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Bolt grade

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Would anyone know for sure what grade the water pump bolts are for a 2015 era 300ISB 5.9 Cummins? I can find every spec for them except the grade - Thread pitch, length, size, torque value etc.  I came home today to my coolant on my driveway.  Motorhome hasn’t run in a week, just sitting in the driveway.  One of the grade 10.9 bolts had snapped off the water pump.  I tell ya….some days….

I might add that my torque wrenches all seem to start at 50 Ft-lbs, and I decided to wing it on guessing the Cummins spec of 18 ft-lbs, so that could be a factor.   Smaller torque wrench has since been added to my collection. 😄  


Edited by BradHend
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One of the Dodge Cummins forums says they are M8x1.25x22 on a 2004.5 model.  One of the other diesel truck forums says M8x1.25x20.  Torque calculator on Fastenal site says dry torque of 18.8 ft-lbs and 14.1 ft-lbs if lubricated if it is a grade 8.8 and the values are 26.9 dry/20.2 lubricated if a grade 10.9.

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