Just a little more on the hoses inside the car, given the opinions already expressed in this thread: I doubt they need replacement.

One of my "ambitions" 15 years ago was to find a way to restore the thermostatic heater controls the 240 used before moving to the plastic valves. I collected them in the yards, sometimes taking the time to unclamp and remove the hoses, and other times just using a serrated knife to liberate them. In every case, the hoses looked pristine inside and out, and felt supple, in stark contrast to the look of the exterior heater hoses exposed to heat, oil, and engine movement.

Although kits are available to replace the valve stem seals, I never found a fix for the failing wax thermostat. However, I did learn something about how the environment affects hose life.

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Art Benstein near Baltimore

"Though it is true there are no stupid questions, it seems there is no shortage of false assertions to base them on." -Unknown