My 2004.5 3500 CTD has 15K on it. I am changing all the fluids in the axles, transfer case, and manual tranny. I was also going to drain the antifreeze from the radiator and refill it with the HOAT G5 stuff. At this point is it worth changing out the hoses, heater hoses, and thermostat? My parts shop thought I was crazy to do the hoses.

What about the S belt?

I use it to pull my horse trailer and try to maintain it in top condition so not have have an issue when I am on the road with the horses. Thanks for the advice.

 

I've always done them at 100k on all my cars. It's cheap insurance against getting stranded. Your horses will thank you.

 

Ive had cars and trucks with well over 200k on factory hoses and belts, no issues. I did however look at them occasionally. I wouldn't change them at 15k unless they looked liked they needed it.

For hoses, look for soft spots, especially near hose clamps. Also fire up the motor and see if the water pump would be sucking the upper hoses flat.