Haulin_in_Dixie

Looking at it from the opposite view, I would bet (don't actually know here) that the overflow valve makes the required pressure for the vp44 and if it goes bad or weak, the result and first time you realize there is a problem is when the vp44 goes bad because of not enough fuel.

So the cause of the bad pump is the overflow but by the time you realze that, it is too late for the vp44. I have mentioned before, my commercial vp44 has a larger overflow valve on it. All it is is a regulator to insure a set amount of fuel reaches the pump and the rest bypasses. So replaceing the lift pump would raise the pressures and make it work well again until the pump goes bad.

I also wonder if the higher pressures like I am running (19 pounds) may weaken the spring and cause failure. I don't think so but it is a thought. This also could be a cause of the fuel being drained from the system on overnight sits.

J BODY

https://www.dieseltruckresource.com/...threadid=67628
....Here's the other discussion on this topic Haulin in case you missed it.

Haulin_in_Dixie

Yes I did miss that one but it sort of goes along with what I said in this one. If thye valve is weak or leaking it would take more fuel pressure to keep the vp happy. If it is not important to the engine then why would the commercial engine have a stronger one? Anyway this is all theroy, but it would not be there if it was not needed. Looks like if it were bad it would be accompanied by lower fuel pressure on the inlet.

TRAVIST

In reference to your original question as to the part number of the part, here it is. Dodge part number 5011824AA. Dodge does not call it an overflow valve in thier cataloging which is why most dealers probobly would/could not find it. Dodge calls it a check valve but in reallity it is the overflow valve. They run about $40.00 from the dealer.

Hope this helps.
TRAVIST

JAFAW

Very few overflow valves go bad on vp44. they are not what makes the pressure.
the internal supply pump is a vane pump and on top of the pumpright front corner is the pressure regulator that raises the head pressure maybe this link will help

http://dodgeram.org/tech/dsl/ISB/Vp44.htm