I agree with post #2. I seem to remember that the issue is in the valve body, maybe the metal dividing plate and a check valve. I don't think that the issue is related to the front pump. A good tranny man should know about this common problem.
Mine does the same thing, all the parts mentioned are new or replaced. It doesn`t bother me at all. My 'bought new" 2002 dodge quadcab did it too. The factory manual said it was normal , and not to worry. I didn`t worry about it for 15 years, and was still fine when I traded for my 2014 ram.
