Waterpump has it ever been changed? What is a K2500...GMC gasser? (a guess).
Hey I was on a trip and the waterpump went out on a Saturady night in the rain on I 10 in the FL panhandle next to nowhere. Best thing I had was AAA RV towing card in my wallet. (what's in your wallet?) BTW, I was pulling my boat. They came with two trucks, one to pull boat trailer, it was a flatbed recovery truck and the one that pulled TC was a semi recovery truck...slid the lift under the fronts disconnected the drive line and away we went in the rain...he took me to the place he had his trucks serviced...I washed my truck on Sunday in the parking lot and had a pleasant day, fiddled with my fishing gear and boat a bit, watched TV and slept. At 0730 hrs Monday the owner was there and told me he had a call from the tow guy and said I'd be waiting. He had me on the road in 45 mins from opening the hood...ocst $168...tow was $400 and AAA paid that when I submitted the bill. SO get a tow package it is the best insurance for a long trip.