Bleed brakes and clutch lines when installing line extension

R1200RS + R1250RS Forum » 1200 RS technology » Tyres, Brakes and Suspension » Bleed brakes and clutch lines when installing line extension

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#1 | Bleed brakes and clutch lines when installing line extension datum

Tue Jun 17, 2025 4:23 pm

I just installed the Wunderlich handlebar conversion kit, and it looks like I need to install clutch and brake line extensions.
Will I need to bleed the systems or do I simply swap out the old fittings? The instructions from Wunderlich and Hornig do not indicate a bleed is neccessary.

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#2 | RE: Bleed brakes and clutch lines when installing line extension datum

Tue Jun 17, 2025 4:35 pm

most have found it is only the clutch line that needs extending - this is a low pressure system and the tiny amount of air that enters is unlikely to cause a problem from feedback in other threads.

Have you tried releasing cable ties etc to provide some slack?

I think adding an extension on the brake line would need the system bleeding due to the high pressure. An opportunity to change out the brake fluid anyway, especially if asking a workshop to do it as they will have a vacuum bleeder.

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#3 | RE: Bleed brakes and clutch lines when installing line extension datum

Tue Jun 17, 2025 5:06 pm (Last edited: Tue Jun 17, 2025 5:08 pm)

If I remember rightly, operating the levers a few times will purge the system after disconnecting for installing extensions.

No need to do a full bleed. Valid for clutch as well as brake lines.

Dave H likes the post

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#4 | RE: Bleed brakes and clutch lines when installing line extension datum

Tue Jun 17, 2025 5:16 pm

You can also try holding the lever down with a zip-tie overnight. That seems to work well to make the brake pedal work more firmly after a bleed. But I never tried this with a hydraulic clutch.

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