Eventually the return hoses get brittle and fuel collects at the base of the injector.

If you're sure fuel is leaking up from the prechambers then you have a compression leak. Get a new heat shield (~$1.50) and torque the injector to 50 lbft. Get an injector socket that fits well or you'll bend the return nipples and you'll have a worse leak.

Sixto
93 300SD