What about the oil pump? Was it new, rebuilt or did you use the old one? This month marks 50 years ago that I bought my first semi and I now run over a dozen. I have had to diagnose a lot of strange things over the years. I don't think I ever had a mechanical failure that i couldn't figure out what caused it. If it was new or rebuilt, I would begin suspect new defective. There were always some new defective parts but they are becoming more and more common. Probably less than a month ago we replaced a Cummins ISM water pump just because we saw a little oil at the weep hole at a 15,000 service. The new pump went less than a thousand miles and we had to have it towed. Years ago Cummins paid for the part as well as progressive damage. Now I had to argue to get a replacement water pump. It was a Cummins Recon which is supposed to be rebuilt. However, it turned out to be brand new fresh out of China. And it cost me 6 hours shop labor and a $700 tow. I am very anxious to see how this thing unfolds.
