Cummins X15 after treatment issues

[JimT]

(05-06-2024 )Envirotec Wrote:  Unfortunately the answer to every question is NEVER!

In regards to fuel pump, I am looking for someone to test if the pump is actually bad and maybe repair? From what I’ve been told, these newer pumps can’t be tested??

As for the fuel pump, the problem parts are mostly in the pump head. Look up the details on cummins quickserve, but it's 4 bolts to remove the pump head and a few banjo fitting fuel lines. Visually inspect the cam inside the pump body looking for signs of wear, pitting, damage, etc... same as the engine cam. Again, quickserve has steps to checking the pump head for proper function once removed. Basically your checking to make sure the rollers and tappets are not damaged or worn, and the plungers are not stuck. There's detailed instructions on quickserve for testing the plungers and check valve with shop air. It's all pretty simple, anyone can do it. I did mine in a parking lot. Just need a bench vise to hold the pump head in place. Based on years of feedback from owners and shops it's considered a good preventive measure to replace the rollers, tappets and plungers every 400,000 mi or so. When they fail metal debris usually gets sent into the engine oil. I think the newer trucks have a different oil circuit so it doesn't go through the engine before getting to the filter, but still not something you want to have fail on you if possible. There is a gasket between the pump body and head and there are sealing washers on the banjo fittings. I think they are considered single use by cummins but if they are still in good shape (the rubber seal on them isn't chewed up) you can usually reuse them. I usually have replacements on hand for any sealing washers on the fuel system before I open part of it up since you never know what it will look like until you get it off.