1997 Dodge Ram stalling/did not crank over

Engine Mechanical problem
1997 Dodge Ram V8 Four Wheel Drive Automatic 200.00 miles

i sent in my question on the 13th or the14th. You asked me to check the pcv, changed 1 month ago, clean the i.A.C, I did last week. Now I need to know how to clean the egr valve and how to check the f/p relay, if its just looking at the fuse to see its not broken, well I have done that. Now the last thing to check was the fuel pressure, were do I hook up the gage to check the pressure and what shoud the correct pressure read? What my real question was to you was that I didnt want to change my f/pump and spend 750.00 if I dont have to. What other signs are there if it is the f/pump, I axplained to you before that I did not hear a whinning noise, but I do hear a whinning noise only when I back up the truck. I also explained to you that my truck was stalling for several weeks almost every time that I slowed down, now after the station had cleaned the i.A.C and the t.P.S the truck do not stall any more, but 3 days after that in the morning the truck did not crank over and towed it to the station, he told me he breaflly diagnosed the truck and said most likely it could be the fuel pump, but he was not sure. He then hit the gas tank with a hammer and since then the truck has been starting every time and driving fine for 5 days now. Does this sound anything like a f/pump, should I keep driving until something happens, this is driving me crazy, also my check engin light has never come on. Please help with some input, I will now check the pressure and the a.S.D what ever that is. I have been dealing with this whole thing just after having back surgery 2 weeks ago. Thanks, desperate.