Topic: CB750 K5: oil leak from oil tank line

[Tugboat]

I’ve traced an oil leak to the connection between the rear oil line and the oil tank (behind the oil tank). There’s an aluminum sealing washer there? Do those fail? Or do the lines go bad? The big nut is tight. Just wondering what I’m getting into before I take it apart.

[Tracksnblades1]

I’ve traced an oil leak to the connection between the rear oil line and the oil tank (behind the oil tank). There’s an aluminum sealing washer there? Do those fail? Or do the lines go bad? The big nut is tight. Just wondering what I’m getting into before I take it apart.

Have you checked the aluminum washer for a crack.
In other applications, I've seen these and copper washers work hardened from repetitive
uses. You may research annealing aluminum, or replace them with soft new ones...

[PeWe]

Yamiya sell washers with rubber for rhese lines. A kit for both lines.