FishOnOne wrote:
Either way it's leaking and needs to be fixed....Good luck and let's hope your new pump lasts more than ~80k miles.
The shop that customarily services the truck has some gadget that looks not totally unlike a kidney dialysis machine to extract old coolant, flush system with demineralized water, and add the appropriate mix of coolant called for and demineralized water. The shop owner once explained the big reason he invested in the equipment was to insure no air is in the cooling system during a purge/refill, which he said can cause major issues with the HOAT/OAT coolants in use these days. If I recall, the manual says the truck uses a HOAT coolant.