If you see oil dripping out of the hose, you know it's bad. But if you don't see oil on the hose, good chance the hose is still good and if there are leaks in the system, it is due to shrunken 30 year old o-rings. Maybe the hotter weather out west is worse on hoses. I have a collection of about 8 hoses from 30 to 35 year old W123 and they all pressure tested good. You can't tell whether a hose leaks or not by looking, you have to pressure test it.

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85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked