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+--- Thread: X15 116B Fuel Pump Head Replacement (/showthread.php?tid=10258)
X15 116B Fuel Pump Head Replacement - marek4792 - 08-12-2025
Doing a pump head replacement on mine at 780k miles because the check valve started leaking with no fault codes. Plunger was still good. However the rollers can't be sourced, but looks and feels good. Guess Allison over in Haggai was right about these pumps being more robust.. Kinda pricey bastards though, if you want to do both literally cheaper in the long run to get a new pump...
Anyways, here's the part numbers for everything if anyone needs it..
-Fuel pump head kit #6310580PX
-Oring not included #3028349
RE: X15 116B Fuel Pump Head Replacement - tree98 - 08-12-2025
Curious what the symptoms were? Since you said no fault codes.
RE: X15 116B Fuel Pump Head Replacement - marek4792 - 08-12-2025
Well, couple years back it started to sound cammed like the timing was advanced and 1mpg disappeared, and of course a random miss every now and then even with a 6 pack.. I'm gonna keep this posted updated for sure.
RE: X15 116B Fuel Pump Head Replacement - Rawze - 08-14-2025
I have had reports of them still taking out entire engine when they fail. Reports from as little as 500k miles or so.
Best to stick to the 400k miles or 8,000 hours guts replacement schedule if you ask me.
RE: X15 116B Fuel Pump Head Replacement - marek4792 - 12-02-2025
Heck, just doing some simple math on doing the one pump head $1900 (you need two), the fuel actuator awhile back $500, Can't even get tappets and rollers for the 116B... Just recently swapped the rear gear pump $1000 which as of now seems to the source of my mpg and power falling off woes, and random low idle misfire that the ISX is known for because that has mostly disappeared too...
Gained 1+ mpg going over Donner into sunny California even with winter blend fuel..
It is more financially feasible to outright replace the whole fuel pump at the 400k mile/ 8,000 hour interval, or if any failure or engine being lazy symptoms show up prior to.. Mine the weephole and underside of the gear pump behind the main pump was getting dirty which the red engine maker says is ok, which was why it wasn't really paid much attention to at first... New one the weephole is sealed with a threaded plug.. Just my thoughts..