Rest pressure troubleshooting - Sanity check me

[seventy4burban]

So I have been fighting a rest pressure problem for sometime. When the engine shuts down I loose all rest pressure within a few minutes. I have inspected the system (tank, lines, filter, accumulator, injectors) and have no leaks. I have also just put a new accumulator in it. I have the new DMC pump unit. I got it right after they came out and I recently found out about the initial run have problems with the check valve. So last night I did the following. I hooked up my pressure gauge to read the primary pressure and jumped the RPM relay. I was reading about 70 psi. I put a c-clamp on the hose coming out of the fuel pump and clamped it down just as somebody pulled the jumper to kill the pump. After 10 plus minutes I was still holding about 2 bar of pressure. While watching the gauge I had my helper release the clamp on the fuel pump hose. Pressure instantly begin to drop and was zero within about 30 seconds.

So I'm calling the fuel pump check valve bad. I can think of nothing else save the o-rings in the fuel distributor which I really don't want to mess with. Its not the original fuel distributor so I'd nope its not bad.

What do you guys think? This problem is gotten beyond annoying.

Thanks

[Bitsyncmaster]

I would say that test you did pretty much proves the check valve is bad.

[Jonathan]

I would say that test you did pretty much proves the check valve is bad.

+1

[David T]

+1

And you were able to do it without having to make up a valve and fittings, just a "C" clamp! Yes, that would confirm a check valve that is missing or defective.
David Teitelbaum

[seventy4burban]

All right guys thanks! Guess I'll be talking to Houston come Tuesday.

[Ryan S.]

Your warranty might be over. I think they only cover for 6 months. You can add an external check valve if they won't replace your pump.

[seventy4burban]

I've talked to them before about this. I'm pretty sure they said since its a problem in the first run that if you have a bad check valve they will replace the pump if that turns out to be the problem. It must be pretty wide spread if they have already came out with a second design pump. They been out what like a year or so?

[Ron]

And you were able to do it without having to make up a valve and fittings, just a "C" clamp! Yes, that would confirm a check valve that is missing or defective.
David TeitelbaumNote he didn't put it on the return hose as you suggested in robplus4's thread...