Recipe - Cummins 6.7L ISB Diesel (Ram HD)
Reliability build
Reliability tier: aggregated - verify before ordering, see /disclosure/
Cooling service for towing reliability (modes Water pump failure / Fan clutch failure (overheat while towing)): the 6.7's cooling wears quietly until a grade reveals it. The water pump is era-split (68210961AA vs 68414058AB) and the fan clutch is the classic overheat-under-load culprit; do the pair with fresh coolant on a tow-duty schedule.
Parts
- 6.7 Cummins Water Pump - water pump (68210961AA) (qty 1)
- 6.7 Cummins Water Pump (current service PN 68414058AB) - later-era water pump (68414058AB) - pick by build date/VIN (qty 1)
- 6.7 Cummins Fan Clutch (electronic-controlled) - fan clutch (52014729AC) - the slip that overheats only under tow (qty 1)
- 6.7 Cummins Spec Coolant + SCA - era-correct chemistry, full flush and bleed (qty 1)
Install order
- test the fan clutch: free-spin cold is normal; check engagement and temperature behavior on a grade
- water pump by build date: 68210961AA vs 68414058AB (weeper/bearing signs)
- full coolant flush with the correct chemistry; bleed per procedure
Expected outcome
Stable temps on grades; no tow-day surprises.
Do not
- do not pair a new pump with tired coolant - the chemistry is half the pump's life
Parts budget
About $230-$400 in parts, plus parts we have no price for. It depends on what the diagnosis finds; each option below is what you buy together. Prices marked "at Dave's" are Dave's Auto Center's, the same as in his store; the others are approximate prices from OEM and maker catalogs, rounded (a manufacturer's list price can run higher). Parts only, no labor.
DIY or shop: Either: confident DIY; bleed discipline makes it a shop job for some.