As I understand it Dodge supplied the lift pump. and this was against Bosches wishes as far as quality goes.

And my point is missed or distorted on the pressure issue.

We are not talking about any system other than the fuel system on the 98.5 to 2002 dodge/cummins.
If the system is left intack/ unmodified workings, if the pressure drops, so does voluume. No if and or buts here.
customers were installing fuel pressure guages and finding below spec bosch standards, and wanting to protect thier expensive injection pumps by asking for replacement of the lift pump.

dodge got tired of changing out weak lift pumps , then started telling customers it was volume that is important. YES THEY WERE RIGHT!!!
But if Bosch says 8-10 PSI is needed to get that volume, that is thier specs on it.
Some dealers tried to tell customers that they could have the needed volume with ZERO pressure!!!

IMPOSSIBLE!!!!

Also, the spec was including enough VOLUME to lube and cool the pump, not just supply the fuel required to make HP.

I wonder if the being able to get the proper volume (with no pressure) might have been a little mis-understood. If the line from the pump was open to run the volume test, as in aiming the line into a container to measure the volume, the pressure gauge would probably read zero, since the line shouldnt be a restriction. You could have your volume with no "indicated" pressure. I would rather see a sized restriction put onto the end of the line and you need "X" volume in a given time and still hold a minimum pressure, say 10PSI.

Once again, you are not dealing with an apples to apples comparison!!
You just described an open system, not closed like bosch specs. ( on a diesel, you don't open a fuel line unless absolutely neccessary)
This is why pressure is the spec!!

Try this if you don't understand.
Do try to fill your swimming pool with the garden hose. Rather that walk to the pool, cut a slit in the hose at the valve to check volume. What happens? The system is open and pressure drops. You cannot check a pumps capacity without a pressure and volume spec!!!

I said : "I would rather see a sized restriction put onto the end of the line and you need "X" volume in a given time and still hold a minimum pressure, say 10PSI."

You said: "You cannot check a pumps capacity without a pressure and volume spec!!!"

I'm not sure why you can't see I just said the same thing - it takes pressure and volume to figure capacity. I was questioning how some people are getting their results, not how the results are figured.

You said : ( on a diesel, you don't open a fuel line unless absolutely neccessary)

Yep, agreed. but how else do you verify actual fuel delivery, a Magic 8 ball? Well, first, how do you install an accurate gauge system without opening lines? Then the only accurate way I know to verify fuel flow to the injector pump is to remove the line from the lift pump and test it there. I'm not looking at Bosches test, but if it doesn't require both a pressure and volume minimum, it's worthless. If it does - GOOD FOR THEM, My point has always been a simple pressure test may be flawed due to a damaged (pinched) line, or operator installed incorrect fittings.

You said : "Bosch didn't spec the volume!! Because it is tougher to do in a closed system. So, they use thier calculations and used pressure."

That may be fine, but why not just do an accurate test and see how much fuel is actually being delivered.

And I'm only talking about this, since you brought it up : "Do try to fill your swimming pool with the garden hose. Rather that walk to the pool, cut a slit in the hose at the valve to check volume. What happens? The system is open and pressure drops." No argument there. Go a step further - take a 100' hose, run water through it with the end open. Take pressure measurements along the length of the hose. I bet they are higher at the supply end and gradually get lower as you get to the open end.

Another point - if Dodge and Bosch was so flippin smart - why didn't they put the lift pump in the rear of the truck, where it would be more effecient and not have engine heat?

At this point we're just snipe hunting and beating it to death. Anybody that doesn't understand the concept of needing more than just a pressure reading to accurately measure total flow, read a book. And that's just a general statement; not directed at any one person.