I've got a 98 silverado k2500 that I put a new fuel pump in. I had fuel pressure and drove it 15 miles with no problem, even at what. Now the pump makes it hum noise, but it has no fuel pressure. I undone the line about 2 feet from pump and turn key on, but no fuel comes out. I've done electrical test and that is correct. I took pump out of tank and I can feel it hum, but no fuel is pumping out line.

Where did you get the replacement pump from? Are you sure you have everything reconnected exactly as it came apart?

I took pump pump assembly apart and fuel was pumping out pressure relief port. Tried to blow air back through line into pump but no air would go back through pump motor. L tried to blow air back through pressure relief opening and air would go out lower filter. I reversed wires and pump would pump fuel back out lower filter. So something was wrong where the line split going to fuel line towards engine and the relief port opening

So I took it back to advance auto and got my money back and ordered one from napa

I tend to shy away from the Auto Zone/Advance Auto Parts for that very reason.

I have the same problem, new pump, hums, but no fuel pressure. So, I returned it for a different brand pump (Walbro) and installed that one. Pump no.2 did the same thing. It worked properly for about an hour, then the car sputtered and ran rough like it was running out of gas, I made it home. I ran a wire directly from my battery to the pump and it hums, but has no pressure or gas coming out of the line going to engine. Its not the pumps, it's the car. I can't figure what would produce this condition. PLease help! I have already dumped thousands into this '97 saab 900.

Do you also change the fuel filter when you change the pump? If the filter is clogged, it may pass fuel for short time until the increased pressure from the new pump pushes what is ever clogging the pump in so tight, the pump burns up. Change the inline filters that are locate somewhere in the fuel line. ON the Silverado, it's inside the frame rail under the driver's side door. It's a cheap fix and was probably the problem in the first place.