mechanics who worked on your vehicle accomplished to restore the fuel flow.  But, you need to make sure that the "sock" is not causing problems and to install a new fuel filter right before the fuel pump to protect it.