Sweptline Showcase
Ditto, the rubber is subject to cracking, heat, melting and rubbing.Quote
PwrWgnDrvr
The copper line is subject to metal fatigue failure from vibration, or abrasion from rubbing.
Rubber hose for high pressure is common on vehicles and is extremely reliable. Brake line pressure is WAY higher than engine oil pressure and EVERY vehicle has rubber brake lines at the steered wheels. That is an extremely critical point and a matter of life or death if it fails.