Hi Frank;
My 85 300DT still has its original hoses. I have a complete record from Previous owner. No hose was ever changed. I however have a new pair in the spare just incase. The bottom hose is looking a bit roughed up so may be I will change both of them one of these days and keep the old ones as spare.

You are right on electrical components like Alternator. They just go when they want to.

MVK

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One penny saved is three penny earned.

1985 300D Turbo 179,000miles