Thanks guys for the assistance. How much vac should I see when testing?

I saw a thread where it talked about needing to make a board jig to take the pump apart. Is that right?

I also read threads that said it was the check valve on top of the pump that was the main cause of failure. Is that an all or nothing type of failure??

Whunter... it's the last name not first....MCM

Have a great day too.

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1984 300 SD, 2 tank WVO
1996 Ram Cummins, 2 tank WVO,
2004.5 Ram Cummins, 2 tank WVO